From eoas-seminar at lists.fsu.edu Thu Oct 3 09:10:54 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Thu, 3 Oct 2019 13:10:54 +0000 Subject: [Eoas-seminar] Fw: MET Seminar, Oct. 3 In-Reply-To: References: Message-ID: Hi all, Just a reminder that at 3:30 PM today we have a MET seminar at LOV 353. Today's speaker is Prof. Hu. Also, I have attached another flyer for the MET seminar series. Our next week's speaker will be Prof. Esther Mullens. Look forward to meeting you. Cheers, Zhaohua ________________________________ From: Zhaohua Wu Sent: Thursday, September 26, 2019 9:44 AM To: eoas-seminar at lists.fsu.edu ; info at coaps.fsu.edu Cc: Xiaoming Hu Subject: MET Seminar, Oct. 3 Hi All, In the coming Thursday (Oct. 3), we will have the first MET seminar in this academic year at regular seminar time and location (3:30 PM, LOV 353) in which Prof. Hu will discuss model projected global warming. The title and abstract of her talk are (also see the attached seminar announcement flyer) Title: What are the main sources for the spread of climate model warming projection? Abstract: Climate models forced by increasing greenhouse gas concentrations unanimously project a long-term warming of Earth?s surface. The magnitude of this warming diverges substantially between models, which is termed as the inter-model warming projection spread (WPS). Cloud feedback has been postulated as the main cause of the large inter-model WPS. We examine the global warming projection under the RCP8.5 scenario reported in the Intergovernmental Panel on Climate Change (IPCC) fifth assessment report. We find that the inter-model spreads of surface albedo and water vapor feedbacks are the key contributors to the inter-model WPS. Surface turbulent sensible and latent heat flux feedbacks cancel out part of the inter-model spreads surface albedo and water vapor feedbacks, and therefore act to suppress the inter-model WPS. Despite of its large amplitude, the inter-model spread of cloud feedbacks exhibit little correlation with the inter-model WPS. Because different models exhibit different combinations of cancellations between cloud feedbacks and other feedback processes, the impact of the inter-model spread of cloud feedbacks does not play a major role in causing the inter-model WPS. The following is the list of this semester's MET seminar series: Date Speaker Title Oct. 3, 2019 Xiaoming Hu What are the main sources for the spread of climate model warming projection? Oct. 10, 2019 Esther Mullens The past, present, and future of extreme precipitation in the South Central U.S. Oct. 17, 2019 Zhaohua Wu Conditional Instability of the Second Kind: A Dead End or An Old and New Path Oct. 24, 2019 MET Faculty Meeting MET Faculty Meeting - No Seminar Oct. 31, 2019 Brian Haynes Thesis Defense Nov. 7, 2019 Nirupam Karmakar TBD Nov. 14, 2019 Allison Wing The role of radiative-convective feedbacks in tropical cyclone formation in numerical simulations Nov. 21, 2019 Bobby West TBD Nov. 28, 2019 Thanksgiving Thanksgiving - No Seminar Dec. 5, 2019 Sweta Das Thesis Defense Look forward to meeting you in the seminar room. Cheers, Zhaohua -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: MET_Seminar_Flyer_Hu.pdf Type: application/pdf Size: 987752 bytes Desc: MET_Seminar_Flyer_Hu.pdf URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: MET_Seminar_Flyer_Mullens.pdf Type: application/pdf Size: 952665 bytes Desc: MET_Seminar_Flyer_Mullens.pdf URL: From eoas-seminar at lists.fsu.edu Thu Oct 3 22:38:01 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Fri, 4 Oct 2019 02:38:01 +0000 Subject: [Eoas-seminar] EOAS Colloquium, Friday, Oct. 4, 3:30 PM in CAR 101. Message-ID: Hi all, Please join us for our next speaker in the Fall EOAS Colloquium series, this Friday Oct. 4 at 3:30 in CAR 101. Dr. Nick Moore, Assoc. Prof., Mathematics, FSU Title: Experiments and theory for anomalous waves induced by abrupt changes in topography Abstract: I will discuss both laboratory experiments and a newly developed theory for randomized surface waves propagating over variable bathymetry. The experiments show that an abrupt depth change can qualitatively alter wave statistics, transforming an initially Gaussian wave field into a highly skewed one. In our experiments, the probability of a rogue wave can increase by a factor of 50 compared to what would be expected from normal statistics. I will discuss a theoretical framework based on dynamical and statistical analysis of the truncated KdV equations. This theory accurately captures many key features of the experiments, such as the skewed outgoing wave distributions and the associated excitation of higher frequencies in the spectrum. -------------- next part -------------- An HTML attachment was scrubbed... URL: From eoas-seminar at lists.fsu.edu Tue Oct 8 10:48:51 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Tue, 8 Oct 2019 14:48:51 +0000 Subject: [Eoas-seminar] EOAS Colloquium, Friday, Oct. 11, 3:30 PM in CAR 101 Message-ID: Hi all, Please join us for our next speaker in the Fall EOAS Colloquium series, this Friday Oct. 11 at 3:30 in CAR 101. Dr. Daniel Ohnemus, Skidaway Institute of Oceanography, University of Georgia Title: Exposing ?Latent? Scavenged Particulate Phases in the Oceans Abstract: The last decade has seen a rapid increase in the number of high-resolution, multi-elemental datasets for particulate (and dissolved) concentrations in the oceans, largely through the work of the international GEOTRACES program. Our conceptual framework for marine trace element cycling, especially in the open ocean, often remains simplified as the production and remineralization of phytoplankton biomass. Many bioactive trace element cycles are primarily considered, often literally, an extension of traditional Redfield macronutrient ratios. The identities and internal behaviors of other authigenic (scavenged) phases that form in the oceans remain hidden within these multi-element datasets. In this talk I demonstrate how several statistical techniques?and a few visual ones?can reveal these latent phases in datasets from contrasting regions. We find that no bioactive element behaves identically to the macronutrient P, and that the cycles of many bioactive trace elements are dominated by strong, and potentially predictable, internal authigenic cycles. -------------- next part -------------- An HTML attachment was scrubbed... URL: From eoas-seminar at lists.fsu.edu Thu Oct 10 09:41:27 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Thu, 10 Oct 2019 13:41:27 +0000 Subject: [Eoas-seminar] Reminder of today's seminar and next week's seminar Message-ID: Hi all, Just a reminder that at 3:30 PM today we have a MET seminar at LOV 353. Today's speaker will be Prof. Esther Mullens of the University of Florida. Also, I have attached another flyer for the MET seminar series. Our next week's speaker will be Prof. Zhaohua Wu of FSU. Look forward to meeting you. Cheers, Zhaohua -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: MET_Seminar_Flyer_Mullens.pdf Type: application/pdf Size: 952665 bytes Desc: MET_Seminar_Flyer_Mullens.pdf URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: MET_Seminar_Flyer_Wu.pdf Type: application/pdf Size: 980585 bytes Desc: MET_Seminar_Flyer_Wu.pdf URL: From eoas-seminar at lists.fsu.edu Fri Oct 11 00:21:08 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Fri, 11 Oct 2019 04:21:08 +0000 Subject: [Eoas-seminar] EOAS Colloquium, Friday, Oct. 11, 3:30 PM in CAR 101 Message-ID: Hi all, Please join us for our next speaker in the Fall EOAS Colloquium series, this Friday Oct. 11 at 3:30 in CAR 101. Dr. Daniel Ohnemus, Skidaway Institute of Oceanography, University of Georgia Title: Exposing ?Latent? Scavenged Particulate Phases in the Oceans Abstract: The last decade has seen a rapid increase in the number of high-resolution, multi-elemental datasets for particulate (and dissolved) concentrations in the oceans, largely through the work of the international GEOTRACES program. Our conceptual framework for marine trace element cycling, especially in the open ocean, often remains simplified as the production and remineralization of phytoplankton biomass. Many bioactive trace element cycles are primarily considered, often literally, an extension of traditional Redfield macronutrient ratios. The identities and internal behaviors of other authigenic (scavenged) phases that form in the oceans remain hidden within these multi-element datasets. In this talk I demonstrate how several statistical techniques?and a few visual ones?can reveal these latent phases in datasets from contrasting regions. We find that no bioactive element behaves identically to the macronutrient P, and that the cycles of many bioactive trace elements are dominated by strong, and potentially predictable, internal authigenic cycles. -------------- next part -------------- An HTML attachment was scrubbed... URL: From eoas-seminar at lists.fsu.edu Sun Oct 13 17:14:41 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Sun, 13 Oct 2019 21:14:41 +0000 Subject: [Eoas-seminar] Next EOAS Colloquium on Nov 1 Message-ID: There will be no EOAS colloquium this week because of the Dept Faculty meeting There will be no EOAS colloquium on Oct 25th either because the university is closed that day. Our next EOAS colloquium speaker will be Isla Simpson on Nov 1. From eoas-seminar at lists.fsu.edu Mon Oct 14 17:36:09 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Mon, 14 Oct 2019 21:36:09 +0000 Subject: [Eoas-seminar] Geology PhD defense - Farman Ullah - Oct 28, 12pm - 104CAR Message-ID: Title: Structural Architecture and Jurassic to Eocene Chrono-Stratigraphic Evolution of the North Sulaiman Range, Mughal Kot Gorge, Pakistan. Major Professor: Jim Tull -------------- next part -------------- An HTML attachment was scrubbed... URL: From eoas-seminar at lists.fsu.edu Wed Oct 16 16:13:25 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Wed, 16 Oct 2019 20:13:25 +0000 Subject: [Eoas-seminar] Meteorology PhD Defense for Bachir Annane, October 30, 3:00 PM, Love 353 Message-ID: Meteorology Seminar Bachir Annane PhD Meteorology Candidate Title: HWRF ANALYSIS AND FORECAST IMPACT OF CYGNSS OBSERVATIONS ASSIMILATED AS SCALAR WIND SPEEDS AND AS VAM WIND VECTORS Major Professors: Dr. Guosheng Liu and Dr. Ruby Krishnamurti Date: October 30, 2019 Time: 3:00 PM Location: Werner A. Baum Seminar Room (353 Love Building) (Please join us for refreshments served outside room 353 Love @ 2:30 PM) ABSTRACT After decades of focused research into tropical cyclone (TC) dynamics and evolution, operational centers are now able to predict TC track out to a lead time of five days with a high degree of accuracy. However, during this time, forecast skill for TC intensity has not kept the same pace. There are likely many reasons for this slowing improvement in TC intensity forecasts, but the one that is cited often in the community is a lack of frequent and accurate observations of winds in the inner core of TCs. Specifically, current satellite observing systems are unable to penetrate through heavy rainfall, and in situ measurements by aircraft and dropsondes are limited in space and time. The paucity of observations of surface wind speeds in the most dynamically active portion of a TC leads to (1) inaccuracies in the initial conditions used in subsequent model forecasts and (2) insufficient information for evaluating parameterizations of convection and surface fluxes. The NASA Cyclone Global Navigation Satellite System (CYGNSS) mission is designed to address these shortcomings by providing more accurate and timely observations of surface winds in all precipitation conditions. Eight micro-satellites launched in December 2016 (CYGNSS), providing an unprecedented opportunity to obtain ocean surface wind at increased revisit frequency compared to polar-orbiting satellites. Release 2.1 of the CYGNSS data contain improved wind speed quality and can be used to run data impact studies for the cases where the operational center had a weak intensity forecast. This study explores the expected benefits of this retrieved data to numerical simulations of tropical cyclones using two different data assimilation methods within the experimental framework of Observing System Simulation Experiments (OSSE) and Observing System Experiments (OSE). The goals of this study are three-fold: first, investigate the potential for CYGNSS to improve analyses and forecasts of tropical cyclones in an OSSE framework (pre-Launch); second, application of the variational analysis method (VAM) method on the CYGNSS data; third, evaluate the actual influence of assimilating CYGNSS data into NOAA's operational hurricane model (Post-Launch). >From a highly detailed and realistic hurricane nature run (NR), CYGNSS winds were simulated with error characteristics that are expected to occur in reality, and directional information is added using a two dimensional VAM for near-surface vector winds that blends simulated CYGNSS wind speeds with an a priori background vector wind field at 6-h analysis times. The OSSE system makes use of NOAA's Hurricane Weather and Research Forecast (HWRF) model and Gridpoint Statistical Interpolation (GSI) data assimilation system in a configuration that was operational in 2012. CYGNSS winds were assimilated as scalar wind speeds and as wind vectors determined by a variational analysis method. Both forms of wind information had positive impacts on the short-term HWRF forecasts, as shown by key storm and domain metrics. Data assimilation cycle intervals of 1, 3, and 6 hours were tested, and the 3-h impacts were consistently best. The OSE quantifies the impact of assimilating both CYGNSS retrieved wind speed and derived CYGNSS wind vectors in tropical cyclone Michael (2018) on 6-hourly analyses and 5-day forecasts, using the 2019 version of the operational HWRF model. It is found that the assimilation of CYGNSS data results in improved track, intensity, and structure forecasts for both retrieved and derived CYGNSS data, implying the potential benefits of using such data for future research and operational applications. 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 Thu Oct 17 09:09:02 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Thu, 17 Oct 2019 13:09:02 +0000 Subject: [Eoas-seminar] (no subject) Message-ID: Hi all, Just a reminder that at 3:30 PM today we have a MET seminar at LOV 353. Today's speaker will be Prof. Zhaohua Wu of EOAS. The title and the abstract of his talk can be found in the attached fly. It is also remind that we did not schedule a MET seminar for Thursday, Oct. 24. Look forward to meeting you. Cheers, Zhaohua -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: MET_Seminar_Flyer_Wu.pdf Type: application/pdf Size: 980585 bytes Desc: MET_Seminar_Flyer_Wu.pdf URL: From eoas-seminar at lists.fsu.edu Fri Oct 18 15:33:37 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Fri, 18 Oct 2019 19:33:37 +0000 Subject: [Eoas-seminar] Meteorology MS Defense for Brian Haynes, October 31, 3:30 PM, Love 353 Message-ID: Meteorology Seminar Brian Haynes MS Meteorology Candidate Title: Climate Variability of the Arctic from an Isentropic Potential Vorticity Perspective Major Professor: Dr. Eric Chassignet Date: October 31, 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 The persistence of the positive phase of the Arctic Ocean Oscillation (AOO) during the last two decades is examined by invoking potential vorticity dynamics in a warming Arctic climate to describe tendencies of atmospheric forcing at the Arctic boundary layer. Positive indices of the AOO are indicative of an anti-cyclonic wind stress being imparted at the ice-ocean surface in the Beaufort Sea, a pattern typical during Arctic winters, throughout most of a given year. An IPV framework used to relate increasing Arctic ambient temperatures and sea ice loss with the AOO is achieved by analyzing isentropic output from a blend of the Climate Forecast System Reanalysis (CFSR) and Climate Forecast System version 2 (CFSv2) reanalysis data, as well as surface heat flux output from the same dataset in order to draw conclusions about how diabatic effects may annihilate low-level potential vorticity and reinforce atmospheric stability. These analyses were sectioned into a focus of the inherent differences between positive and negative (cyclonic-regime) phases of the AOO over the time period spanning 1979-2017, with a closer examination pertaining IPV advection and baroclinic development during differing AOO cycles in the Arctic on synoptic timescales. The trends and patterns in Arctic IPV are compared with Arctic sea ice extent and linked to warming by a reduction in the meridional IPV gradient, which in turn weakens the zonal flow and allows for the meridional advection of lower potential vorticity into the region. Baroclinic development of these disturbances vary in location and with season and can amplify ridging downstream, enhancing stationary waves. This implies not only a connection between reduced IPV and the negative phase of the Arctic Oscillation (AO), but that the weakened IPV gradient may allow for transmittance of heat and momentum to the upper levels of the atmosphere, supporting previous studies regarding the impacts that wave-mean flow interaction has on the warming tropopause. These findings demonstrate that the ice melt season, specifically summer and autumn, has an important role in determining the AOO cycle and are supported by IPV theory. 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 Oct 18 15:37:43 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Fri, 18 Oct 2019 19:37:43 +0000 Subject: [Eoas-seminar] Meteorology PhD defense for Levi Cowan, November 1, 2:00 PM, Love 353 Message-ID: Meteorology Seminar Levi Cowan PhD Meteorology Candidate Title: ATLANTIC TROPICAL CYCLONE INTERACTIONS WITH UPPER TROPOSPHERIC TROUGHS AND JETS: IDENTIFICATION, CLIMATOLOGY, AND MODULATION OF TROPICAL CYCLONE INTENSITY Major Professor: Dr. Robert Hart Date: November 1, 2019 Time: 2:00 PM Location: Werner A. Baum Seminar Room (353 Love Building) (Please join us for refreshments served outside room 353 Love @ 1:30 PM) ABSTRACT Interactions of Atlantic tropical cyclones (TCs) with upper tropospheric flow are identified in 37 years of ERA-Interim reanalysis data and analyzed from multiple perspectives. Upper tropospheric troughs are identified in a more comprehensive way than past methodologies, targeting features on the dynamic tropopause to reduce exclusivity of feature selection and sensitivity to the background environment. As a unique way of characterizing and subsetting environmental flow, upper tropospheric jets are identified in 200-hPa wind fields within 3000 km of TCs using a robust, objective algorithm. The climatology of the resulting dataset of jet axes is explored through various means, including an objective clustering technique, which yielded seven statistically distinct groups of jets associated with recognizable flow patterns near TCs. The mean impact of TC outflow on adjacent jets is also quantified, with along-jet acceleration downstream of the TC found to be nearly ubiquitous across the Atlantic basin, though modulated strongly by the geographically varying background state. The influence of nearby upper tropospheric troughs and jets on TC intensity is also assessed through a variety of approaches. In order to minimize systematic sampling biases when quantifying this impact, a spatially varying climatology of TC intensification rate is developed using a second-order, generalized least squares regression model, allowing TC intensity responses to external forcing to be evaluated as departures from their expected value. Both troughs and jets are found to be net negative influences on TC intensity, on average, primarily due to increasing vertical shear with proximity to the vortex. Differences between rapidly intensifying (RI) and rapidly weakening (RW) cases during TC-trough-jet interactions depend not only on shear, but on dynamic forcing imposed by baroclinic processes and eddy momentum fluxes that can counter the influence of shear. Intensifying cases are primarily associated with jets that approach the poleward side of the TC and possess entrance regions that amplify over time, increasing dynamic forcing for ascent near the TC core while maintaining enough distance to prevent shear from overwhelming those effects. This study expands the set of tools for analyzing TC interactions with upper tropospheric flow by improving trough identification and introducing a new perspective through the use of jets. Jets afford greater specificity in describing environmental flow, and allow unique methods of quantifying its impact on TCs. A close relationship is found between jet proximity and vertical shear, as well as jet acceleration and dynamically-forced ascent. Some measures of jet entrance region orientation correlate with the relative magnitude of these influences. Prior research has tended to evaluate such influences individually or relied on case studies to elucidate their collective impact on a single storm. This body of work seeks to illuminate relationships between TCs and upper tropospheric flow that are robust across large samples of TCs and storm environments, utilizing novel approaches such as the jet perspective to extract previously unquantified information. 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 Oct 21 12:19:44 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Mon, 21 Oct 2019 16:19:44 +0000 Subject: [Eoas-seminar] Meteorology PhD Defense for Jason Ducker, November 4, 1:00 PM, Love 353 Message-ID: Meteorology Seminar Jason Ducker PhD Meteorology Candidate Title: Developing new datasets to evaluate tropospheric photochemistry and the effects of ozone uptake in the biosphere Major Professor: Dr. Christopher Holmes Date: November 4, 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 In the presence of water vapor, photolysis of tropospheric ozone (O3) produces the hydroxyl radical (OH), which is a strong oxidant that directly and indirectly controls a host of greenhouse gases and air pollutants. When tropospheric O3 reaches the surface, its oxidative effects perturb plant transpiration and photosynthesis. Although these effects have been included in climate and air quality models, there are limited observational datasets to constrain key aspects of atmospheric photochemistry and O3 deposition on regional to global scales. This dissertation develops and uses two new datasets to better understand the ozone photochemistry and impacts. Photolysis, the breaking of chemical bonds by sunlight, is the engine for reactive atmospheric chemistry. It controls production of atmopsheric oxidants, especially O3 and OH, which then influence the lifetimes of other air pollutants and climate forcing agents. Global chemistry and climate models differ in their estimates of these photolysis rates and there hasnt been datasets capable of discriminating amongst different models. Here, we integrate satellite-retrivals of clouds and aerosols into a photolysis code and produce a 3-D global photolysis dataset called Sat-J. We show that Sat-J is tightly correlated with in-situ measurements of photolysis rates from airborne chemistry campaigns, with errors (4-20%) mainly attributed to differences in cloud sampling and surface albedo characteristics. By comparing regional, not necessarily collocated, averages of aircraft data, SatJ, and a chemistry model (GEOS-Chem); we demonstrate that SatJ provides a representative climatology of photolysis rates across the globe and can serve as a benchmark for photochemistry models. Using surface micrometeorological fluxes and surface O3 monitoring networks, we also develop and evaluate a method to estimate O3 deposition and stomatal O3 uptake across networks of eddy covariance flux tower sites where O3 concentrations and O3 fluxes have not been measured. This method, called SynFlux, reproduces the variability in daily stomatal O3 uptake at sites with O3 flux measurements, with a modest bias (21% or less) attributed to gridded O3 concentrations. Across SynFlux sites, we highlight environmental factors controlling spatial patterns in O3 deposition and showed that previous O3 concentration-based metrics for plant damages did not correlate with SynFlux O3 uptake, which is a better predictor for plant damage than ambient concentration in air. SynFlux has dramatically expanded the available data on surface O3 deposition, which can now be used for performing ecosystem impact studies across a species and climates in the US and Europe. Past controlled experiments involving single plant species have shown that O3 uptake can degrade water-use efficiency (WUE), which is the ratio of carbon uptake in photosynthesis (GPP) to water loss in plant transpiration (T). Using SynFlux sites, we can quantify this effect for whole ecosystems under natural environmental variability, which has not been previously studied. Across 74 SynFlux sites, we find a significant negative relationship (-0.02% per [cid:image001.png at 01D58809.D1F53950] mol m-2 d-1) between daily cumulative O3 uptake (CUO) and WUE anomalies, with the largest impacts occurring at forest sites. Past controlled studies of selected individual species also observed a similar O3 reduction of WUE over the growing season, indicating a consistent response to O3 across multiple species with an ecosystem. When we analyze the relationships between daily CUO and GPP or T anomalies, we also find that CUO degrades GPP and increases T over the growing season. We postulate that O3 degrades WUE through O3 non-stomatal biochemical factors, which result in a reduction of GPP or an increase in T. Our SynFlux results here provide climate models the ability to incorporate O3-dose response relationships between O3 uptake and ecosystem carbon and water vapor fluxes across ecosystems that have not previously been studied. 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: 301 bytes Desc: image001.png URL: From eoas-seminar at lists.fsu.edu Tue Oct 22 08:33:01 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Tue, 22 Oct 2019 12:33:01 +0000 Subject: [Eoas-seminar] Meteorology PhD Defense for Bachir Annane, October 30, 3:00 PM, Love 353 Message-ID: Meteorology Seminar Bachir Annane PhD Meteorology Candidate Title: HWRF ANALYSIS AND FORECAST IMPACT OF CYGNSS OBSERVATIONS ASSIMILATED AS SCALAR WIND SPEEDS AND AS VAM WIND VECTORS Major Professors: Dr. Guosheng Liu and Dr. Ruby Krishnamurti Date: October 30, 2019 Time: 3:00 PM Location: Werner A. Baum Seminar Room (353 Love Building) (Please join us for refreshments served outside room 353 Love @ 2:30 PM) ABSTRACT After decades of focused research into tropical cyclone (TC) dynamics and evolution, operational centers are now able to predict TC track out to a lead time of five days with a high degree of accuracy. However, during this time, forecast skill for TC intensity has not kept the same pace. There are likely many reasons for this slowing improvement in TC intensity forecasts, but the one that is cited often in the community is a lack of frequent and accurate observations of winds in the inner core of TCs. Specifically, current satellite observing systems are unable to penetrate through heavy rainfall, and in situ measurements by aircraft and dropsondes are limited in space and time. The paucity of observations of surface wind speeds in the most dynamically active portion of a TC leads to (1) inaccuracies in the initial conditions used in subsequent model forecasts and (2) insufficient information for evaluating parameterizations of convection and surface fluxes. The NASA Cyclone Global Navigation Satellite System (CYGNSS) mission is designed to address these shortcomings by providing more accurate and timely observations of surface winds in all precipitation conditions. Eight micro-satellites launched in December 2016 (CYGNSS), providing an unprecedented opportunity to obtain ocean surface wind at increased revisit frequency compared to polar-orbiting satellites. Release 2.1 of the CYGNSS data contain improved wind speed quality and can be used to run data impact studies for the cases where the operational center had a weak intensity forecast. This study explores the expected benefits of this retrieved data to numerical simulations of tropical cyclones using two different data assimilation methods within the experimental framework of Observing System Simulation Experiments (OSSE) and Observing System Experiments (OSE). The goals of this study are three-fold: first, investigate the potential for CYGNSS to improve analyses and forecasts of tropical cyclones in an OSSE framework (pre-Launch); second, application of the variational analysis method (VAM) method on the CYGNSS data; third, evaluate the actual influence of assimilating CYGNSS data into NOAA's operational hurricane model (Post-Launch). >From a highly detailed and realistic hurricane nature run (NR), CYGNSS winds were simulated with error characteristics that are expected to occur in reality, and directional information is added using a two dimensional VAM for near-surface vector winds that blends simulated CYGNSS wind speeds with an a priori background vector wind field at 6-h analysis times. The OSSE system makes use of NOAA's Hurricane Weather and Research Forecast (HWRF) model and Gridpoint Statistical Interpolation (GSI) data assimilation system in a configuration that was operational in 2012. CYGNSS winds were assimilated as scalar wind speeds and as wind vectors determined by a variational analysis method. Both forms of wind information had positive impacts on the short-term HWRF forecasts, as shown by key storm and domain metrics. Data assimilation cycle intervals of 1, 3, and 6 hours were tested, and the 3-h impacts were consistently best. The OSE quantifies the impact of assimilating both CYGNSS retrieved wind speed and derived CYGNSS wind vectors in tropical cyclone Michael (2018) on 6-hourly analyses and 5-day forecasts, using the 2019 version of the operational HWRF model. It is found that the assimilation of CYGNSS data results in improved track, intensity, and structure forecasts for both retrieved and derived CYGNSS data, implying the potential benefits of using such data for future research and operational applications. 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 Thu Oct 24 09:30:46 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Thu, 24 Oct 2019 13:30:46 +0000 Subject: [Eoas-seminar] Meteorology MS Defense for Brian Haynes, October 31, 3:30 PM, Love 353 Message-ID: Meteorology Seminar Brian Haynes MS Meteorology Candidate Title: Climate Variability of the Arctic from an Isentropic Potential Vorticity Perspective Major Professor: Dr. Eric Chassignet Date: October 31, 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 The persistence of the positive phase of the Arctic Ocean Oscillation (AOO) during the last two decades is examined by invoking potential vorticity dynamics in a warming Arctic climate to describe tendencies of atmospheric forcing at the Arctic boundary layer. Positive indices of the AOO are indicative of an anti-cyclonic wind stress being imparted at the ice-ocean surface in the Beaufort Sea, a pattern typical during Arctic winters, throughout most of a given year. An IPV framework used to relate increasing Arctic ambient temperatures and sea ice loss with the AOO is achieved by analyzing isentropic output from a blend of the Climate Forecast System Reanalysis (CFSR) and Climate Forecast System version 2 (CFSv2) reanalysis data, as well as surface heat flux output from the same dataset in order to draw conclusions about how diabatic effects may annihilate low-level potential vorticity and reinforce atmospheric stability. These analyses were sectioned into a focus of the inherent differences between positive and negative (cyclonic-regime) phases of the AOO over the time period spanning 1979-2017, with a closer examination pertaining IPV advection and baroclinic development during differing AOO cycles in the Arctic on synoptic timescales. The trends and patterns in Arctic IPV are compared with Arctic sea ice extent and linked to warming by a reduction in the meridional IPV gradient, which in turn weakens the zonal flow and allows for the meridional advection of lower potential vorticity into the region. Baroclinic development of these disturbances vary in location and with season and can amplify ridging downstream, enhancing stationary waves. This implies not only a connection between reduced IPV and the negative phase of the Arctic Oscillation (AO), but that the weakened IPV gradient may allow for transmittance of heat and momentum to the upper levels of the atmosphere, supporting previous studies regarding the impacts that wave-mean flow interaction has on the warming tropopause. These findings demonstrate that the ice melt season, specifically summer and autumn, has an important role in determining the AOO cycle and are supported by IPV theory. 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 Thu Oct 24 09:31:19 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Thu, 24 Oct 2019 13:31:19 +0000 Subject: [Eoas-seminar] Meteorology PhD defense for Levi Cowan, November 1, 2:00 PM, Love 353 Message-ID: Meteorology Seminar Levi Cowan PhD Meteorology Candidate Title: ATLANTIC TROPICAL CYCLONE INTERACTIONS WITH UPPER TROPOSPHERIC TROUGHS AND JETS: IDENTIFICATION, CLIMATOLOGY, AND MODULATION OF TROPICAL CYCLONE INTENSITY Major Professor: Dr. Robert Hart Date: November 1, 2019 Time: 2:00 PM Location: Werner A. Baum Seminar Room (353 Love Building) (Please join us for refreshments served outside room 353 Love @ 1:30 PM) ABSTRACT Interactions of Atlantic tropical cyclones (TCs) with upper tropospheric flow are identified in 37 years of ERA-Interim reanalysis data and analyzed from multiple perspectives. Upper tropospheric troughs are identified in a more comprehensive way than past methodologies, targeting features on the dynamic tropopause to reduce exclusivity of feature selection and sensitivity to the background environment. As a unique way of characterizing and subsetting environmental flow, upper tropospheric jets are identified in 200-hPa wind fields within 3000 km of TCs using a robust, objective algorithm. The climatology of the resulting dataset of jet axes is explored through various means, including an objective clustering technique, which yielded seven statistically distinct groups of jets associated with recognizable flow patterns near TCs. The mean impact of TC outflow on adjacent jets is also quantified, with along-jet acceleration downstream of the TC found to be nearly ubiquitous across the Atlantic basin, though modulated strongly by the geographically varying background state. The influence of nearby upper tropospheric troughs and jets on TC intensity is also assessed through a variety of approaches. In order to minimize systematic sampling biases when quantifying this impact, a spatially varying climatology of TC intensification rate is developed using a second-order, generalized least squares regression model, allowing TC intensity responses to external forcing to be evaluated as departures from their expected value. Both troughs and jets are found to be net negative influences on TC intensity, on average, primarily due to increasing vertical shear with proximity to the vortex. Differences between rapidly intensifying (RI) and rapidly weakening (RW) cases during TC-trough-jet interactions depend not only on shear, but on dynamic forcing imposed by baroclinic processes and eddy momentum fluxes that can counter the influence of shear. Intensifying cases are primarily associated with jets that approach the poleward side of the TC and possess entrance regions that amplify over time, increasing dynamic forcing for ascent near the TC core while maintaining enough distance to prevent shear from overwhelming those effects. This study expands the set of tools for analyzing TC interactions with upper tropospheric flow by improving trough identification and introducing a new perspective through the use of jets. Jets afford greater specificity in describing environmental flow, and allow unique methods of quantifying its impact on TCs. A close relationship is found between jet proximity and vertical shear, as well as jet acceleration and dynamically-forced ascent. Some measures of jet entrance region orientation correlate with the relative magnitude of these influences. Prior research has tended to evaluate such influences individually or relied on case studies to elucidate their collective impact on a single storm. This body of work seeks to illuminate relationships between TCs and upper tropospheric flow that are robust across large samples of TCs and storm environments, utilizing novel approaches such as the jet perspective to extract previously unquantified information. 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 Thu Oct 24 10:36:27 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Thu, 24 Oct 2019 14:36:27 +0000 Subject: [Eoas-seminar] EOAS Colloquium Nov 1: Isla Simpson (NCAR) Message-ID: Dear all, This is a reminder that our next EOAS Colloquium is next Friday November 1, at 3:30 PM in CAR 101. Our speaker will be Dr. Isla Simpson. Dr. Simpson is a scientist in the Climate and Global Dynamics Division at the National Center for Atmospheric Research (NCAR) and she will be speaking about: Multi-decadal variability in the North Atlantic jet stream, its connection to ocean variability and the implications for decadal prediction (abstract below) Please contact Allison Wing (awing at fsu.edu) to schedule a meeting with Dr. Simpson. She studies large-scale atmospheric dynamics and its representation in global climate models. She is particularly interested in understanding the variability and change of the large-scale circulation and its impacts on regional climate and hydroclimate. Her website is: http://www.cgd.ucar.edu/staff/islas/index.html We look forward to seeing you there! Title: Multi-decadal variability in the North Atlantic jet stream, its connection to ocean variability and the implications for decadal prediction. Abstract: The characteristics of the North Atlantic jet stream play a key role in the weather and climate of western Europe. While much of the year to year variability in the jet stream arises from internal atmospheric processes that are inherently unpredictable on timescales beyond a few days to weeks, any low frequency variability that can be considered forced by slowly varying boundary conditions, offers the potential for extended range predictability of climatological conditions in western Europe. Here it will be demonstrated that over the historical record, the North Atlantic jet stream has displayed pronounced multi-decadal variability in the late winter with implications for precipitation in western Europe. This jet stream variability far exceeds that found in state-of-the-art climate models and far exceeds expectations from the sampling of atmospheric noise. It is found that over the observational record there is a strong connection between Sea Surface Temperature (SST) variability and jet stream variability in the North Atlantic and that this connection appears to be absent in models. Nevertheless, given that models can predict SST variability at long lead time, the observed SST-jet stream-precipitation relationship combined with model predicted SST variability offers the potential for extended range predictability of low frequency precipitation variability in western Europe. ?????????????????? Allison Wing, Ph.D. Assistant Professor Earth, Ocean and Atmospheric Science Florida State University awing at fsu.edu -------------- next part -------------- An HTML attachment was scrubbed... URL: From eoas-seminar at lists.fsu.edu Sat Oct 26 09:36:27 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Sat, 26 Oct 2019 13:36:27 +0000 Subject: [Eoas-seminar] Reminder: Geology PhD defense - Farman Ullah - Oct 28, 12pm - 104CAR In-Reply-To: References: Message-ID: Title: Structural Architecture and Jurassic to Eocene Chrono-Stratigraphic Evolution of the North Sulaiman Range, Mughal Kot Gorge, Pakistan. Major Professor: Jim Tull -------------- next part -------------- An HTML attachment was scrubbed... URL: From eoas-seminar at lists.fsu.edu Mon Oct 28 10:09:41 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Mon, 28 Oct 2019 14:09:41 +0000 Subject: [Eoas-seminar] Meteorology PhD Defense for Jason Ducker, November 4, 1:00 PM, Love 353 Message-ID: Meteorology Seminar Jason Ducker PhD Meteorology Candidate Title: Developing new datasets to evaluate tropospheric photochemistry and the effects of ozone uptake in the biosphere Major Professor: Dr. Christopher Holmes Date: November 4, 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 In the presence of water vapor, photolysis of tropospheric ozone (O3) produces the hydroxyl radical (OH), which is a strong oxidant that directly and indirectly controls a host of greenhouse gases and air pollutants. When tropospheric O3 reaches the surface, its oxidative effects perturb plant transpiration and photosynthesis. Although these effects have been included in climate and air quality models, there are limited observational datasets to constrain key aspects of atmospheric photochemistry and O3 deposition on regional to global scales. This dissertation develops and uses two new datasets to better understand the ozone photochemistry and impacts. Photolysis, the breaking of chemical bonds by sunlight, is the engine for reactive atmospheric chemistry. It controls production of atmopsheric oxidants, especially O3 and OH, which then influence the lifetimes of other air pollutants and climate forcing agents. Global chemistry and climate models differ in their estimates of these photolysis rates and there hasnt been datasets capable of discriminating amongst different models. Here, we integrate satellite-retrivals of clouds and aerosols into a photolysis code and produce a 3-D global photolysis dataset called Sat-J. We show that Sat-J is tightly correlated with in-situ measurements of photolysis rates from airborne chemistry campaigns, with errors (4-20%) mainly attributed to differences in cloud sampling and surface albedo characteristics. By comparing regional, not necessarily collocated, averages of aircraft data, SatJ, and a chemistry model (GEOS-Chem); we demonstrate that SatJ provides a representative climatology of photolysis rates across the globe and can serve as a benchmark for photochemistry models. Using surface micrometeorological fluxes and surface O3 monitoring networks, we also develop and evaluate a method to estimate O3 deposition and stomatal O3 uptake across networks of eddy covariance flux tower sites where O3 concentrations and O3 fluxes have not been measured. This method, called SynFlux, reproduces the variability in daily stomatal O3 uptake at sites with O3 flux measurements, with a modest bias (21% or less) attributed to gridded O3 concentrations. Across SynFlux sites, we highlight environmental factors controlling spatial patterns in O3 deposition and showed that previous O3 concentration-based metrics for plant damages did not correlate with SynFlux O3 uptake, which is a better predictor for plant damage than ambient concentration in air. SynFlux has dramatically expanded the available data on surface O3 deposition, which can now be used for performing ecosystem impact studies across a species and climates in the US and Europe. Past controlled experiments involving single plant species have shown that O3 uptake can degrade water-use efficiency (WUE), which is the ratio of carbon uptake in photosynthesis (GPP) to water loss in plant transpiration (T). Using SynFlux sites, we can quantify this effect for whole ecosystems under natural environmental variability, which has not been previously studied. Across 74 SynFlux sites, we find a significant negative relationship (-0.02% per [cid:image001.png at 01D58D77.CFC4BF20] mol m-2 d-1) between daily cumulative O3 uptake (CUO) and WUE anomalies, with the largest impacts occurring at forest sites. Past controlled studies of selected individual species also observed a similar O3 reduction of WUE over the growing season, indicating a consistent response to O3 across multiple species with an ecosystem. When we analyze the relationships between daily CUO and GPP or T anomalies, we also find that CUO degrades GPP and increases T over the growing season. We postulate that O3 degrades WUE through O3 non-stomatal biochemical factors, which result in a reduction of GPP or an increase in T. Our SynFlux results here provide climate models the ability to incorporate O3-dose response relationships between O3 uptake and ecosystem carbon and water vapor fluxes across ecosystems that have not previously been studied. 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: 301 bytes Desc: image001.png URL: From eoas-seminar at lists.fsu.edu Mon Oct 28 10:07:03 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Mon, 28 Oct 2019 14:07:03 +0000 Subject: [Eoas-seminar] Biogeochemistry Seminar Friday Nov. 1, 2019 12:15 327 OSB Message-ID: Biogeochemistry Seminar Friday Nov. 1, 2019 327 OSB 12:15-13:15 Luis Rodriguez Abstract: The Holocene is considered a period of relative climatic stability, but significant proxy data?model discrepancies exist that preclude consensus regarding the postglacial global temperature trajectory. In particular, a mid?Holocene Climatic Optimum, ~9,000 to ~5,000 years BP, is evident in Northern Hemisphere marine sediment records, but its absence from model simulations raises key questions about the ability of the models to accurately simulate climate and seasonal biases that may be present in the proxy records. Here we present new mid?Holocene sea surface temperature (SST) data from the western tropical Atlantic, where twentieth?century temperature variability and amplitude of warming track the twentieth?century global ocean. Using a new coral thermometer Sr?U, we first developed a temporal Sr?U SST calibration from three modern Atlantic corals and validated the calibration against Sr?U time series from a fourth modern coral. Two fossil corals from the Enriquillo Valley, Dominican Republic, were screened for diagenesis, U?series dated to 5,199 ? 26 and 6,427 ? 81 years BP, respectively, and analyzed for Sr/Ca and U/Ca, generating two annually resolved Sr?U SST records, 27 and 17 years long, respectively. Average SSTs from both corals were significantly cooler than in early instrumental (1870?1920) and late instrumental (1965?2016) periods at this site, by ~0.5 and ~0.75 ?C, respectively, a result inconsistent with the extended mid?Holocene warm period inferred from sediment records. A more complete sampling of Atlantic Holocene corals can resolve this issue with confidence and address questions related to multidecadal and longer?term variability in Holocene Atlantic climate. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ William M. Landing, Ph.D. Department of Earth, Ocean, and Atmospheric Science Florida State University 117 N. Woodward Ave., Tallahassee, FL 32306-4320 850-644-6037; 850-644-2581 FAX wlanding at fsu.edu; http://www.eoas.fsu.edu +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ From eoas-seminar at lists.fsu.edu Tue Oct 29 10:18:16 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Tue, 29 Oct 2019 14:18:16 +0000 Subject: [Eoas-seminar] Meteorology PhD Defense for Bachir Annane, October 30, 3:00 PM, Love 353 Message-ID: Meteorology Seminar Bachir Annane PhD Meteorology Candidate Title: HWRF ANALYSIS AND FORECAST IMPACT OF CYGNSS OBSERVATIONS ASSIMILATED AS SCALAR WIND SPEEDS AND AS VAM WIND VECTORS Major Professors: Dr. Guosheng Liu and Dr. Ruby Krishnamurti Date: October 30, 2019 Time: 3:00 PM Location: Werner A. Baum Seminar Room (353 Love Building) (Please join us for refreshments served outside room 353 Love @ 2:30 PM) ABSTRACT After decades of focused research into tropical cyclone (TC) dynamics and evolution, operational centers are now able to predict TC track out to a lead time of five days with a high degree of accuracy. However, during this time, forecast skill for TC intensity has not kept the same pace. There are likely many reasons for this slowing improvement in TC intensity forecasts, but the one that is cited often in the community is a lack of frequent and accurate observations of winds in the inner core of TCs. Specifically, current satellite observing systems are unable to penetrate through heavy rainfall, and in situ measurements by aircraft and dropsondes are limited in space and time. The paucity of observations of surface wind speeds in the most dynamically active portion of a TC leads to (1) inaccuracies in the initial conditions used in subsequent model forecasts and (2) insufficient information for evaluating parameterizations of convection and surface fluxes. The NASA Cyclone Global Navigation Satellite System (CYGNSS) mission is designed to address these shortcomings by providing more accurate and timely observations of surface winds in all precipitation conditions. Eight micro-satellites launched in December 2016 (CYGNSS), providing an unprecedented opportunity to obtain ocean surface wind at increased revisit frequency compared to polar-orbiting satellites. Release 2.1 of the CYGNSS data contain improved wind speed quality and can be used to run data impact studies for the cases where the operational center had a weak intensity forecast. This study explores the expected benefits of this retrieved data to numerical simulations of tropical cyclones using two different data assimilation methods within the experimental framework of Observing System Simulation Experiments (OSSE) and Observing System Experiments (OSE). The goals of this study are three-fold: first, investigate the potential for CYGNSS to improve analyses and forecasts of tropical cyclones in an OSSE framework (pre-Launch); second, application of the variational analysis method (VAM) method on the CYGNSS data; third, evaluate the actual influence of assimilating CYGNSS data into NOAA's operational hurricane model (Post-Launch). >From a highly detailed and realistic hurricane nature run (NR), CYGNSS winds were simulated with error characteristics that are expected to occur in reality, and directional information is added using a two dimensional VAM for near-surface vector winds that blends simulated CYGNSS wind speeds with an a priori background vector wind field at 6-h analysis times. The OSSE system makes use of NOAA's Hurricane Weather and Research Forecast (HWRF) model and Gridpoint Statistical Interpolation (GSI) data assimilation system in a configuration that was operational in 2012. CYGNSS winds were assimilated as scalar wind speeds and as wind vectors determined by a variational analysis method. Both forms of wind information had positive impacts on the short-term HWRF forecasts, as shown by key storm and domain metrics. Data assimilation cycle intervals of 1, 3, and 6 hours were tested, and the 3-h impacts were consistently best. The OSE quantifies the impact of assimilating both CYGNSS retrieved wind speed and derived CYGNSS wind vectors in tropical cyclone Michael (2018) on 6-hourly analyses and 5-day forecasts, using the 2019 version of the operational HWRF model. It is found that the assimilation of CYGNSS data results in improved track, intensity, and structure forecasts for both retrieved and derived CYGNSS data, implying the potential benefits of using such data for future research and operational applications. 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 Oct 29 10:00:11 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Tue, 29 Oct 2019 14:00:11 +0000 Subject: [Eoas-seminar] EOAS Colloquium Nov 1: Isla Simpson (NCAR) In-Reply-To: References: Message-ID: Dear all, Just a reminder of the EOAS Colloquium Friday at 3:30 given by Dr. Isla Simpson on ?Multi-decadal variability in the North Atlantic jet stream, its connection to ocean variability and the implications for decadal prediction?. There are a couple spots left in her schedule; if you would like to meet with Dr. Simpson please contact Allison Wing (awing at fsu.edu) See you there! ?????????????????? Allison Wing, Ph.D. Assistant Professor Earth, Ocean and Atmospheric Science Florida State University awing at fsu.edu On Oct 24, 2019, at 10:36 AM, eoas-seminar--- via Eoas-seminar > wrote: Dear all, This is a reminder that our next EOAS Colloquium is next Friday November 1, at 3:30 PM in CAR 101. Our speaker will be Dr. Isla Simpson. Dr. Simpson is a scientist in the Climate and Global Dynamics Division at the National Center for Atmospheric Research (NCAR) and she will be speaking about: Multi-decadal variability in the North Atlantic jet stream, its connection to ocean variability and the implications for decadal prediction (abstract below) Please contact Allison Wing (awing at fsu.edu) to schedule a meeting with Dr. Simpson. She studies large-scale atmospheric dynamics and its representation in global climate models. She is particularly interested in understanding the variability and change of the large-scale circulation and its impacts on regional climate and hydroclimate. Her website is: http://www.cgd.ucar.edu/staff/islas/index.html We look forward to seeing you there! Title: Multi-decadal variability in the North Atlantic jet stream, its connection to ocean variability and the implications for decadal prediction. Abstract: The characteristics of the North Atlantic jet stream play a key role in the weather and climate of western Europe. While much of the year to year variability in the jet stream arises from internal atmospheric processes that are inherently unpredictable on timescales beyond a few days to weeks, any low frequency variability that can be considered forced by slowly varying boundary conditions, offers the potential for extended range predictability of climatological conditions in western Europe. Here it will be demonstrated that over the historical record, the North Atlantic jet stream has displayed pronounced multi-decadal variability in the late winter with implications for precipitation in western Europe. This jet stream variability far exceeds that found in state-of-the-art climate models and far exceeds expectations from the sampling of atmospheric noise. It is found that over the observational record there is a strong connection between Sea Surface Temperature (SST) variability and jet stream variability in the North Atlantic and that this connection appears to be absent in models. Nevertheless, given that models can predict SST variability at long lead time, the observed SST-jet stream-precipitation relationship combined with model predicted SST variability offers the potential for extended range predictability of low frequency precipitation variability in western Europe. ?????????????????? Allison Wing, Ph.D. Assistant Professor Earth, Ocean and Atmospheric Science Florida State University awing at fsu.edu _______________________________________________ Eoas-seminar mailing list Eoas-seminar at lists.fsu.edu https://lists.fsu.edu/mailman/listinfo/eoas-seminar -------------- next part -------------- An HTML attachment was scrubbed... URL: From eoas-seminar at lists.fsu.edu Wed Oct 30 08:59:23 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Wed, 30 Oct 2019 12:59:23 +0000 Subject: [Eoas-seminar] Meteorology PhD Defense for Bachir Annane, October 30, 3:00 PM, Love 353 Message-ID: Meteorology Seminar Bachir Annane PhD Meteorology Candidate Title: HWRF ANALYSIS AND FORECAST IMPACT OF CYGNSS OBSERVATIONS ASSIMILATED AS SCALAR WIND SPEEDS AND AS VAM WIND VECTORS Major Professors: Dr. Guosheng Liu and Dr. Ruby Krishnamurti Date: October 30, 2019 Time: 3:00 PM Location: Werner A. Baum Seminar Room (353 Love Building) (Please join us for refreshments served outside room 353 Love @ 2:30 PM) ABSTRACT After decades of focused research into tropical cyclone (TC) dynamics and evolution, operational centers are now able to predict TC track out to a lead time of five days with a high degree of accuracy. However, during this time, forecast skill for TC intensity has not kept the same pace. There are likely many reasons for this slowing improvement in TC intensity forecasts, but the one that is cited often in the community is a lack of frequent and accurate observations of winds in the inner core of TCs. Specifically, current satellite observing systems are unable to penetrate through heavy rainfall, and in situ measurements by aircraft and dropsondes are limited in space and time. The paucity of observations of surface wind speeds in the most dynamically active portion of a TC leads to (1) inaccuracies in the initial conditions used in subsequent model forecasts and (2) insufficient information for evaluating parameterizations of convection and surface fluxes. The NASA Cyclone Global Navigation Satellite System (CYGNSS) mission is designed to address these shortcomings by providing more accurate and timely observations of surface winds in all precipitation conditions. Eight micro-satellites launched in December 2016 (CYGNSS), providing an unprecedented opportunity to obtain ocean surface wind at increased revisit frequency compared to polar-orbiting satellites. Release 2.1 of the CYGNSS data contain improved wind speed quality and can be used to run data impact studies for the cases where the operational center had a weak intensity forecast. This study explores the expected benefits of this retrieved data to numerical simulations of tropical cyclones using two different data assimilation methods within the experimental framework of Observing System Simulation Experiments (OSSE) and Observing System Experiments (OSE). The goals of this study are three-fold: first, investigate the potential for CYGNSS to improve analyses and forecasts of tropical cyclones in an OSSE framework (pre-Launch); second, application of the variational analysis method (VAM) method on the CYGNSS data; third, evaluate the actual influence of assimilating CYGNSS data into NOAA's operational hurricane model (Post-Launch). >From a highly detailed and realistic hurricane nature run (NR), CYGNSS winds were simulated with error characteristics that are expected to occur in reality, and directional information is added using a two dimensional VAM for near-surface vector winds that blends simulated CYGNSS wind speeds with an a priori background vector wind field at 6-h analysis times. The OSSE system makes use of NOAA's Hurricane Weather and Research Forecast (HWRF) model and Gridpoint Statistical Interpolation (GSI) data assimilation system in a configuration that was operational in 2012. CYGNSS winds were assimilated as scalar wind speeds and as wind vectors determined by a variational analysis method. Both forms of wind information had positive impacts on the short-term HWRF forecasts, as shown by key storm and domain metrics. Data assimilation cycle intervals of 1, 3, and 6 hours were tested, and the 3-h impacts were consistently best. The OSE quantifies the impact of assimilating both CYGNSS retrieved wind speed and derived CYGNSS wind vectors in tropical cyclone Michael (2018) on 6-hourly analyses and 5-day forecasts, using the 2019 version of the operational HWRF model. It is found that the assimilation of CYGNSS data results in improved track, intensity, and structure forecasts for both retrieved and derived CYGNSS data, implying the potential benefits of using such data for future research and operational applications. 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 Wed Oct 30 08:59:51 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Wed, 30 Oct 2019 12:59:51 +0000 Subject: [Eoas-seminar] Meteorology MS Defense for Brian Haynes, October 31, 3:30 PM, Love 353 Message-ID: Meteorology Seminar Brian Haynes MS Meteorology Candidate Title: Climate Variability of the Arctic from an Isentropic Potential Vorticity Perspective Major Professor: Dr. Eric Chassignet Date: October 31, 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 The persistence of the positive phase of the Arctic Ocean Oscillation (AOO) during the last two decades is examined by invoking potential vorticity dynamics in a warming Arctic climate to describe tendencies of atmospheric forcing at the Arctic boundary layer. Positive indices of the AOO are indicative of an anti-cyclonic wind stress being imparted at the ice-ocean surface in the Beaufort Sea, a pattern typical during Arctic winters, throughout most of a given year. An IPV framework used to relate increasing Arctic ambient temperatures and sea ice loss with the AOO is achieved by analyzing isentropic output from a blend of the Climate Forecast System Reanalysis (CFSR) and Climate Forecast System version 2 (CFSv2) reanalysis data, as well as surface heat flux output from the same dataset in order to draw conclusions about how diabatic effects may annihilate low-level potential vorticity and reinforce atmospheric stability. These analyses were sectioned into a focus of the inherent differences between positive and negative (cyclonic-regime) phases of the AOO over the time period spanning 1979-2017, with a closer examination pertaining IPV advection and baroclinic development during differing AOO cycles in the Arctic on synoptic timescales. The trends and patterns in Arctic IPV are compared with Arctic sea ice extent and linked to warming by a reduction in the meridional IPV gradient, which in turn weakens the zonal flow and allows for the meridional advection of lower potential vorticity into the region. Baroclinic development of these disturbances vary in location and with season and can amplify ridging downstream, enhancing stationary waves. This implies not only a connection between reduced IPV and the negative phase of the Arctic Oscillation (AO), but that the weakened IPV gradient may allow for transmittance of heat and momentum to the upper levels of the atmosphere, supporting previous studies regarding the impacts that wave-mean flow interaction has on the warming tropopause. These findings demonstrate that the ice melt season, specifically summer and autumn, has an important role in determining the AOO cycle and are supported by IPV theory. 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 Wed Oct 30 10:29:00 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Wed, 30 Oct 2019 14:29:00 +0000 Subject: [Eoas-seminar] =?utf-8?q?COAPS_SEMINAR=3A_=E2=80=9CSeeding_snow?= =?utf-8?q?=3A_Mississippi_River_plume_interaction_with_surface_oil_in_the?= =?utf-8?q?_northern_Gulf_of_Mexico=E2=80=9D_by_Catherine_Edwards_-_Novemb?= =?utf-8?q?er_13_at_3pm?= Message-ID: Dr. Catherine Edwards Skidaway Institute of Oceanography University of Georgia ?Seeding snow: Mississippi River plume interaction with surface oil in the northern Gulf of Mexico? Wednesday, November 13 - 3:00 pm COAPS seminar room 255, Research Building A Directions: https://www.coaps.fsu.edu/about-us/visitor-information Abstract: Glider data collected in the upper 200 m during a month-long mission in the northern Gulf of Mexico indicate formation of marine oil snow (MOS) after the arrival of fresh river plume water over the continental slope site approximately 200 nm offshore. The putative MOS signal, captured near Green Canyon lease block 600 (GC600), appears in the fluorescence data as large particles with high concentration of both colored dissolved organic matter (CDOM) and chlorophyll-a fluorescence, extending well below the photic zone to at least 190 m depth. Closer examination of the time series suggests a strong diel cycle in concentration of MOS aggregates, with distribution through the upper 190 m during the day and zero signal between local sundown and sunrise. ADCP backscatter from a nearby ship shows diel vertical migration of scatterers of approximately 800 ?m in radius. The size and behavior of the scatterers is consistent with mesozooplankton. Direct measurement of MOS concentration or zooplankton population was not possible with this data set; however, the data are consistent with MOS formation under a fresh water plume, with diel clearing of the aggregates each night by zooplankton grazing. The implications for this previously unknown process of MOS formation and zooplankton-mediated export are explored with respect to system dynamics of natural seeps and the anomalous nature of the 2015 fresh water event. -- Eric Chassignet Professor and Director Center for Ocean-Atmospheric Prediction Studies (COAPS) Florida State University 2000 Levy Avenue, Building A, Suite 292 P.O. Box 3062741 Tallahassee, FL 32306-2741 Office : (1) 850-645-7288 COAPS : (1) 850-644-3846 Cell : (1) 850-524-0033 (urgent matters only) FAX : (1) 850-644-4841 E-mail : echassignet at fsu.edu http://www.coaps.fsu.edu -------------- next part -------------- An HTML attachment was scrubbed... URL: From eoas-seminar at lists.fsu.edu Thu Oct 31 16:13:55 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Thu, 31 Oct 2019 20:13:55 +0000 Subject: [Eoas-seminar] Meteorology PhD defense for Levi Cowan, November 1, 2:00 PM, Love 353 Message-ID: Meteorology Seminar Levi Cowan PhD Meteorology Candidate Title: ATLANTIC TROPICAL CYCLONE INTERACTIONS WITH UPPER TROPOSPHERIC TROUGHS AND JETS: IDENTIFICATION, CLIMATOLOGY, AND MODULATION OF TROPICAL CYCLONE INTENSITY Major Professor: Dr. Robert Hart Date: November 1, 2019 Time: 2:00 PM Location: Werner A. Baum Seminar Room (353 Love Building) (Please join us for refreshments served outside room 353 Love @ 1:30 PM) ABSTRACT Interactions of Atlantic tropical cyclones (TCs) with upper tropospheric flow are identified in 37 years of ERA-Interim reanalysis data and analyzed from multiple perspectives. Upper tropospheric troughs are identified in a more comprehensive way than past methodologies, targeting features on the dynamic tropopause to reduce exclusivity of feature selection and sensitivity to the background environment. As a unique way of characterizing and subsetting environmental flow, upper tropospheric jets are identified in 200-hPa wind fields within 3000 km of TCs using a robust, objective algorithm. The climatology of the resulting dataset of jet axes is explored through various means, including an objective clustering technique, which yielded seven statistically distinct groups of jets associated with recognizable flow patterns near TCs. The mean impact of TC outflow on adjacent jets is also quantified, with along-jet acceleration downstream of the TC found to be nearly ubiquitous across the Atlantic basin, though modulated strongly by the geographically varying background state. The influence of nearby upper tropospheric troughs and jets on TC intensity is also assessed through a variety of approaches. In order to minimize systematic sampling biases when quantifying this impact, a spatially varying climatology of TC intensification rate is developed using a second-order, generalized least squares regression model, allowing TC intensity responses to external forcing to be evaluated as departures from their expected value. Both troughs and jets are found to be net negative influences on TC intensity, on average, primarily due to increasing vertical shear with proximity to the vortex. Differences between rapidly intensifying (RI) and rapidly weakening (RW) cases during TC-trough-jet interactions depend not only on shear, but on dynamic forcing imposed by baroclinic processes and eddy momentum fluxes that can counter the influence of shear. Intensifying cases are primarily associated with jets that approach the poleward side of the TC and possess entrance regions that amplify over time, increasing dynamic forcing for ascent near the TC core while maintaining enough distance to prevent shear from overwhelming those effects. This study expands the set of tools for analyzing TC interactions with upper tropospheric flow by improving trough identification and introducing a new perspective through the use of jets. Jets afford greater specificity in describing environmental flow, and allow unique methods of quantifying its impact on TCs. A close relationship is found between jet proximity and vertical shear, as well as jet acceleration and dynamically-forced ascent. Some measures of jet entrance region orientation correlate with the relative magnitude of these influences. Prior research has tended to evaluate such influences individually or relied on case studies to elucidate their collective impact on a single storm. This body of work seeks to illuminate relationships between TCs and upper tropospheric flow that are robust across large samples of TCs and storm environments, utilizing novel approaches such as the jet perspective to extract previously unquantified information. 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 Thu Oct 31 17:02:30 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Thu, 31 Oct 2019 21:02:30 +0000 Subject: [Eoas-seminar] Dr. Julia Sigwart Seminar, Nov. 4th, 4 pm, King 2057 Message-ID: Please join us for the seminar of Dr. Julia Sigwart titled: What species mean: A user's guide to the units of biodiversity Monday, Nov. 4th, 4 pm, King 2057 More information on Dr. Sigwart and her presentation is available on the attached announcement. 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: Sigwart seminar .pdf Type: application/pdf Size: 1660201 bytes Desc: Sigwart seminar .pdf URL: