From eoas-seminar at lists.fsu.edu Fri Mar 1 08:55:47 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Fri, 1 Mar 2019 13:55:47 +0000 Subject: [Eoas-seminar] Meteorology MS Defense for Mengtao Yin, Thursday, March 7, 2019, 3:30 PM, LOV353 Message-ID: Meteorology Seminar Mengtao Yin PhD Meteorology Candidate Title: Understanding Microphysics of Snowflakes and Snow Precipitation Process Using Spaceborne Microwave Measurements Major Professor: Dr. Guosheng Liu Date: March 07, 2019 Time: 3:30 to 6:00 PM Location: Werner A. Baum Seminar Room (353 Love Building) (Please join us for refreshments served outside room 353 Love @ 3:00 PM) ABSTRACT Snow, another precipitation form besides rain, affects the Earth's climate distinctly by modifying hydrological and radiative processes. The radiative properties of nonspherical snowflakes are much more complicated than their spherical counterparts, raindrops. Snowflakes with different structures tend to have different scattering properties. Thus, it is important for us to increase the knowledge in falling snow. However, only a few sensors have been available so far that can provide global snowfall measurements including those onboard he Global Precipitation Measurement (GPM) core observatory and the CloudSat satellites. The GPM satellite carries two important instruments for studying snow precipitations, i.e., the Dual-frequency Precipitation Radar (DPR) and the GPM Microwave Imager (GMI). By combining the GPM instruments with another active sensor onboard the CloudSat satellite, the Cloud Profiling Radar (CPR), an unprecedented opportunity arises for understanding the microphysics of snowflakes and the physical processes of snow precipitation. Seizing this opportunity, in this study, we firstly investigate the microphysical properties of snow particles by analyzing their backscattered signatures at different frequencies. Then, the accuracy of simulating passive microwave brightness temperatures at high frequencies is examined under snowfall conditions using the CPR derived snow water content profiles as radiative transfer model inputs. Lastly, a passive microwave snowfall retrieval method is developed in which the a priori database is optimized by tuning snow water content profiles to be consistent with the GMI observations. This research explores the application of spaceborne microwave measurements to snowfall studies by combining CloudSat and GPM instruments. It provides new knowledge on snowflake microphysics and applicable methods in retrieving three-dimensional snow water distribution from passive high frequency microwave measurements. Please see attachment for full abstract. Shel McGuire Florida State University Academic Program Specialist Department of Earth, Ocean, & Atmospheric Science 1017 Academic Way, 410 Love Building (Meteorology) Tallahassee, FL 32306 850-644-8582 -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: abstract.docx Type: application/vnd.openxmlformats-officedocument.wordprocessingml.document Size: 14521 bytes Desc: abstract.docx URL: From eoas-seminar at lists.fsu.edu Fri Mar 1 12:49:50 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Fri, 1 Mar 2019 17:49:50 +0000 Subject: [Eoas-seminar] REMINDER TODAY - EOAS Colloquium this Friday at 3:30 in CAR 101 Message-ID: This week's EOAS colloquium speaker will be: Dr Peter Weiss University of California, Santa Cruz Atmospheric methylmercury: from the ocean to fog to bioaccumulation in coastal terrestrial apex predators in California Coastal upwelling of ocean water can result in a sea-air flux of the potent yet highly reactive neurotoxin dimethylmercury. Marine stratus clouds are commonly present over the Pacific Ocean off the coast of California during the seasons when upwelling is active (spring and summer). These clouds act as an efficient absorber of dimethylmercury and also of airborne monomethylmercury that may arise from sea spray. As these clouds advect onto land and deposit water as fog drip, they can transfer significant quantities of methylmercury to terrestrial ecosystems. This talk will describe the research that has been conducted since 2011 to quantify methylmercury in fog and marine stratus clouds, and its possible sources and sinks. An investigation of the mercury burdens in the coastal terrestrial food web will also be presented. These results show that methylmercury concentrations in the California mountain lion, mule deer, and lichen (a deer food) are significantly elevated in samples taken from a fog-inundated coastal forest area versus inland areas with no fog. This suggests that while fog drip is a small portion of the hydrologic inputs, the methylmercury it contains may play a disproportionate role in bioaccumulation of mercury in coastal terrestrial food webs. -------------- next part -------------- An HTML attachment was scrubbed... URL: From eoas-seminar at lists.fsu.edu Tue Mar 5 08:25:30 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Tue, 5 Mar 2019 13:25:30 +0000 Subject: [Eoas-seminar] REMINDER: Meteorology MS Defense for Jiangmei Li, Tuesday, March 5, 2019, 3:30 PM, LOV353 Message-ID: Meteorology Seminar Jiangmei Li M.S. Meteorology Candidate Title: Classification of rain clouds based on the relationship between microwave emission and scattering signals Major Professor: Guosheng Liu Date: March 5, 2019 Time: 3:30 - 5:00 PM Location: Werner A. Baum Seminar Room (353 Love Building) (Please join us for refreshments served outside room 353 Love @ 3:00 PM) ABSTRACT In this thesis, we introduce a new approach to classify rain clouds based on the relationship between the emission signal and scattering signal derived from microwave brightness temperature data. Two parameters are used as indicators of emission signal and scattering signal respectively: one is the polarization difference (D) at 19 GHz, and the other one is the polarization-corrected temperature (PCT) at high-frequencies channels. D is related to the emission of liquid hydrometeors, and PCT mainly reflects the brightness temperature depression due to the scattering by ice particles. Both D and PCT decrease with increasing precipitation rate. Therefore, certain combinations of D and PCT can be regarded as the representatives of cloud hydrometeor structures. Based on the D-PCT relationship investigated in this study, we classified the observed rain clouds into five categories-non-precipitating, light-precipitating, liquid-dominant precipitating, well-mix precipitating, and ice-dominant precipitating cloud. We verified the results of the classification of different precipitation cases over tropical regions. For both the hurricane and front cases, the results show that the distributions of categorized cloud pixels can reflect the horizontal structure of the weather systems. The monthly gridded mean frequencies of categorized precipitating clouds are used to analyze the relationship between the seasonal and interannual cycles of tropical precipitation and clouds' hydrometeor components. Moreover, the results indicated that in an annual cycle or an ENSO cycle, when the local precipitation frequencies increase, the occurrence frequencies of all kinds of rain clouds will increase. However, among those precipitating systems, the proportions of ice-dominant and well-mixed clouds increases while that of water-dominant clouds decrease as the local precipitation increases. Anomalies of the opposite sign tend to accompany the decreasing precipitations situations. Overall, the classification method proves to be useful to extract objective information from observed emission and scattering signals. Shel McGuire Florida State University Academic Program Specialist Department of Earth, Ocean, & Atmospheric Science 1017 Academic Way, 410 Love Building (Meteorology) Tallahassee, FL 32306 850-644-8582 -------------- next part -------------- An HTML attachment was scrubbed... URL: From eoas-seminar at lists.fsu.edu Tue Mar 5 12:58:06 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Tue, 5 Mar 2019 17:58:06 +0000 Subject: [Eoas-seminar] EOAS Colloquium speaker this Friday 3:30 in CAR 101 Message-ID: Please join us this Friday Mar 9 for our EOAS speaker at 3:30 in CAR 101: Jeffrey W. Krause Dauphin Island Sea Lab, Dauphin Island, AL 36528 Department of Marine Sciences, University of South Alabama, Mobile, AL 36688 The North Atlantic spring phytoplankton bloom: a new spin on an old story Diatoms? contribution to primary productivity and organic matter export are significant in the high-latitude North Atlantic marine ecosystems. Unlike other abundant phytoplankton groups, diatoms have an obligate silicon requirement; therefore, silicon availability has the potential to regulate major high-latitude events like the spring bloom. Waters in the high-latitude sector of the Atlantic (e.g. coastal Greenland, Faroe Islands, Barents Sea, Svalbard) have lower pre-bloom silicic acid concentrations than nitrate. Given diatoms require Si and N in near unity, the deplete Si relative to N sets a potential control on diatom productivity in this system, such that Si could limit diatom biomass yield in a bloom. Recent publications have reported 20-year declines in silicic acid concentrations between ~60 ? 75 ?N latitude in the Atlantic. Despite the clear changes in Si availability, there are no reported data for the magnitude of diatom Si uptake and whether ambient silicic acid limits silicon uptake by diatoms or their growth. Here we report data from the West Greenlandic Nuup Kangerlua fjord during the development of the spring bloom over two months at a time-series site. This site is influenced by the subpolar mode water, Greenland coastal water and early-season glacial melt water. The ambient silicic acid persistently limited the rate of Si uptake by diatoms and eventually limited their growth at the bloom peak. Temporally concurrent with growth limitation by silicic acid availability, diatom settling velocity increased to pre-bloom levels, reflective of physiological stress, and an increase in the number of dead cells among the total diatom assemblage. These data suggests that silicon availability plays an important role in terminating the spring bloom in this region when diatoms are favored to dominate the bloom sequence. -------------- next part -------------- An HTML attachment was scrubbed... URL: From eoas-seminar at lists.fsu.edu Thu Mar 7 09:38:14 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Thu, 7 Mar 2019 14:38:14 +0000 Subject: [Eoas-seminar] Reminder: Geology Thesis Defense - Megan Shelfer - March 8, 10:00 - 104CAR Message-ID: Title: Humicrete in Northwest Florida: An Analysis of Formation and Characteristics Major Professor: Steven Kish -------------- next part -------------- An HTML attachment was scrubbed... URL: From eoas-seminar at lists.fsu.edu Thu Mar 7 10:24:52 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Thu, 7 Mar 2019 15:24:52 +0000 Subject: [Eoas-seminar] TODAY: Meteorology MS Defense for Mengtao Yin, Thursday, March 7, 2019, 3:30 PM, LOV353 Message-ID: Meteorology Seminar Mengtao Yin PhD Meteorology Candidate Title: Understanding Microphysics of Snowflakes and Snow Precipitation Process Using Spaceborne Microwave Measurements Major Professor: Dr. Guosheng Liu Date: March 07, 2019 Time: 3:30 to 6:00 PM Location: Werner A. Baum Seminar Room (353 Love Building) (Please join us for refreshments served outside room 353 Love @ 3:00 PM) ABSTRACT Snow, another precipitation form besides rain, affects the Earth's climate distinctly by modifying hydrological and radiative processes. The radiative properties of nonspherical snowflakes are much more complicated than their spherical counterparts, raindrops. Snowflakes with different structures tend to have different scattering properties. Thus, it is important for us to increase the knowledge in falling snow. However, only a few sensors have been available so far that can provide global snowfall measurements including those onboard he Global Precipitation Measurement (GPM) core observatory and the CloudSat satellites. The GPM satellite carries two important instruments for studying snow precipitations, i.e., the Dual-frequency Precipitation Radar (DPR) and the GPM Microwave Imager (GMI). By combining the GPM instruments with another active sensor onboard the CloudSat satellite, the Cloud Profiling Radar (CPR), an unprecedented opportunity arises for understanding the microphysics of snowflakes and the physical processes of snow precipitation. Seizing this opportunity, in this study, we firstly investigate the microphysical properties of snow particles by analyzing their backscattered signatures at different frequencies. Then, the accuracy of simulating passive microwave brightness temperatures at high frequencies is examined under snowfall conditions using the CPR derived snow water content profiles as radiative transfer model inputs. Lastly, a passive microwave snowfall retrieval method is developed in which the a priori database is optimized by tuning snow water content profiles to be consistent with the GMI observations. This research explores the application of spaceborne microwave measurements to snowfall studies by combining CloudSat and GPM instruments. It provides new knowledge on snowflake microphysics and applicable methods in retrieving three-dimensional snow water distribution from passive high frequency microwave measurements. Please see attachment for full abstract. Shel McGuire Florida State University Academic Program Specialist Department of Earth, Ocean, & Atmospheric Science 1017 Academic Way, 410 Love Building (Meteorology) Tallahassee, FL 32306 850-644-8582 -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: abstract.docx Type: application/vnd.openxmlformats-officedocument.wordprocessingml.document Size: 14521 bytes Desc: abstract.docx URL: From eoas-seminar at lists.fsu.edu Fri Mar 8 13:01:03 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Fri, 8 Mar 2019 18:01:03 +0000 Subject: [Eoas-seminar] REMINDER TODAY EOAS Colloquium speaker this Friday 3:30 in CAR 101 In-Reply-To: References: Message-ID: Please join us Today, Mar 9 for our EOAS speaker at 3:30 in CAR 101: Jeffrey W. Krause Dauphin Island Sea Lab, Dauphin Island, AL 36528 Department of Marine Sciences, University of South Alabama, Mobile, AL 36688 The North Atlantic spring phytoplankton bloom: a new spin on an old story Diatoms? contribution to primary productivity and organic matter export are significant in the high-latitude North Atlantic marine ecosystems. Unlike other abundant phytoplankton groups, diatoms have an obligate silicon requirement; therefore, silicon availability has the potential to regulate major high-latitude events like the spring bloom. Waters in the high-latitude sector of the Atlantic (e.g. coastal Greenland, Faroe Islands, Barents Sea, Svalbard) have lower pre-bloom silicic acid concentrations than nitrate. Given diatoms require Si and N in near unity, the deplete Si relative to N sets a potential control on diatom productivity in this system, such that Si could limit diatom biomass yield in a bloom. Recent publications have reported 20-year declines in silicic acid concentrations between ~60 ? 75 ?N latitude in the Atlantic. Despite the clear changes in Si availability, there are no reported data for the magnitude of diatom Si uptake and whether ambient silicic acid limits silicon uptake by diatoms or their growth. Here we report data from the West Greenlandic Nuup Kangerlua fjord during the development of the spring bloom over two months at a time-series site. This site is influenced by the subpolar mode water, Greenland coastal water and early-season glacial melt water. The ambient silicic acid persistently limited the rate of Si uptake by diatoms and eventually limited their growth at the bloom peak. Temporally concurrent with growth limitation by silicic acid availability, diatom settling velocity increased to pre-bloom levels, reflective of physiological stress, and an increase in the number of dead cells among the total diatom assemblage. These data suggests that silicon availability plays an important role in terminating the spring bloom in this region when diatoms are favored to dominate the bloom sequence. -------------- next part -------------- An HTML attachment was scrubbed... URL: From eoas-seminar at lists.fsu.edu Mon Mar 11 10:31:35 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Mon, 11 Mar 2019 14:31:35 +0000 Subject: [Eoas-seminar] Next EOAS Colloquium Mar 29 Message-ID: This is a faculty meeting week so there will be no seminar. Next week is Spring Break, also no seminar, so our next EOAS colloquium will be Friday Mar 29 at 3:30.? Dr Tracey Sutton of Nova Southeastern University will be our speaker and his talk title is forthcoming. From eoas-seminar at lists.fsu.edu Thu Mar 14 16:37:49 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Thu, 14 Mar 2019 20:37:49 +0000 Subject: [Eoas-seminar] REMINDER: Meteorology MS Defense for Brittany MacNamara, Thursday, March 28, 2019, 1:00 PM, LOV353 Message-ID: Meteorology Seminar Brittany MacNamara M.S. Meteorology Candidate Title: FLash characteristics and precipitation metrics of western u.s. lightning-initiated wildfires Major Professor: Dr. Henry Fuelberg Date: March 28, 2019 Time: 1:00 PM Location: Werner A. Baum Seminar Room (353 Love Building) (Please join us for refreshments served outside room 353 Love @ 12:30 PM) ABSTRACT The United States Forest Service (USFS) bases their wildfire predictions on cloud-to-ground lightning flash density thresholds greater than 5 fl km-2. High flash densities and low precipitation are often emphasized with storms since they are associated with wildfire ignitions. Yet, greater flash rates tend to occur in the areas of greatest rainfall. This study focuses on 95 lightning-initiated wildfires in the western United States during the year of 2017. Lightning data provided by the National Lightning Detection Network (NLDN) were analyzed to determine which strike(s) likely caused each fire, as well as the strikes that did not. Detailed analysis of cloud-to-ground lightning characteristics and thunderstorm characteristics such as stroke density, precipitation rate, and 24-h storm-relative QPE totals are presented. Statistical analyses using a Wilcoxon-Mann Whitney rank sum test were performed to reveal differences between lightning flashes that ignite wildfires and those that do not. Results indicate multiple-stroke negative polarity cloud-to-ground flashes dominated the fire starts. In addition, wildfires were initiated in areas with low stroke densities. Based on these tentative findings, the USFS may need to revisit their methods for wildland fire prediction. Rain rates at the locations of fire starts were 8.03 mm h-1 less than those of non-fire starting flashes, while 24-h QPE totals were 5.28 mm less. These differences were found to be statistically significant. The results of this thesis will help expand the limited knowledge of operational lightning and wildfire meteorology. However, considerable additional research is needed. Shel McGuire Florida State University Academic Program Specialist Department of Earth, Ocean, & Atmospheric Science 1017 Academic Way, 410 Love Building (Meteorology) Tallahassee, FL 32306 850-644-8582 -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: MacNamara Seminar.docx Type: application/vnd.openxmlformats-officedocument.wordprocessingml.document Size: 22572 bytes Desc: MacNamara Seminar.docx URL: From eoas-seminar at lists.fsu.edu Thu Mar 14 16:40:35 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Thu, 14 Mar 2019 20:40:35 +0000 Subject: [Eoas-seminar] REMINDER: Meteorology PhD Defense for Danielle Groenen, Thursday, March 28, 2019, 3:30 PM, LOV353 Message-ID: Meteorology Seminar Danielle Groenen PhD Meteorology Candidate Title: Diagnosing the Atmospheric Phenomena Associated with the Onset and Demise of the Mesoamerican Rainy Season Major Professor: Dr. Mark Bourassa Date: Thursday, March 28, 2019 Time: 3:30 PM Location: Werner A. Baum Seminar Room (353 Love Building) (Please join us for refreshments served outside room 353 Love @ 3:00 PM) ABSTRACT Mexico and Central America (Mesoamerica) are situated in a complex and unique geographical position with the Caribbean Sea to the East and the tropical Eastern Pacific Ocean to the West. The weather patterns of this region are driven by winds, temperatures, moisture, and orography of several mountain ranges. The Mesoamerican Rainy Season has traditionally been defined as May through November each year, and past studies often use monthly climatologies when analyzing the phenomenology associated with the rainfall. However, key crops grown in Mesoamerica such as bananas, coffee, corn, cacao, and rice require more detail on a daily-to weekly temporal scale. This study finds the dates of the onset and demise of rainfall regimes on a specific day using NASA's Tropical Rainfall Measuring Mission (TRMM) rainfall for years 1998-2012, area-averaged over land. Using NASA's MERRA-2 Reanalysis data, we also look at the phenomenology of the triggers of the rainy season onset and demise on the daily time-scale instead of the monthly scales used by previous studies. We find that the Mesoamerican Rainy Season can be distinguished into two parts: the Early Spring Rainfall (ESR) associated with light rains and the Late Spring Rainfall (LSR) associated with heavy rains. Two algorithms are used to obtain these rainy season distinctions. A new algorithm was developed during this study, to calculate when the rainfall first starts to increase. The daily cumulative anomalies of rainfall are compared to the climatological rainfall to find the time of onset of the heavy rains. To better understand the phenomenology associated with the timing of the rainfall, we look at the monsoon trough, moisture flux convergence, and the weakening/strengthening of the winds associated with the Caribbean Low-Level Jet and Panama Jet. The light rainfall begins, on average, in mid-March, approximately one month after the peak of the winter Caribbean Low-Level Jet and the Panama Jet. The ramp-up between the light rains and heavy rains is associated with a significant weakening of both jets and the northward progression of a monsoon trough off the western coast of Central America. The heavy rains begin, on average, in mid-May, and are associated with the timing when the Panama Jet goes to near zero magnitude. We find the rainfall onsets materialize first, which then change the wind patterns and regional moisture convergence. The rainfall onsets are followed by a positive total moisture flux convergence in the entire domain. At the demise of the rainfall, approximately in mid-November, the Panama Jet strengthens again and the total moisture flux convergence decreases significantly. The results of this study have positive implications in agriculture and water resources for Mesoamerica, as this information may help resource managers better plan and adapt to climate variability. Shel McGuire Florida State University Academic Program Specialist Department of Earth, Ocean, & Atmospheric Science 1017 Academic Way, 410 Love Building (Meteorology) Tallahassee, FL 32306 850-644-8582 -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Groenen Seminar.docx Type: application/vnd.openxmlformats-officedocument.wordprocessingml.document Size: 22711 bytes Desc: Groenen Seminar.docx URL: From eoas-seminar at lists.fsu.edu Fri Mar 15 12:38:02 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Fri, 15 Mar 2019 16:38:02 +0000 Subject: [Eoas-seminar] Tracey Sutton visit Message-ID: Dr. Tracey Sutton from Nova Southeastern University will be our EOAS speaker on Friday Mar 29.? Among his many research interests, he is the lead PI on the GOMRI DEEPEND consortium, http://sutton.deependconsortium.org/??? He is here for the whole day, if you would like to meet with him, please email me at abacotaylor at fsu.edu with your preferred time or meal slot. -- Amy Baco-Taylor, PhD Associate Professor Earth, Ocean, and Atmospheric Sciences Florida State University (850) 645-1547 abacotaylor at fsu.edu From eoas-seminar at lists.fsu.edu Fri Mar 15 13:22:20 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Fri, 15 Mar 2019 17:22:20 +0000 Subject: [Eoas-seminar] REMINDER: Meteorology MS Defense for Jacob Carstens, Monday, April 1, 2019, 4:00 PM, LOV353 Message-ID: Meteorology Seminar Jacob Carstens M.S. Meteorology Candidate Title: Tropical cyclogenesis from self-aggregated convection in numerical simulations of rotating radiative-convective equilibrium Major Professor: Dr. Allison Wing Date: April 01, 2019 Time: 4:00-5:30 PM Location: Werner A. Baum Seminar Room (353 Love Building) (Please join us for refreshments served outside room 353 Love @ 3:30 PM) ABSTRACT Organized convection is of critical importance in the tropical atmosphere. Recent advances in numerical modeling have revealed that moist convection can interact with its environment to transition from a quasi-random to organized state. This phenomenon, known as convective self-aggregation, is aided by feedbacks involving clouds, water vapor, and radiation that increase the spatial variance of column-integrated frozen moist static energy. Prior studies have shown self-aggregation to take several different forms, including that of spontaneous tropical cyclogenesis in an environment of rotating radiative-convective equilibrium (RCE). This study expands upon previous work to address the processes leading to tropical cyclogenesis in this rotating RCE framework. More specifically, a 3-D, cloud-permitting numerical model is used to examine the self-aggregation of convection and potential cyclogenesis, and the background planetary vorticity is varied on an f-plane across simulations to represent a range of deep tropical and near-equatorial environments. Convection is initialized randomly in an otherwise homogeneous environment, with no background wind, precursor disturbance, or other synoptic-scale forcing. All simulations with planetary vorticity corresponding to latitudes from 10? poleward generate intense tropical cyclones, with maximum wind speeds of 80 ms-1 or above. Time to genesis and to hurricane intensity varies widely, even within a 5-member ensemble of 20? simulations, reflecting a potential degree of stochastic variability based in part on the initial random distribution of convection. Shared across this so-called "high-f" group is the emergence of a midlevel vortex in the days leading to genesis, which has dynamic and thermodynamic implications on its environment that facilitates the spinup of a low-level vortex. Tropical cyclogenesis is possible in this model even at very low values of Coriolis parameter, as far equatorward as 1?. In these experiments, convection self-aggregates into a quasi-circular cluster, which then begins to rotate and gradually strengthens into a tropical storm, aided by near-surface inflow and elevated overturning radial circulations within the aggregated cluster. Other experiments at these lower Coriolis parameters instead self-aggregate into an elongated band and fail to undergo cyclogenesis over the 100-day simulation. A large portion of this study is devoted to examining in greater detail the dynamic and thermodynamic evolution of cyclogenesis in these experiments and comparing the physical mechanisms to current theories. Shel McGuire Florida State University Academic Program Specialist Department of Earth, Ocean, & Atmospheric Science 1017 Academic Way, 410 Love Building (Meteorology) Tallahassee, FL 32306 850-644-8582 -------------- next part -------------- An HTML attachment was scrubbed... URL: From eoas-seminar at lists.fsu.edu Fri Mar 15 13:22:52 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Fri, 15 Mar 2019 17:22:52 +0000 Subject: [Eoas-seminar] REMINDER: Meteorology MS Defense for Shannon Shields, Tuesday, April 2, 2019, 3:30 PM, LOV353 Message-ID: Meteorology Seminar Shannon Shields M.S. Meteorology Candidate Title: Potential Intensity and Lifetime Maximum Intensity Interannual Variability of Tropical Cyclones: An Analysis on Influential Factors Major Professor: Dr. Allison Wing Date: April 2, 2019 Time: 3:30-5:00 PM Location: Werner A. Baum Seminar Room (353 Love Building) (Please join us for refreshments served outside room 353 Love @ 3:00 PM) ABSTRACT Many tropical cyclone studies have been conducted on basin-averaged potential intensity trends and the influence of sea surface temperatures (SSTs) on tropical cyclone intensity, but there is less research on along-track potential intensity (PI) and lifetime maximum intensity (referred to here as actual intensity or AI) and the factors that influence their variability. Potential intensity is a theory that predicts the maximum intensity that a tropical cyclone can achieve given certain large-scale environmental variables. Understanding interannual variability in PI and its relation to AI interannual variability is of great importance for assessing the impact of future climate conditions on tropical cyclones. Theoretically, warmer SSTs and cooler outflow temperatures would cause an increase in overall PI which in turn would lead to an increase in AI. This thesis examined the relationship between PI and AI on interannual time scales and the factors affecting PI variability: thermodynamic efficiency and air-sea enthalpy disequilibrium. Using best-track data and three reanalysis products, variability in PI and AI was examined for the North Atlantic, North Indian, South Indian, South Pacific, Eastern North Pacific, and Western North Pacific basins from 1980-2013. Overall, the Western North Pacific was the only basin that yielded high and consistently significant correlations between AI and PI. Despite the expectation from a previous study, the North Atlantic did not yield any significant correlations. Multiple tests were then conducted to determine the sensitivity of the North Atlantic correlations to different datasets and time periods. Ultimately, it was determined that the North Atlantic AI vs. PI correlation results were very dependent upon the time period and the individual years within the time period. In the comparison of all contributors, air-sea disequilibrium was the dominant contributor to PI variability. When AI variability was correlated with PI variability, disequilibrium (which is largely controlled by SSTs) was also the dominant contributor to AI variability. Although disequilibrium was the dominant factor in PI and AI interannual variability, efficiency also played a role. In fact, this study found that variances in efficiency explained 13-93% of PI interannual variability, indicating that variability in outflow temperatures (which cause much of the variability in efficiency) must be taken into account. Shel McGuire Florida State University Academic Program Specialist Department of Earth, Ocean, & Atmospheric Science 1017 Academic Way, 410 Love Building (Meteorology) Tallahassee, FL 32306 850-644-8582 -------------- next part -------------- An HTML attachment was scrubbed... URL: From eoas-seminar at lists.fsu.edu Fri Mar 15 13:24:38 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Fri, 15 Mar 2019 17:24:38 +0000 Subject: [Eoas-seminar] REMINDER: Meteorology MS Defense for Allison Ronan, Wednesday, April 3, 2019, 1:00 PM, LOV353 Message-ID: Meteorology Seminar Allison Ronan M.S. Meteorology Candidate Title: HAVE IMPROVEMENTS IN OZONE AIR QUALITY BENEFITTED PLANTS? Major Professor: Dr. Christopher D. Holmes Date: April 3rd, 2019 Time: 1:00 PM Location: Werner A. Baum Seminar Room (353 Love Building) (Please join us for refreshments served outside room 353 Love @ 12:30 PM) ABSTRACT Surface ozone (O3) is a toxic air pollutant. In the United States and Europe, among other places, policies and technology have reduced emissions of O3 precursors the last couple decades. As a result, peak levels of O3, quantified by concentration metrics such as maximum daily average over 8 hours (MDA8), the accumulated O3 exposure over a threshold of 40 ppb (AOT40), and W126 have fallen. Influential past studies have assumed that these improvements in AOT40 and W126 imply reductions in plant injury, even though it is widely recognized that O3 flux into leaves is a better predictor of plant at damage than ambient concentration in air. Concentration metrics remain widely used because O3 concentrations measurements are more common and because concentration and flux are correlated when the variability of stomatal conductance is limited. We use a new dataset of O3 flux into plants to quantify decadal trends in the cumulative uptake of O3 (CUO) into leaf stomata for the first time. We examine 32 sites in the United States and Europe over 2005-2014 and find that the AOT40 and W126 concentration metrics decreased at 25 and 28 sites, respectively, whereas CUO increased a majority of sites (18). The divergent trends are due to stomatal control of flux, which is shaped by environmental variability. As a result, there has been no widespread, clear improvement in CUO over 2005-2014 at the sites we can assess. We use several statistical tests to show that temporal trends and variability in CUO are uncorrelated with AOT40, W126, and mean concentration (R2 [cid:image001.png at 01D4DB32.70159F60] 0.15). Decreases in concentration metrics, therefore, give a falsely optimistic picture of the direction and magnitude of O3 impacts on vegetation. Because of this lack of relation between flux and concentration, flux metrics should be preferred over concentration metrics in assessments of plant injury from O3. GEOS-Chem is a 3-D global atmospheric chemistry model that uses meteorological input to simulate atmospheric composition. We evaluate the model's ability to estimate O3 deposition velocity ([cid:image002.png at 01D4DB32.70159F60]) by running a simulation during the same period as the surface O3 trend analysis. By comparing monthly output of [cid:image002.png at 01D4DB32.70159F60] from GEOS-Chem to our observations using the SynFlux dataset, we find that GEOS-Chem consistently underestimates [cid:image002.png at 01D4DB32.70159F60] . The degree of the underestimation depends on the land class type as well as the time of year. We attempt to improve the model output by prescribing the land class type within the model to match the plant functional types at the FLUXNET sites. This did not lead to a significant improvement and in many cases, this led to a wider gap between the model and observations. We discuss possible reasons for the discrepancy between the model and observations. Improving [cid:image002.png at 01D4DB32.70159F60] in the model would better estimate dry deposition of O3, which is important for simulating air quality and its impacts to humans and plants. Shel McGuire Florida State University Academic Program Specialist Department of Earth, Ocean, & Atmospheric Science 1017 Academic Way, 410 Love Building (Meteorology) Tallahassee, FL 32306 850-644-8582 -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: image001.png Type: image/png Size: 249 bytes Desc: image001.png URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: image002.png Type: image/png Size: 391 bytes Desc: image002.png URL: From eoas-seminar at lists.fsu.edu Fri Mar 15 15:52:52 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Fri, 15 Mar 2019 19:52:52 +0000 Subject: [Eoas-seminar] Correction: REMINDER: Meteorology MS Defense for Shannon Shields, Tuesday, April 2, 2019, 3:30 PM, LOV353 Message-ID: Meteorology Seminar Shannon Shields M.S. Meteorology Candidate Title: Interannual Variability of Tropical cyclone Potential Intensity and Lifetime Maximum Intensity: An Analysis of Influential Factors Major Professor: Dr. Allison Wing Date: April 2, 2019 Time: 3:30-5:00 PM Location: Werner A. Baum Seminar Room (353 Love Building) (Please join us for refreshments served outside room 353 Love @ 3:00 PM) ABSTRACT Many tropical cyclone studies have been conducted on basin-averaged potential intensity trends and the influence of sea surface temperatures (SSTs) on tropical cyclone intensity, but there is less research on along-track potential intensity (PI) and lifetime maximum intensity (referred to here as actual intensity or AI) and the factors that influence their variability. Potential intensity is a theory that predicts the maximum intensity that a tropical cyclone can achieve given certain large-scale environmental variables. Understanding interannual variability in PI and its relation to AI interannual variability is of great importance for assessing the impact of future climate conditions on tropical cyclones. Theoretically, warmer SSTs and cooler outflow temperatures would cause an increase in overall PI which in turn would lead to an increase in AI. This thesis examined the relationship between PI and AI on interannual time scales and the factors affecting PI variability: thermodynamic efficiency and air-sea enthalpy disequilibrium. Using best-track data and three reanalysis products, variability in PI and AI was examined for the North Atlantic, North Indian, South Indian, South Pacific, Eastern North Pacific, and Western North Pacific basins from 1980-2013. Overall, the Western North Pacific was the only basin that yielded high and consistently significant correlations between AI and PI. Despite the expectation from a previous study, the North Atlantic did not yield any significant correlations. Multiple tests were then conducted to determine the sensitivity of the North Atlantic correlations to different datasets and time periods. Ultimately, it was determined that the North Atlantic AI vs. PI correlation results were very dependent upon the time period and the individual years within the time period. In the comparison of all contributors, air-sea disequilibrium was the dominant contributor to PI variability. When AI variability was correlated with PI variability, disequilibrium (which is largely controlled by SSTs) was also the dominant contributor to AI variability. Although disequilibrium was the dominant factor in PI and AI interannual variability, efficiency also played a role. In fact, this study found that variances in efficiency explained 13-93% of PI interannual variability, indicating that variability in outflow temperatures (which cause much of the variability in efficiency) must be taken into account. Shel McGuire Florida State University Academic Program Specialist Department of Earth, Ocean, & Atmospheric Science 1017 Academic Way, 410 Love Building (Meteorology) Tallahassee, FL 32306 850-644-8582 -------------- next part -------------- An HTML attachment was scrubbed... URL: From eoas-seminar at lists.fsu.edu Mon Mar 18 09:15:14 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Mon, 18 Mar 2019 13:15:14 +0000 Subject: [Eoas-seminar] Oceanography Thesis Defense - Rachel Petet - March 28, 10am - CSL1005 Message-ID: Oceanography Seminar Rachel Petet M.S. Biological Oceanography Candidate Title: Impacts of microbial community structure on denitrification rates in the rhizosphere of J. roemerianus and S. alterniflora collocated in a Gulf of Mexico saltwater marsh Major Professor: Dr. Olivia U. Mason Date: March 28rd, 2019 Time: 10:00 AM Location: Chemistry 1005 (CSL 1005) ABSTRACT Marshes are particularly important ecosystems, providing long-term soil carbon storage, flood protection and nutrient filtration. Nutrient filtering, specifically nitrate removal, is largely the result of belowground microbially mediated denitrification. Denitrification rates differ in Spartina alterniflora and Juncus roemerianus patches but determining how the associated microbial communities contribute to these differences is challenged by the inherent physicochemical variability in the belowground of plants at different elevations in the marsh. Here we had a unique opportunity to evaluate denitrification rates and the belowground microbial community in J. roemerianus and S. alterniflora collocated at the same elevation, thus experiencing the same inundation cycles, in a saltwater marsh. To determine denitrification rates sediment slurry incubations (15N-nitrate) were used. The microbial community structure was determined using "iTag" sequencing of 16S rRNA gene amplicons. Slurry experiments revealed that denitrification rates were consistently higher in J. roemerianus. Analysis of 16S rRNA exact amplicon sequence variants (ASVs) showed that the microbial communities were similar in both plant types, although significant oscillations in abundance of some ASVs was observed. To link the rate and microbial community data, Random Forest Modeling (RFM) was used to determine if specific microbes could be accurate predictors of higher or lower denitrification rates. RFM identified ASVs classified as Deltaproteobacteria; Desulfobacteraceae and Chloroflexi; Anaerolineaceae as the most important predictors of denitrification rates. These microbial predictors were also identified as core members of the rhizosphere of both plants. Desulfobacteraceae, indicates higher denitrification rates, while Anaerolineaceae points towards lower rates of nitrate removal. Desulfobacteraceae are known sulfate reducers, however some have been shown to utilize both nitrate and sulfate to grow chemolithoautotrophically by coupling sulfide oxidation to dissimilatory nitrate reduction. In fact, this pathway was identified in a complimentary metagenomic dataset. Collectively, our data revealed that J. roemerianus promoted greater belowground nitrate removal compared to S. alterniflora which may result from different plant characteristics that lead to oscillations in the abundance of core members of the microbial community that can serve as predictors of denitrification rates and that this reaction may be mediated by previously unsuspected sulfate reducing bacteria in our saltmarsh ecosystem -------------- next part -------------- An HTML attachment was scrubbed... URL: From eoas-seminar at lists.fsu.edu Mon Mar 25 09:52:46 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Mon, 25 Mar 2019 13:52:46 +0000 Subject: [Eoas-seminar] Geology Thesis Defense - Emily Benayoun - April 5, 9am - CAR104 Message-ID: Title: Investigation of changes in paleoceanographic redox state as a driver for early Silurian extinction events using multiple geochemical proxies in the Baltic Basin Major Professor: Seth Young -------------- next part -------------- An HTML attachment was scrubbed... URL: From eoas-seminar at lists.fsu.edu Mon Mar 25 09:58:03 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Mon, 25 Mar 2019 13:58:03 +0000 Subject: [Eoas-seminar] Oceanography Dissertation Defense - Lauren Campbell - April 2, 10am - CSL1005 Message-ID: Oceanography Seminar Lauren Gillies Campbell Ph.D. Biological Oceanography Candidate Title: Analysis of microbial abundance, transcriptional activity and metabolic potential in the Gulf of Mexico "dead zone" reveals an ammonia-oxidizing hotspot Major Professor: Dr. Olivia U. Mason Defense Date: April 2, 2019 Time: 10:00 AM Location: Chemistry 1005 (CSL1005) Abstract: Ocean deooxygenation is accelerating as a result of greenhouse gas-driven atmospheric warming and subsequent increase in global ocean temperature. One of the world's largest coastal hypoxic zones occurs annually in the northern Gulf of Mexico (nGOM). These hypoxic zones are also known as "dead zones" because dissolved oxygen (DO) concentrations of ? 2 mg L-1 are inhospitable to economically valuable fisheries. However, microorganisms flourish in "dead zones" because of their ability to utilize diverse metabolic pathways. Decades worth of geochemical data has provided fine-scale resolution on nutrient and oxygen dynamics the nGOM, however little is known about microbial community structure and activity despite the implication that microbial respiration is responsible for forming low DO conditions. To begin to fill this knowledge gap, samples collected across the nGOM shelf for two consecutive hypoxic seasons in July 2013 (Y13) and 2014 (Y14) were analyzed using 16S rRNA gene iTag sequencing, quantification of bacterial and thaumarchaeal 16S rRNA genes and archaeal ammonia-monooxygenase (amoA) genes using quantitative polymerase chain reaction (qPCR) assays, as well as shotgun metagenomic and metatranscriptomic sequencing. Analysis of the microbial community16S rRNA gene sequence data (iTag) showed that ammonia-oxidizing Thaumarchaeota (100% similar to Nitrosopumilus maritimus) were significantly enriched in hypoxic samples and inversely correlated with DO concentrations. In agreement with the iTag data, subsequent analyses of the absolute abundance (qPCR) of Thaumarchaeota 16S rRNA and amoA gene copy numbers revealed these data to be significantly more abundant in hypoxic samples and inversely correlated with DO concentrations. These results of significantly higher Thaumarchaeota abundances and amoA gene copy numbers in hypoxic samples were confirmed with analyses of Y14 data. To better understand the ecological significance of the high thaumarchaeal abundances in the hypoxic zone, shotgun metagenomic and metatranscriptomic sequencing was carried out. Annotation of unassembled metatranscriptomic reads revealed that functional genes involved in nitrification and ammonia assimilation were some of the most abundant transcripts in both hypoxic and oxic samples, with urease enzymes being significantly more abundant in hypoxic samples. Next, the physiological and metabolic potential of two novel Thaumarchaeota metagenome assembled genomes (MAGs) was described. Bioinformatic analyses of these MAGs revealed that one contained transcripts coding for urea utilization, consistent with the analysis of unassembled metatranscriptomic sequences. Both MAGs recruited more metatranscriptomic reads derived from hypoxic samples compared to oxic samples, suggesting that archaeal ammonia oxidation (AOA) may be influenced by local changes in DO concentrations. Collectively, analyses of the datasets in this dissertation that include data from iTag sequencing, qPCR assays, and meta-omics sequencing, found that seasonal hypoxic conditions influenced Thaumarchaeota abundance, activity and diversity, with the annual nGOM "dead zone" emerging as a niche for low DO-adapted, cosmopolitan AOA. Overall, the findings in this dissertation provided significant new insights into the ecology and biogeochemical contributions of marine Archaea, particularly in regards to the nitrogen cycle during a eutrophic-driven hypoxic event. -------------- next part -------------- An HTML attachment was scrubbed... URL: From eoas-seminar at lists.fsu.edu Mon Mar 25 10:04:32 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Mon, 25 Mar 2019 14:04:32 +0000 Subject: [Eoas-seminar] REMINDER: Meteorology PhD Defense for Danielle Groenen, Thursday, March 28, 2019, 3:30 PM, LOV353 Message-ID: Meteorology Seminar Danielle Groenen PhD Meteorology Candidate Title: Diagnosing the Atmospheric Phenomena Associated with the Onset and Demise of the Mesoamerican Rainy Season Major Professor: Dr. Mark Bourassa Date: Thursday, March 28, 2019 Time: 3:30 PM Location: Werner A. Baum Seminar Room (353 Love Building) (Please join us for refreshments served outside room 353 Love @ 3:00 PM) ABSTRACT Mexico and Central America (Mesoamerica) are situated in a complex and unique geographical position with the Caribbean Sea to the East and the tropical Eastern Pacific Ocean to the West. The weather patterns of this region are driven by winds, temperatures, moisture, and orography of several mountain ranges. The Mesoamerican Rainy Season has traditionally been defined as May through November each year, and past studies often use monthly climatologies when analyzing the phenomenology associated with the rainfall. However, key crops grown in Mesoamerica such as bananas, coffee, corn, cacao, and rice require more detail on a daily-to weekly temporal scale. This study finds the dates of the onset and demise of rainfall regimes on a specific day using NASA's Tropical Rainfall Measuring Mission (TRMM) rainfall for years 1998-2012, area-averaged over land. Using NASA's MERRA-2 Reanalysis data, we also look at the phenomenology of the triggers of the rainy season onset and demise on the daily time-scale instead of the monthly scales used by previous studies. We find that the Mesoamerican Rainy Season can be distinguished into two parts: the Early Spring Rainfall (ESR) associated with light rains and the Late Spring Rainfall (LSR) associated with heavy rains. Two algorithms are used to obtain these rainy season distinctions. A new algorithm was developed during this study, to calculate when the rainfall first starts to increase. The daily cumulative anomalies of rainfall are compared to the climatological rainfall to find the time of onset of the heavy rains. To better understand the phenomenology associated with the timing of the rainfall, we look at the monsoon trough, moisture flux convergence, and the weakening/strengthening of the winds associated with the Caribbean Low-Level Jet and Panama Jet. The light rainfall begins, on average, in mid-March, approximately one month after the peak of the winter Caribbean Low-Level Jet and the Panama Jet. The ramp-up between the light rains and heavy rains is associated with a significant weakening of both jets and the northward progression of a monsoon trough off the western coast of Central America. The heavy rains begin, on average, in mid-May, and are associated with the timing when the Panama Jet goes to near zero magnitude. We find the rainfall onsets materialize first, which then change the wind patterns and regional moisture convergence. The rainfall onsets are followed by a positive total moisture flux convergence in the entire domain. At the demise of the rainfall, approximately in mid-November, the Panama Jet strengthens again and the total moisture flux convergence decreases significantly. The results of this study have positive implications in agriculture and water resources for Mesoamerica, as this information may help resource managers better plan and adapt to climate variability. Shel McGuire Florida State University Academic Program Specialist Department of Earth, Ocean, & Atmospheric Science 1017 Academic Way, 410 Love Building (Meteorology) Tallahassee, FL 32306 850-644-8582 -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Groenen Seminar.docx Type: application/vnd.openxmlformats-officedocument.wordprocessingml.document Size: 22711 bytes Desc: Groenen Seminar.docx URL: From eoas-seminar at lists.fsu.edu Mon Mar 25 10:05:11 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Mon, 25 Mar 2019 14:05:11 +0000 Subject: [Eoas-seminar] REMINDER: Meteorology MS Defense for Brittany MacNamara, Thursday, March 28, 2019, 1:00 PM, LOV353 Message-ID: Meteorology Seminar Brittany MacNamara M.S. Meteorology Candidate Title: FLash characteristics and precipitation metrics of western u.s. lightning-initiated wildfires Major Professor: Dr. Henry Fuelberg Date: March 28, 2019 Time: 1:00 PM Location: Werner A. Baum Seminar Room (353 Love Building) (Please join us for refreshments served outside room 353 Love @ 12:30 PM) ABSTRACT The United States Forest Service (USFS) bases their wildfire predictions on cloud-to-ground lightning flash density thresholds greater than 5 fl km-2. High flash densities and low precipitation are often emphasized with storms since they are associated with wildfire ignitions. Yet, greater flash rates tend to occur in the areas of greatest rainfall. This study focuses on 95 lightning-initiated wildfires in the western United States during the year of 2017. Lightning data provided by the National Lightning Detection Network (NLDN) were analyzed to determine which strike(s) likely caused each fire, as well as the strikes that did not. Detailed analysis of cloud-to-ground lightning characteristics and thunderstorm characteristics such as stroke density, precipitation rate, and 24-h storm-relative QPE totals are presented. Statistical analyses using a Wilcoxon-Mann Whitney rank sum test were performed to reveal differences between lightning flashes that ignite wildfires and those that do not. Results indicate multiple-stroke negative polarity cloud-to-ground flashes dominated the fire starts. In addition, wildfires were initiated in areas with low stroke densities. Based on these tentative findings, the USFS may need to revisit their methods for wildland fire prediction. Rain rates at the locations of fire starts were 8.03 mm h-1 less than those of non-fire starting flashes, while 24-h QPE totals were 5.28 mm less. These differences were found to be statistically significant. The results of this thesis will help expand the limited knowledge of operational lightning and wildfire meteorology. However, considerable additional research is needed. Shel McGuire Florida State University Academic Program Specialist Department of Earth, Ocean, & Atmospheric Science 1017 Academic Way, 410 Love Building (Meteorology) Tallahassee, FL 32306 850-644-8582 -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: MacNamara Seminar.docx Type: application/vnd.openxmlformats-officedocument.wordprocessingml.document Size: 22572 bytes Desc: MacNamara Seminar.docx URL: From eoas-seminar at lists.fsu.edu Mon Mar 25 10:06:55 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Mon, 25 Mar 2019 14:06:55 +0000 Subject: [Eoas-seminar] REMINDER: Meteorology MS Defense for Jacob Carstens, Monday, April 1, 2019, 4:00 PM, LOV353 Message-ID: Meteorology Seminar Jacob Carstens M.S. Meteorology Candidate Title: Tropical cyclogenesis from self-aggregated convection in numerical simulations of rotating radiative-convective equilibrium Major Professor: Dr. Allison Wing Date: April 01, 2019 Time: 4:00-5:30 PM Location: Werner A. Baum Seminar Room (353 Love Building) (Please join us for refreshments served outside room 353 Love @ 3:30 PM) ABSTRACT Organized convection is of critical importance in the tropical atmosphere. Recent advances in numerical modeling have revealed that moist convection can interact with its environment to transition from a quasi-random to organized state. This phenomenon, known as convective self-aggregation, is aided by feedbacks involving clouds, water vapor, and radiation that increase the spatial variance of column-integrated frozen moist static energy. Prior studies have shown self-aggregation to take several different forms, including that of spontaneous tropical cyclogenesis in an environment of rotating radiative-convective equilibrium (RCE). This study expands upon previous work to address the processes leading to tropical cyclogenesis in this rotating RCE framework. More specifically, a 3-D, cloud-permitting numerical model is used to examine the self-aggregation of convection and potential cyclogenesis, and the background planetary vorticity is varied on an f-plane across simulations to represent a range of deep tropical and near-equatorial environments. Convection is initialized randomly in an otherwise homogeneous environment, with no background wind, precursor disturbance, or other synoptic-scale forcing. All simulations with planetary vorticity corresponding to latitudes from 10? poleward generate intense tropical cyclones, with maximum wind speeds of 80 ms-1 or above. Time to genesis and to hurricane intensity varies widely, even within a 5-member ensemble of 20? simulations, reflecting a potential degree of stochastic variability based in part on the initial random distribution of convection. Shared across this so-called "high-f" group is the emergence of a midlevel vortex in the days leading to genesis, which has dynamic and thermodynamic implications on its environment that facilitates the spinup of a low-level vortex. Tropical cyclogenesis is possible in this model even at very low values of Coriolis parameter, as far equatorward as 1?. In these experiments, convection self-aggregates into a quasi-circular cluster, which then begins to rotate and gradually strengthens into a tropical storm, aided by near-surface inflow and elevated overturning radial circulations within the aggregated cluster. Other experiments at these lower Coriolis parameters instead self-aggregate into an elongated band and fail to undergo cyclogenesis over the 100-day simulation. A large portion of this study is devoted to examining in greater detail the dynamic and thermodynamic evolution of cyclogenesis in these experiments and comparing the physical mechanisms to current theories. Shel McGuire Florida State University Academic Program Specialist Department of Earth, Ocean, & Atmospheric Science 1017 Academic Way, 410 Love Building (Meteorology) Tallahassee, FL 32306 850-644-8582 -------------- next part -------------- An HTML attachment was scrubbed... URL: From eoas-seminar at lists.fsu.edu Mon Mar 25 10:07:43 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Mon, 25 Mar 2019 14:07:43 +0000 Subject: [Eoas-seminar] REMINDER: Meteorology MS Defense for Allison Ronan, Wednesday, April 3, 2019, 1:00 PM, LOV353 Message-ID: Meteorology Seminar Allison Ronan M.S. Meteorology Candidate Title: HAVE IMPROVEMENTS IN OZONE AIR QUALITY BENEFITTED PLANTS? Major Professor: Dr. Christopher D. Holmes Date: April 3rd, 2019 Time: 1:00 PM Location: Werner A. Baum Seminar Room (353 Love Building) (Please join us for refreshments served outside room 353 Love @ 12:30 PM) ABSTRACT Surface ozone (O3) is a toxic air pollutant. In the United States and Europe, among other places, policies and technology have reduced emissions of O3 precursors the last couple decades. As a result, peak levels of O3, quantified by concentration metrics such as maximum daily average over 8 hours (MDA8), the accumulated O3 exposure over a threshold of 40 ppb (AOT40), and W126 have fallen. Influential past studies have assumed that these improvements in AOT40 and W126 imply reductions in plant injury, even though it is widely recognized that O3 flux into leaves is a better predictor of plant at damage than ambient concentration in air. Concentration metrics remain widely used because O3 concentrations measurements are more common and because concentration and flux are correlated when the variability of stomatal conductance is limited. We use a new dataset of O3 flux into plants to quantify decadal trends in the cumulative uptake of O3 (CUO) into leaf stomata for the first time. We examine 32 sites in the United States and Europe over 2005-2014 and find that the AOT40 and W126 concentration metrics decreased at 25 and 28 sites, respectively, whereas CUO increased a majority of sites (18). The divergent trends are due to stomatal control of flux, which is shaped by environmental variability. As a result, there has been no widespread, clear improvement in CUO over 2005-2014 at the sites we can assess. We use several statistical tests to show that temporal trends and variability in CUO are uncorrelated with AOT40, W126, and mean concentration (R2 [cid:image001.png at 01D4E2F2.95B50AE0] 0.15). Decreases in concentration metrics, therefore, give a falsely optimistic picture of the direction and magnitude of O3 impacts on vegetation. Because of this lack of relation between flux and concentration, flux metrics should be preferred over concentration metrics in assessments of plant injury from O3. GEOS-Chem is a 3-D global atmospheric chemistry model that uses meteorological input to simulate atmospheric composition. We evaluate the model's ability to estimate O3 deposition velocity ([cid:image002.png at 01D4E2F2.95B50AE0]) by running a simulation during the same period as the surface O3 trend analysis. By comparing monthly output of [cid:image002.png at 01D4E2F2.95B50AE0] from GEOS-Chem to our observations using the SynFlux dataset, we find that GEOS-Chem consistently underestimates [cid:image002.png at 01D4E2F2.95B50AE0] . The degree of the underestimation depends on the land class type as well as the time of year. We attempt to improve the model output by prescribing the land class type within the model to match the plant functional types at the FLUXNET sites. This did not lead to a significant improvement and in many cases, this led to a wider gap between the model and observations. We discuss possible reasons for the discrepancy between the model and observations. Improving [cid:image002.png at 01D4E2F2.95B50AE0] in the model would better estimate dry deposition of O3, which is important for simulating air quality and its impacts to humans and plants. Shel McGuire Florida State University Academic Program Specialist Department of Earth, Ocean, & Atmospheric Science 1017 Academic Way, 410 Love Building (Meteorology) Tallahassee, FL 32306 850-644-8582 -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: image001.png Type: image/png Size: 249 bytes Desc: image001.png URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: image002.png Type: image/png Size: 391 bytes Desc: image002.png URL: From eoas-seminar at lists.fsu.edu Mon Mar 25 10:08:35 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Mon, 25 Mar 2019 14:08:35 +0000 Subject: [Eoas-seminar] REMINDER: Meteorology MS Defense for Shannon Shields, Tuesday, April 2, 2019, 3:30 PM, LOV353 Message-ID: Meteorology Seminar Shannon Shields M.S. Meteorology Candidate Title: Interannual Variability of Tropical cyclone Potential Intensity and Lifetime Maximum Intensity: An Analysis of Influential Factors Major Professor: Dr. Allison Wing Date: April 2, 2019 Time: 3:30-5:00 PM Location: Werner A. Baum Seminar Room (353 Love Building) (Please join us for refreshments served outside room 353 Love @ 3:00 PM) ABSTRACT Many tropical cyclone studies have been conducted on basin-averaged potential intensity trends and the influence of sea surface temperatures (SSTs) on tropical cyclone intensity, but there is less research on along-track potential intensity (PI) and lifetime maximum intensity (referred to here as actual intensity or AI) and the factors that influence their variability. Potential intensity is a theory that predicts the maximum intensity that a tropical cyclone can achieve given certain large-scale environmental variables. Understanding interannual variability in PI and its relation to AI interannual variability is of great importance for assessing the impact of future climate conditions on tropical cyclones. Theoretically, warmer SSTs and cooler outflow temperatures would cause an increase in overall PI which in turn would lead to an increase in AI. This thesis examined the relationship between PI and AI on interannual time scales and the factors affecting PI variability: thermodynamic efficiency and air-sea enthalpy disequilibrium. Using best-track data and three reanalysis products, variability in PI and AI was examined for the North Atlantic, North Indian, South Indian, South Pacific, Eastern North Pacific, and Western North Pacific basins from 1980-2013. Overall, the Western North Pacific was the only basin that yielded high and consistently significant correlations between AI and PI. Despite the expectation from a previous study, the North Atlantic did not yield any significant correlations. Multiple tests were then conducted to determine the sensitivity of the North Atlantic correlations to different datasets and time periods. Ultimately, it was determined that the North Atlantic AI vs. PI correlation results were very dependent upon the time period and the individual years within the time period. In the comparison of all contributors, air-sea disequilibrium was the dominant contributor to PI variability. When AI variability was correlated with PI variability, disequilibrium (which is largely controlled by SSTs) was also the dominant contributor to AI variability. Although disequilibrium was the dominant factor in PI and AI interannual variability, efficiency also played a role. In fact, this study found that variances in efficiency explained 13-93% of PI interannual variability, indicating that variability in outflow temperatures (which cause much of the variability in efficiency) must be taken into account. Shel McGuire Florida State University Academic Program Specialist Department of Earth, Ocean, & Atmospheric Science 1017 Academic Way, 410 Love Building (Meteorology) Tallahassee, FL 32306 850-644-8582 -------------- next part -------------- An HTML attachment was scrubbed... URL: From eoas-seminar at lists.fsu.edu Mon Mar 25 10:33:13 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Mon, 25 Mar 2019 14:33:13 +0000 Subject: [Eoas-seminar] FW: Oceanography Dissertation Defense - Matthew Ware - 29th March CSL 1003 12pm In-Reply-To: References: Message-ID: Oceanography Seminar Matthew Ware Ph.D. Biological Oceanography Candidate Title: The effects of beach and species management actions on the nesting and incubation environment of sea turtles in the northern Gulf of Mexico Major Professor: Dr. Mariana Fuentes Defense Date: Friday, March 29 Time: 12pm Location: CSL 1003 (Chemistry Auditorium) Abstract: Sandy beaches are unique environments which offer billions of dollars-worth of ecosystem services. Management of sandy beaches tends to be anthropocentric - adjusting the coastal environment to suit the needs of human development and use. However, management actions can have important consequences for the natural functioning of these systems. Sea turtles offer an excellent case study in this balance. Understanding how the nesting and incubation environment may change under different beach- or species management actions is critical to ensuring their appropriate use in sea turtle population recovery. This dissertation investigated how two management actions affect the nesting and reproductive output of sea turtles: 1) sea turtle nest relocation including the assessment of inundation risk and 2) Leave No Trace ordinances. Though nest relocation is a common approach used to reduce losses due to inundation and other terrestrial threats, there are concerns that this strategy may alter the incubating environment of the developing embryos. In Alabama, the incubating environment between original-relocated site pairs were comparable, though relocation offered a minimal net benefit as it decreased emergence success and did not reduce the likelihood of inundation. More nests were being move than were necessary indicating additional information was needed to identify high-risk nesting sites. To better identify nests at-risk of wave exposure, a wave runup model was developed using historical beach elevation, offshore wave, and tide data. Wave runup modeling proved effective at identifying washed over nesting sites (83%). An updated digital elevation model (DEM) was not necessary as a time-averaged DEM performed better than, or comparable to, those using the most recent LiDAR survey. However, a more complete understanding of sea turtle embryonic tolerance to inundation would improve high-risk site identification. HOBO U20L-04 water level loggers were tested in situ to evaluate their potential to provide this inundation tolerance information versus existing PVC-based equipment. The HOBO loggers provided high resolution observations of inundation frequency, duration, and severity; however, their high cost will limit the scale of their deployment. Sea turtle population recovery is predicated not just on our ability to reduce losses of developing embryos, but on the continued availability of suitable nesting habitat itself. Leave No Trace ordinances are increasingly being used to combat the issue of marine debris including abandoned beach equipment. The ordinances had mixed success - though obstructed crawls did decline after the ordinance in Gulf Shores and Orange Beach, the presence of an obstruction did not influence a turtle's decision to nest and nesting success declined after the ordinance across the study area due to natural variation. These two management actions appeared to have only small effects on sea turtle hatchling production and population growth rates in the northern Gulf of Mexico. But as charismatic megafauna and valuable ecosystem service providers, their continued conservation based on the provision of suitable environmental conditions serves as an important example of the need to balance anthropocentric coastal zone management with ecosystem function. -------------- next part -------------- An HTML attachment was scrubbed... URL: From eoas-seminar at lists.fsu.edu Mon Mar 25 10:34:37 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Mon, 25 Mar 2019 14:34:37 +0000 Subject: [Eoas-seminar] Geology Thesis Defense - Terryl Bandy - April 8, 9am - 104CAR Message-ID: Title: Environmental Controls on Organic Carbon Productivity in the Midland Basin Major Professor: Jeremy Owens -------------- next part -------------- An HTML attachment was scrubbed... URL: From eoas-seminar at lists.fsu.edu Mon Mar 25 11:26:37 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Mon, 25 Mar 2019 15:26:37 +0000 Subject: [Eoas-seminar] PhD dissertation defense, Wm. Brian Wells, Friday, 29 March 2019, 2 pm Baum Seminar Room (353 Love Building) Message-ID: PhD dissertation defense, Wm. Brian Wells, Friday, 29 March 2019, 2 pm Baum Seminar Room (353 Love Building) "Degradation of Deepwater Horizon oil buried in beach, shelf and slope sediments of the northeastern Gulf of Mexico" Markus Huettel Department of Earth, Ocean and Atmospheric Science Florida State University 117 N Woodward Ave. P.O. Box 3064320 Tallahassee, Florida 32306-4320 USA Phone: (850) 645-1394 Fax: (850) 644-2581 Email: mhuettel at fsu.edu Website: http://myweb.fsu.edu/mhuettel/ -------------- next part -------------- A non-text attachment was scrubbed... Name: Brian Wells.pdf Type: application/pdf Size: 331719 bytes Desc: Brian Wells.pdf URL: From eoas-seminar at lists.fsu.edu Mon Mar 25 12:34:24 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Mon, 25 Mar 2019 12:34:24 -0400 Subject: [Eoas-seminar] BS defense Message-ID: Mackenzie Baysinger Correcting for mineral interference in organic samples when using FTIR spectroscopy Thursday, March 28, @ 3:30 pm OSB 327 -- jeff chanton Department of Earth, Ocean and Atmospheric Science, EOAS, Rm 404 Love Bldg Mail Code 4520 Florida State University 1017 Academic Way Tallahassee, FL 32306 -4520 850-644-7493 "We must forcefully reject the notion that our being created in God's image and given dominion over the earth justifies absolute domination over other creatures. The Bible has no place for a tyrannical anthropocentricism." Pope Francis. The ocean is a desert with its life underground and the perfect disguise above. America, 1972 Germanicus?s way was always to refuse to think evil of any person until positive proof of such evil should be forced on him, and, on the contrary, to credit everyone with the highest motives. This extreme simplicity was generally of service to him. Most people with whom he came in contact were flattered by his high estimate of their moral character and tended in their dealing with him to live up to it. If he were ever to find himself at the mercy of a downright wicked character, this generosity of heart would of course be his undoing; but on the other hand, if any man had good in him Germanicus always seemed to bring it out. Robert Graves. From I, Claudius, the biography of Tiberius Claudius -------------- next part -------------- An HTML attachment was scrubbed... URL: From eoas-seminar at lists.fsu.edu Tue Mar 26 11:21:30 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Tue, 26 Mar 2019 15:21:30 +0000 Subject: [Eoas-seminar] EOAS Colloquium this Fri at 3:30 in CAR 101 Message-ID: Hope you had a great break! Our speaker this week is Dr Tracey Sutton from Nova Southeastern University http://sutton.deependconsortium.org/ His seminar will be at 3:30 on Friday in CAR 101. The title of his talk is: Ecosystem dynamics of the deep-pelagic Gulf of Mexico: fauna, physics, and future Dr. Sutton is here all day Friday and has a few available slots left to meet with people. Please email abacotaylor at fsu.edu if you would like to talk with him. -------------- next part -------------- An HTML attachment was scrubbed... URL: From eoas-seminar at lists.fsu.edu Wed Mar 27 15:59:07 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Wed, 27 Mar 2019 19:59:07 +0000 Subject: [Eoas-seminar] Last call to meet with speaker In-Reply-To: References: Message-ID: Colleagues, We have only 2 open time slots left to meet with the speaker on Friday. Please let me know asap if you are interested. Thanks, Amy On 3/26/19 11:21 AM, eoas-seminar at lists.fsu.edu wrote: Hope you had a great break! Our speaker this week is Dr Tracey Sutton from Nova Southeastern University http://sutton.deependconsortium.org/ His seminar will be at 3:30 on Friday in CAR 101. The title of his talk is: Ecosystem dynamics of the deep-pelagic Gulf of Mexico: fauna, physics, and future Dr. Sutton is here all day Friday and has a few available slots left to meet with people. Please email abacotaylor at fsu.edu if you would like to talk with him. -- Amy Baco-Taylor, PhD Associate Professor Earth, Ocean, and Atmospheric Sciences Florida State University (850) 645-1547 abacotaylor at fsu.edu -------------- next part -------------- An HTML attachment was scrubbed... URL: From eoas-seminar at lists.fsu.edu Thu Mar 28 09:02:45 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Thu, 28 Mar 2019 13:02:45 +0000 Subject: [Eoas-seminar] REMINDER: Meteorology MS Defense for Brittany MacNamara, Thursday, March 28, 2019, 1:00 PM, LOV353 Message-ID: Meteorology Seminar Brittany MacNamara M.S. Meteorology Candidate Title: FLash characteristics and precipitation metrics of western u.s. lightning-initiated wildfires Major Professor: Dr. Henry Fuelberg Date: March 28, 2019 Time: 1:00 PM Location: Werner A. Baum Seminar Room (353 Love Building) (Please join us for refreshments served outside room 353 Love @ 12:30 PM) ABSTRACT The United States Forest Service (USFS) bases their wildfire predictions on cloud-to-ground lightning flash density thresholds greater than 5 fl km-2. High flash densities and low precipitation are often emphasized with storms since they are associated with wildfire ignitions. Yet, greater flash rates tend to occur in the areas of greatest rainfall. This study focuses on 95 lightning-initiated wildfires in the western United States during the year of 2017. Lightning data provided by the National Lightning Detection Network (NLDN) were analyzed to determine which strike(s) likely caused each fire, as well as the strikes that did not. Detailed analysis of cloud-to-ground lightning characteristics and thunderstorm characteristics such as stroke density, precipitation rate, and 24-h storm-relative QPE totals are presented. Statistical analyses using a Wilcoxon-Mann Whitney rank sum test were performed to reveal differences between lightning flashes that ignite wildfires and those that do not. Results indicate multiple-stroke negative polarity cloud-to-ground flashes dominated the fire starts. In addition, wildfires were initiated in areas with low stroke densities. Based on these tentative findings, the USFS may need to revisit their methods for wildland fire prediction. Rain rates at the locations of fire starts were 8.03 mm h-1 less than those of non-fire starting flashes, while 24-h QPE totals were 5.28 mm less. These differences were found to be statistically significant. The results of this thesis will help expand the limited knowledge of operational lightning and wildfire meteorology. However, considerable additional research is needed. Shel McGuire Florida State University Academic Program Specialist Department of Earth, Ocean, & Atmospheric Science 1017 Academic Way, 410 Love Building (Meteorology) Tallahassee, FL 32306 850-644-8582 -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: MacNamara Seminar.docx Type: application/vnd.openxmlformats-officedocument.wordprocessingml.document Size: 22572 bytes Desc: MacNamara Seminar.docx URL: From eoas-seminar at lists.fsu.edu Thu Mar 28 09:03:23 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Thu, 28 Mar 2019 13:03:23 +0000 Subject: [Eoas-seminar] REMINDER: Meteorology PhD Defense for Danielle Groenen, Thursday, March 28, 2019, 3:30 PM, LOV353 Message-ID: Meteorology Seminar Danielle Groenen PhD Meteorology Candidate Title: Diagnosing the Atmospheric Phenomena Associated with the Onset and Demise of the Mesoamerican Rainy Season Major Professor: Dr. Mark Bourassa Date: Thursday, March 28, 2019 Time: 3:30 PM Location: Werner A. Baum Seminar Room (353 Love Building) (Please join us for refreshments served outside room 353 Love @ 3:00 PM) ABSTRACT Mexico and Central America (Mesoamerica) are situated in a complex and unique geographical position with the Caribbean Sea to the East and the tropical Eastern Pacific Ocean to the West. The weather patterns of this region are driven by winds, temperatures, moisture, and orography of several mountain ranges. The Mesoamerican Rainy Season has traditionally been defined as May through November each year, and past studies often use monthly climatologies when analyzing the phenomenology associated with the rainfall. However, key crops grown in Mesoamerica such as bananas, coffee, corn, cacao, and rice require more detail on a daily-to weekly temporal scale. This study finds the dates of the onset and demise of rainfall regimes on a specific day using NASA's Tropical Rainfall Measuring Mission (TRMM) rainfall for years 1998-2012, area-averaged over land. Using NASA's MERRA-2 Reanalysis data, we also look at the phenomenology of the triggers of the rainy season onset and demise on the daily time-scale instead of the monthly scales used by previous studies. We find that the Mesoamerican Rainy Season can be distinguished into two parts: the Early Spring Rainfall (ESR) associated with light rains and the Late Spring Rainfall (LSR) associated with heavy rains. Two algorithms are used to obtain these rainy season distinctions. A new algorithm was developed during this study, to calculate when the rainfall first starts to increase. The daily cumulative anomalies of rainfall are compared to the climatological rainfall to find the time of onset of the heavy rains. To better understand the phenomenology associated with the timing of the rainfall, we look at the monsoon trough, moisture flux convergence, and the weakening/strengthening of the winds associated with the Caribbean Low-Level Jet and Panama Jet. The light rainfall begins, on average, in mid-March, approximately one month after the peak of the winter Caribbean Low-Level Jet and the Panama Jet. The ramp-up between the light rains and heavy rains is associated with a significant weakening of both jets and the northward progression of a monsoon trough off the western coast of Central America. The heavy rains begin, on average, in mid-May, and are associated with the timing when the Panama Jet goes to near zero magnitude. We find the rainfall onsets materialize first, which then change the wind patterns and regional moisture convergence. The rainfall onsets are followed by a positive total moisture flux convergence in the entire domain. At the demise of the rainfall, approximately in mid-November, the Panama Jet strengthens again and the total moisture flux convergence decreases significantly. The results of this study have positive implications in agriculture and water resources for Mesoamerica, as this information may help resource managers better plan and adapt to climate variability. Shel McGuire Florida State University Academic Program Specialist Department of Earth, Ocean, & Atmospheric Science 1017 Academic Way, 410 Love Building (Meteorology) Tallahassee, FL 32306 850-644-8582 -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: Groenen Seminar.docx Type: application/vnd.openxmlformats-officedocument.wordprocessingml.document Size: 22711 bytes Desc: Groenen Seminar.docx URL: From eoas-seminar at lists.fsu.edu Thu Mar 28 09:31:35 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Thu, 28 Mar 2019 13:31:35 +0000 Subject: [Eoas-seminar] Reminder: Oceanography Thesis Defense - Rachel Petet - March 28, 10am - CSL1005 Message-ID: Oceanography Seminar Rachel Petet M.S. Biological Oceanography Candidate Title: Impacts of microbial community structure on denitrification rates in the rhizosphere of J. roemerianus and S. alterniflora collocated in a Gulf of Mexico saltwater marsh Major Professor: Dr. Olivia U. Mason Date: March 28rd, 2019 Time: 10:00 AM Location: Chemistry 1005 (CSL 1005) ABSTRACT Marshes are particularly important ecosystems, providing long-term soil carbon storage, flood protection and nutrient filtration. Nutrient filtering, specifically nitrate removal, is largely the result of belowground microbially mediated denitrification. Denitrification rates differ in Spartina alterniflora and Juncus roemerianus patches but determining how the associated microbial communities contribute to these differences is challenged by the inherent physicochemical variability in the belowground of plants at different elevations in the marsh. Here we had a unique opportunity to evaluate denitrification rates and the belowground microbial community in J. roemerianus and S. alterniflora collocated at the same elevation, thus experiencing the same inundation cycles, in a saltwater marsh. To determine denitrification rates sediment slurry incubations (15N-nitrate) were used. The microbial community structure was determined using "iTag" sequencing of 16S rRNA gene amplicons. Slurry experiments revealed that denitrification rates were consistently higher in J. roemerianus. Analysis of 16S rRNA exact amplicon sequence variants (ASVs) showed that the microbial communities were similar in both plant types, although significant oscillations in abundance of some ASVs was observed. To link the rate and microbial community data, Random Forest Modeling (RFM) was used to determine if specific microbes could be accurate predictors of higher or lower denitrification rates. RFM identified ASVs classified as Deltaproteobacteria; Desulfobacteraceae and Chloroflexi; Anaerolineaceae as the most important predictors of denitrification rates. These microbial predictors were also identified as core members of the rhizosphere of both plants. Desulfobacteraceae, indicates higher denitrification rates, while Anaerolineaceae points towards lower rates of nitrate removal. Desulfobacteraceae are known sulfate reducers, however some have been shown to utilize both nitrate and sulfate to grow chemolithoautotrophically by coupling sulfide oxidation to dissimilatory nitrate reduction. In fact, this pathway was identified in a complimentary metagenomic dataset. Collectively, our data revealed that J. roemerianus promoted greater belowground nitrate removal compared to S. alterniflora which may result from different plant characteristics that lead to oscillations in the abundance of core members of the microbial community that can serve as predictors of denitrification rates and that this reaction may be mediated by previously unsuspected sulfate reducing bacteria in our saltmarsh ecosystem -------------- next part -------------- An HTML attachment was scrubbed... URL: From eoas-seminar at lists.fsu.edu Fri Mar 29 09:31:24 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Fri, 29 Mar 2019 13:31:24 +0000 Subject: [Eoas-seminar] Reminder: Oceanography Dissertation Defense - Matthew Ware - 29th March CSL 1003 12pm Message-ID: Oceanography Seminar Matthew Ware Ph.D. Biological Oceanography Candidate Title: The effects of beach and species management actions on the nesting and incubation environment of sea turtles in the northern Gulf of Mexico Major Professor: Dr. Mariana Fuentes Defense Date: Friday, March 29 Time: 12pm Location: CSL 1003 (Chemistry Auditorium) Abstract: Sandy beaches are unique environments which offer billions of dollars-worth of ecosystem services. Management of sandy beaches tends to be anthropocentric - adjusting the coastal environment to suit the needs of human development and use. However, management actions can have important consequences for the natural functioning of these systems. Sea turtles offer an excellent case study in this balance. Understanding how the nesting and incubation environment may change under different beach- or species management actions is critical to ensuring their appropriate use in sea turtle population recovery. This dissertation investigated how two management actions affect the nesting and reproductive output of sea turtles: 1) sea turtle nest relocation including the assessment of inundation risk and 2) Leave No Trace ordinances. Though nest relocation is a common approach used to reduce losses due to inundation and other terrestrial threats, there are concerns that this strategy may alter the incubating environment of the developing embryos. In Alabama, the incubating environment between original-relocated site pairs were comparable, though relocation offered a minimal net benefit as it decreased emergence success and did not reduce the likelihood of inundation. More nests were being move than were necessary indicating additional information was needed to identify high-risk nesting sites. To better identify nests at-risk of wave exposure, a wave runup model was developed using historical beach elevation, offshore wave, and tide data. Wave runup modeling proved effective at identifying washed over nesting sites (83%). An updated digital elevation model (DEM) was not necessary as a time-averaged DEM performed better than, or comparable to, those using the most recent LiDAR survey. However, a more complete understanding of sea turtle embryonic tolerance to inundation would improve high-risk site identification. HOBO U20L-04 water level loggers were tested in situ to evaluate their potential to provide this inundation tolerance information versus existing PVC-based equipment. The HOBO loggers provided high resolution observations of inundation frequency, duration, and severity; however, their high cost will limit the scale of their deployment. Sea turtle population recovery is predicated not just on our ability to reduce losses of developing embryos, but on the continued availability of suitable nesting habitat itself. Leave No Trace ordinances are increasingly being used to combat the issue of marine debris including abandoned beach equipment. The ordinances had mixed success - though obstructed crawls did decline after the ordinance in Gulf Shores and Orange Beach, the presence of an obstruction did not influence a turtle's decision to nest and nesting success declined after the ordinance across the study area due to natural variation. These two management actions appeared to have only small effects on sea turtle hatchling production and population growth rates in the northern Gulf of Mexico. But as charismatic megafauna and valuable ecosystem service providers, their continued conservation based on the provision of suitable environmental conditions serves as an important example of the need to balance anthropocentric coastal zone management with ecosystem function. -------------- next part -------------- An HTML attachment was scrubbed... URL: From eoas-seminar at lists.fsu.edu Fri Mar 29 09:34:24 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Fri, 29 Mar 2019 13:34:24 +0000 Subject: [Eoas-seminar] Reminder: Oceanography dissertation defense, Wm. Brian Wells, Friday, 29 March 2019, 2 pm Baum Seminar Room (353 Love Building) Message-ID: PhD dissertation defense, Wm. Brian Wells, Friday, 29 March 2019, 2 pm Baum Seminar Room (353 Love Building) "Degradation of Deepwater Horizon oil buried in beach, shelf and slope sediments of the northeastern Gulf of Mexico" Markus Huettel Department of Earth, Ocean and Atmospheric Science Florida State University 117 N Woodward Ave. P.O. Box 3064320 Tallahassee, Florida 32306-4320 USA Phone: (850) 645-1394 Fax: (850) 644-2581 Email: mhuettel at fsu.edu Website: http://myweb.fsu.edu/mhuettel/ -------------- next part -------------- A non-text attachment was scrubbed... Name: Brian Wells.pdf Type: application/pdf Size: 331719 bytes Desc: Brian Wells.pdf URL: From eoas-seminar at lists.fsu.edu Fri Mar 29 10:03:24 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Fri, 29 Mar 2019 14:03:24 +0000 Subject: [Eoas-seminar] Reminder Seminar today 3:30 in CAR 101 In-Reply-To: References: Message-ID: Our speaker this week is Dr Tracey Sutton from Nova Southeastern University http://sutton.deependconsortium.org/ His seminar will be at 3:30 TODAY in CAR 101. The title of his talk is: Ecosystem dynamics of the deep-pelagic Gulf of Mexico: fauna, physics, and future -------------- next part -------------- An HTML attachment was scrubbed... URL: