From eoas-seminar at lists.fsu.edu Mon Jul 1 12:30:18 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Mon, 1 Jul 2019 16:30:18 +0000 Subject: [Eoas-seminar] Meteorology MS Defense for John Uehling, Tuesday, July 2, 2019, 1:00 PM, LOV 353 Message-ID: Meteorology Seminar John Uehling MS Meteorology Candidate Title: Major Professor: Dr. Vasu Misra Date: July 2nd, 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 A comprehensive rainfall-based index of the Australian monsoon is created. This index is based on methodology previously used on the Indian subcontinent for determining the seasonality of the Indian monsoon. In order to create the Australian monsoon index, only rainfall data is used, which even over the sparsely populated areas of northern Australia is available dating back over 100 years (to 1901). The methodology for calculating the Australian monsoon index has been shown to be robust and not susceptible to false onsets. The Australian monsoon index objectively captures the onset date, the demise date, and the total seasonal rainfall for each monsoon season. This new index was then compared to various atmospheric dynamic and thermodynamic variables to see if the index was reflective of the broader seasonal atmospheric changes associated with the monsoon. The Australian monsoon index introduced in this study is found to be consistent with the meridional advancement of the precipitable water south of the equator and over the Australian land mass as the monsoon season begins. Atmospheric dynamics related to the low-level wind data shows a pronounced wind shift across the region corresponding to the onset and the demise of the monsoon based on the rainfall index. The examination of linear trends show that the length of the season has gotten longer and wetter, with earlier onsets and later demises since the beginning of the 20th century. One final aspect of the monsoon that is investigated is the interannual variability of the monsoon and how the El Ni?o-Southern Oscillation (ENSO) impacts the onset, demise, length of season, and total rainfall of the Australian monsoon. It is observed that warm or cold ENSO events are associated with shorter or longer Australian monsoon season, respectively. Similarly, these warm or cold ENSO events are associated with drier or wetter seasonal rainfall anomalies of the Australian monsoon, respectively. 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 Jul 1 13:05:02 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Mon, 1 Jul 2019 17:05:02 +0000 Subject: [Eoas-seminar] TIME CHANGE: Meteorology MS Defense for John Uehling, Tuesday, July 2, 2019, 3:00 PM, LOV 353 Message-ID: Meteorology Seminar John Uehling MS Meteorology Candidate Title: Describing the onset and demise of the Australian Monsoon Major Professor: Dr. Vasu Misra Date: July 2nd, 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 A comprehensive rainfall-based index of the Australian monsoon is created. This index is based on methodology previously used on the Indian subcontinent for determining the seasonality of the Indian monsoon. In order to create the Australian monsoon index, only rainfall data is used, which even over the sparsely populated areas of northern Australia is available dating back over 100 years (to 1901). The methodology for calculating the Australian monsoon index has been shown to be robust and not susceptible to false onsets. The Australian monsoon index objectively captures the onset date, the demise date, and the total seasonal rainfall for each monsoon season. This new index was then compared to various atmospheric dynamic and thermodynamic variables to see if the index was reflective of the broader seasonal atmospheric changes associated with the monsoon. The Australian monsoon index introduced in this study is found to be consistent with the meridional advancement of the precipitable water south of the equator and over the Australian land mass as the monsoon season begins. Atmospheric dynamics related to the low-level wind data shows a pronounced wind shift across the region corresponding to the onset and the demise of the monsoon based on the rainfall index. The examination of linear trends show that the length of the season has gotten longer and wetter, with earlier onsets and later demises since the beginning of the 20th century. One final aspect of the monsoon that is investigated is the interannual variability of the monsoon and how the El Ni?o-Southern Oscillation (ENSO) impacts the onset, demise, length of season, and total rainfall of the Australian monsoon. It is observed that warm or cold ENSO events are associated with shorter or longer Australian monsoon season, respectively. Similarly, these warm or cold ENSO events are associated with drier or wetter seasonal rainfall anomalies of the Australian monsoon, respectively. 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 Jul 8 09:05:33 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Mon, 8 Jul 2019 13:05:33 +0000 Subject: [Eoas-seminar] Meteorology PhD Defense for Tristan Hall, Tuesday, July 9, 2019, 1:00 PM, LOV353 Message-ID: Meteorology Seminar Tristan Hall PhD Meteorology Candidate Title: A climatology of U.S. tropical cyclone rainfall, its use in a statistical forecasting technique and an analysis of Global Forecast System tropical cyclone rainfall forecast environments Major Professor: Dr. Henry Fuelberg Date: July 9th, 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 While advances in tropical cyclone (TC) track forecasting have been substantial over the past few decades, and modest advances in intensity forecasting have occurred more recently, the quality of TC rainfall forecasts has not undergone the same rigorous veri?cation. This is despite the 27% of total TC-related deaths being due to rainfall-induced ?ooding and that rainfall-related deaths occur more frequently than those due to any another weather-related hazard. A continual e?ort is needed to understand and better-forecast TC rainfall. This dissertation research seeks to contribute to this endeavor. A climatological dataset is created using 6-h Stage IV rainfall accumulations combined with Best Track 6-h locations for all TCs within 300 km of the U.S. Gulf and Atlantic coastlines during years 2004 ? 2013. Stage IV data are used due to their higher spatiotemporal resolution, their extension to high latitudes, and because they have been found to be the superior option when compared to other TC rainfall data sources. The 6-h Stage IV rainfall accumulations are composited by shear magnitude and storm intensity in earth-, motion-, and shear-relative reference frames. Additionally, a full composite comprised of all storms is created. This compositing is done for TCs impacting the U.S. Gulf and Atlantic coastlines. Seven geographical regions are created within this domain to further composite the rainfall. The geographical regions are determined based on 2004 ? 2013 Best Track (HURDAT2) landfall locations. Results show that some Stage IV rain rate characteristics, especially those in speci?c regions, are di?erent when compared to prior ?ndings based on satellite-derived rain rates. Results from the Stage IV-derived climatological datasets then are used together with track forecasts from the Global Forecast System (GFS) during years 2014 ? 2016 to create 72-h TC rainfall forecasts. Separate forecasts are created for each 6-h TC position forecast based on shear magnitude, storm intensity, and the all-storms composites in earth-, motion-, and shear-relative reference frames. This yielded 1,290 veri?able forecasts during the 3-yr period. These statistical rainfall forecasts along with forecasts from the GFS are veri?ed using the Fractions Skill Score (FSS) metric. Results show that the statistical method based on shear magnitude in a shear relative reference frame that used regional rainfall composites is the best performing of the methods. These preliminary results show that this method is a viable candidate to supplement the GFS in forecasting TC rainfall. GFS analysis and forecast environmental parameters are composited based on the skill (FSS) of each forecast. Three categories are created: Top (FSS > 0.6), Bottom (FSS < 0.3), and Middle (0.3 < FSS < 0.6). This methodology is based on the desire to provide ?guidance on guidance,? i.e., suggesting to a forecaster whether the TC?s environment is conducive to a skillful or not-skillful GFS rainfall forecast. Results show that some aspects of the mean sea level pressure, 1000 ? 500 hPa thickness anomalies, eddy ?ux convergence, and upper-level winds and divergence di?er between skillful and non-skillful TC rainfall forecasts. 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 Jul 9 12:03:42 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Tue, 9 Jul 2019 16:03:42 +0000 Subject: [Eoas-seminar] REMINDER -- GFDI COLLOQUIUM ON WEDNESDAY, JULY 10th AT 11:00AM in MELVIN STERN SEMINAR ROOM, #18 KEEN BUILDING In-Reply-To: References: Message-ID: Title ?Direct Numerical Simulation of a Spatially-Developing Turbulent Mixing Layer" Speaker Dr. Svetlana V. Poroseva Department of Mechanical Engineering University of New Mexico Time and Place 11:00AM, Wednesday, July 10, 2019 Melvin Stern Seminar/Reading Room 18 Keen Building Refreshments will be served at 10:30AM ABSTRACT: Understanding spatial development of a turbulent mixing layer is essential for many applications. However, multiple factors affect the physics of this flow, making it difficult to replicate experiments, either physical or numerical. Direct numerical simulation (DNS) allows for more control over the simulation inputs and is free from modeling assumptions. This makes the method attractive for studying the flow physics. However, the cost of DNS complicates such an analysis and also that of the generated data accuracy. In our study, a thorough sensitivity analysis of simulations was conducted before collecting the flow statistics. To reduce uncertainty in the simulation results, no artificial perturbations were introduced to trigger the flow transition to turbulence. Flow conditions in the simulations were based on those from the experiments by Bell & Mehta (1990), where a mixing layer was obtained from two untripped boundary layers formed on both sides of a splitter plate. The simulation domain was long enough to reach a self-similar region. Statistics were collected up to the fifth-order velocity moments. The simulations were conducted using the spectral-element code Nek5000. This study is a collaboration between the University of New Mexico, Arizona State University, and NASA Ames Research Center. -------------- next part -------------- An HTML attachment was scrubbed... URL: From eoas-seminar at lists.fsu.edu Sat Jul 13 14:31:12 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Sat, 13 Jul 2019 18:31:12 +0000 Subject: [Eoas-seminar] Oceanography Masters Defense - Adam Alfasso - July 16, 2:00pm - 327OSB Message-ID: Earth Ocean and Atmospheric Sciences Environmental Sciences Degree I am happy to announce that Adam Alfasso will be defending his M.S. thesis: HABITAT SUITABILITY MODELLING OF SHALLOW WATER STRUCTURE-FORMING COMMUNITIES IN THE BIG BEND REGION OF FLORIDA?S NORTHEASTERN GULF OF MEXICO Date: Tuesday July 16th Location: Oceanography and Statistics building (OSB) Room 327 Time: 14:00 in OSB 327. Hope to see you there! Major professor: Sandra Brooke -------------- next part -------------- An HTML attachment was scrubbed... URL: From eoas-seminar at lists.fsu.edu Wed Jul 24 13:24:53 2019 From: eoas-seminar at lists.fsu.edu (eoas-seminar at lists.fsu.edu) Date: Wed, 24 Jul 2019 17:24:53 +0000 Subject: [Eoas-seminar] Meteorology PhD Defense for Kyle Ahern, August 8th, 3:30 PM, Love 353 Message-ID: Meteorology Seminar Kyle Ahern PhD Meteorology Candidate Title: Hurricane Boundary Layer Structure During Intensity Change: An Observational and Numerical Analysis Major Professor: Dr. Mark Bourassa and Dr. Robert Hart Date: August 8th, 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 A combination of observational and numerical analyses is used to investigate hurricane boundary layer (BL) structure in the context of intensity change. These analyses refer to hurricanes in three modes of intensity change: intensifying (IN), steady-state (SS), and weakening (WE). Observations from GPS dropwindsondes launched in Atlantic tropical cyclones between 1998 and 2015 are collected for compositing based on intensity change. After quality control and sorting, 3,091 dropwindsondes were composited. In non-intensifying hurricanes, lower-tropospheric tangential winds were stronger than IN storms outside the radius of maximum winds (RMW), which suggests greater inertial stability [cid:image001.png at 01D54223.2CA2E820] outside the RMW in non-intensifying hurricanes. The BL radial inflow is of similar thickness across the three composites, and all composite groups have an inflow maximum situated at the RMW. Non-intensifying hurricanes are associated with stronger near-surface inflow outside the eyewall, implying more frictionally forced ascent out of the BL at radii outside the RMW. At greater radii, inflow layer [cid:image002.png at 01D54223.2CA2E820] is relatively low in the WE composite, suggesting locally enhanced subsidence or downdrafts. High-resolution numerical case studies of Hurricane Irma in 2017 and Hurricane Earl in 2010 are used to check results found in the composite analysis and highlight BL azimuthal structure. The Weather Research and Forecasting Model for Advanced Research (WRF-ARW) is employed for these full-physics simulations. Irma's strong tangential winds were relatively confined to the RMW, leading to weak [cid:image001.png at 01D54223.2CA2E820] outside the eyewall. Aside from land interactions, Irma tended to steadily intensify, with an inflow maximum at the RMW and BL ascent isolated inward of the RMW. A brief WE period in Irma was associated with shear- and motion-induced asymmetry, whereby drier air was able to descend into the BL inflow near the RMW. Hurricane Earl had a broader tangential wind field, with high [cid:image001.png at 01D54223.2CA2E820] outside the eyewall. Earl's strong BL inflow spread over a large radial band, which was associated with widespread BL convergence and shallow ascent outside the RMW. During a prolonged and progressive decay in Earl's intensity, two regions of BL convergence became apparent: one inward of the RMW, and the other well outside the RMW. Descent of low-enthalpy air into the BL near the RMW occurred during Earl's WE phases. Despite shear and storm motion of comparable magnitude to Irma, asymmetries were more pronounced in Earl's BL. Earl's intensity decline was also associated with strong low-level outflow in the upshear-right quadrant, which may have led to structural evolution that promoted an outer region of BL convergence, as well as an inner-eyewall collapse and coincident secondary eyewall formation. 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: 329 bytes Desc: image001.png URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: image002.png Type: image/png Size: 359 bytes Desc: image002.png URL: