Oceanography and Atmospheric Sciences and Meteorology Commons^™

A New Analysis Of The Gálvez-Davison Index For Convective Forecasts In Northern Africa, Gabriel D. Donndelinger

Theses and Dissertations

Severe wind gusts and thunderstorms have been difficult to forecast in Africa. Traditional convective forecast tools (e.g. Total Totals Index, Lifted Index, K Index (KI) and Convective Available Potential Energy) do not accurately portray potential for thunderstorms in Africa. This research effort used the Gálvez-Davison Index (GDI), a convective index created for the tropics, and assess its applicability to northern Africa. GDI was produced for the Caribbean and Central America, and utilized temperature, moisture, mid-level stability, dry air entrainment and an elevation factor to calculate convective potential. In this research, GDI and KI were calculated using Global Forecast System (GFS) …

The Geographic Distribution Of Downburst Frequency Across Spaceport Florida, Tania M. Garza

Theses and Dissertations

Strong winds from downbursts pose a significant hazard to personnel and launch operations at Cape Canaveral Air Force Station (CCAFS) and NASA Kennedy Space Center (KSC). The CCAFS/KSC complex has a robust mesonet from which an 18 year (1995-2012) warm-season convective wind climatology (WSCWC) was developed (Koermer 2017). While the frequency of downbursts in the area has been determined, the frequency at the individual tower locations has not. The 5-minute peak wind data from the WSCWC was analyzed to determine the geographic distribution of downburst frequency across Spaceport Florida. For this project a downburst was determined by the threshold of …

Methodology To Analyze Tropical Cyclone Intensity From Microwave Imagery, Matthew W. Perkins

Theses and Dissertations

Satellites with microwave remote sensing capabilities can be utilized to study atmospheric phenomena through high-level cloud cover (particularly cirrus), an advantage over visible and infrared bands, which only sense cloud tops. This unique capability makes microwave imagery ideal for studying the cloud structures of tropical cyclones (TCs) in detail, and relating these features to TC intensity. Techniques to estimate the intensity of TCs using infrared imagery, such as the Dvorak technique, have been used in TC forecasting for 40 years. However, due to the inherent temporal limitations of microwave imagery, no such similar technique exists for the microwave spectrum. This …

Impacts Of Sub-Auroral Polarization Streams On High Frequency Operations As A Function Of Modeled Particle Energy Flux, Nathan D. Smith

Theses and Dissertations

Space weather events can cause irregularities within the ionosphere; in particular, this research examines sub-auroral polarization streams (SAPS), as their accompanying irregularities and effects can degrade high-frequency (HF) signal propagation. It is known that the strongest westerly current drifts delineating SAPS are associated with a deep ionospheric trough, which in turn contaminates HF data with clutter from the non-standard ionosphere. Having a methodology to track and identify these occurrences on current computational architecture would provide operators enhanced situational awareness in knowing to expect degradation in HF processes. This study has discovered a weak, yet significant, exponentially decaying correlation between maximum …

Evaluation Of A Cloud Detection Technique Using Spatial And Radiometric Thresholds For Near Infrared Satellite Imagery, William J. Graff

Theses and Dissertations

Knowledge of cloud location in near infrared (NIR) imagery is of interest to the meteorological community given the wavelengths greater spatial resolution compared to longwave infrared and its potential nighttime applications. This method consists of an algorithm that can be employed by multiple instrument platforms. It analyzes changes between satellite image radiances and a seasonal synthetic background radiance image. The NIR sensor bands of the Sentinel-2 Multispectral Instrument (MSI) and Suomi National Polar-Orbiting Partnership (Suomi NPP) Visible Infrared Imaging Radiometer Suite (VIIRS) satellite instruments are used to evaluate the performance of a monochromatic change detection technique designed to locate areas …

Numerical Experiment Of Sediment Dynamics Over A Dredged Pit On The Louisiana Shelf, Nazanin Chaichitehrani

LSU Doctoral Dissertations

Sediment transport over Sandy Point dredge pit in the northern Gulf of Mexico was examined using field measurements and a finely resolved numerical model. Delft3D model with well-vetted computational grid and input parameters was used. Numerical experiments were performed to examine the effect of wind-generated waves, wind-driven currents and their interaction on sediment dynamics in our study area during a cold front in November 2014 and fair-weather conditions between July and August of 2015. Sediment dispersal from the lower Mississippi River, sediment resuspension, transport and deposition with high spatial and temporal resolution were simulated. A reliable satellite-derived near-surface suspended particulate …

Reconstructing Historical Hurricane Tracks In The Atlantic Basin: Three Case Studies From The 1840s, Emily L. Cerrito

USF Tampa Graduate Theses and Dissertations

Analyzing past tropical cyclone activity enables researchers to recognize patterns of hurricane variability, estimate hurricane return periods, and assess local risk to future storms. This paleotempestology study used original primary data to make the historical record as comprehensive and accurate as possible for three major hurricanes: October 1844, October 1846, and September 1848. This thesis presents the reconstructed storm tracks, assesses the societal impacts, and evaluates the storm intensity of these three major hurricanes for the eastern U.S. and Cuba. The data utilized in this study include ship logbooks, newspapers, diaries, and instrumental meteorological records. A geographic information system (GIS) …

Data From: Polar Topside Ionosphere During Geomagnetic Storms: Comparison Of Isis-Ii With Tdim, Jan J. Sojka, Dan Rice, Michael David, Robert W. Schunk, Robert Benson, H. G. James

Browse all Datasets

Output files from runs of the TDIM ionospheric model used for calculations and electron density profiles from ISIS-II and TDIM used in figures in the article in Radio Science.

Ultrahigh Resolution Ft-Icr Ms Data For Biomass Burning Emissions-Influenced Fog And Aerosol From The Po Valley, Matthew Brege, Lynn Mazzoleni

Department of Chemistry Publications

This dataset and the methods used to obtain it were described in "Molecular insights on aging and aqueous phase processing from ambient biomass burning emissions-influenced Po Valley fog and aerosol” submitted to Atmospheric Chemistry and Physics in March of 2018. Briefly, two samples of ambient fog water and two samples of ambient aerosol collected in the Po Valley (Italy) during the 2013 Supersito field campaign were analyzed using negative mode electrospray ionization Fourier transform ion cyclotron mass spectrometry (FT-ICR MS). The extent of “fresh” vs. “aged” biomass burning influence was estimated prior to FT-ICR MS analysis using proton nuclear magnetic …

Ceilometer Measurements From The University Of Western Ontario Of Smoke From The Extraordinary Fires Of 2017 In Western Canada, Achini J K Abayakoon Ms.

Western Research Forum

Background:

The summer of 2017 saw many fires in Western Canada. Smoke from these fires was transported by winds over to London and was measured using a Lufft CHM15k ceilometer which was installed at the Cronyn Observatory of The University of Western Ontario.

Methods:

The cloud base height can be calculated by the time taken for the backscatter signal to reach the transmitter while the backscatter effects can be used to determine the atmospheric structure using the principle of light detection and ranging (LiDAR).

Results:

Smoke particle concentrations over London, Ontario were observed within 72 hours of the fires taking …

Precipitation Extremes In Dynamically Downscaled Climate Scenarios Over The Greater Horn Of Africa, Andualem Shiferaw, Tsegaye Tadesse, Clinton M. Rowe, Robert Oglesby

National Drought Mitigation Center: Faculty Publications

This study first assesses the performance of regional climate models in the Coordinated Regional Climate Downscaling Experiment (CORDEX) in reproducing observed extreme precipitation indices over the Greater Horn of Africa (GHA) region during 1989–2005. The study then assesses projected changes in these extremes during 2069–2098 compared to 1976–2005. The Regional Climate Model (RCM) simulations are made using two RCMs, with large-scale forcing from four CMIP5 Global limate Models(GCMs) under two Representative Concentration Pathways (RCP4.5 and RCP8.5). We found that RCM simulations have reasonably captured observed patterns of moderate precipitation extreme indices (MPEI). Pattern correlation coefficients between simulated and observed MPEI …

Irrigated Agriculture And Future Climate Change Effects On Groundwater Recharge, Northern High Plains Aquifer, Usa, Zachary H. Lauffenburger, Jason J. Gurdak, Chris Hobza, Duane Woodward

United States Geological Survey: Staff Publications

Understanding the controls of agriculture and climate change on recharge rates is critically important to develop appropriate sustainable management plans for groundwater resources and coupled irrigated agricultural systems. In this study, several physical (total potential (ψT) time series) and chemical tracer and dating (3H, Cl−, Br−, CFCs, SF6, and 3H/3He) methods were used to quantify diffuse recharge rates beneath two rangeland sites and irrigation recharge rates beneath two irrigated corn sites along an east-west (wet-dry) transect of the northern High Plains aquifer, Platte River Basin, central Nebraska. The field-based recharge estimates and historical climate were used to calibrate site-specific Hydrus-1D …

Spatio-Temporal Pattern Estimation Of Pm2.5 In Beijing-Tianjin-Hebei Region Based On Modis Aod And Meteorological Data Using The Back Propagation Neural Network, Xialing Ni, Chunxiang Cao, Yuke Zhou, Xianghui Cui, Ramesh Singh

Mathematics, Physics, and Computer Science Faculty Articles and Research

With the economic growth and increasing urbanization in the last three decades, the air quality over China has continuously degraded, which poses a great threat to human health. The concentration of fine particulate matter (PM2.5) directly affects the mortality of people living in the polluted areas where air quality is poor. The Beijing-Tianjin-Hebei (BTH) region, one of the well organized urban regions in northern China, has suffered with poor air quality and atmospheric pollution due to recent growth of the industrial sector and vehicle emissions. In the present study, we used the back propagation neural network model approach to estimate …

Extreme Precipitation Events, Impacts, Trends And Projections For Indiana, Sam Lashley

Purdue Road School

The National Weather Service is working with core partners to build a Weather Ready Nation for present and future generations by taking advanced action against the devastating impacts of extreme weather events, including extreme precipitation and flooding. One way in which this can be accomplished is by studying trends in historical weather data and applying what we learn to future mitigation efforts. The goal is to gain a better understanding of the magnitude and impacts that future extreme precipitation events may have on local infrastructure.

This presentation will review extreme rainfall and flooding events that have occurred across Indiana along …

Weather And Climate Summary And Forecast: March 2018 Report, Gregory V. Jones

Linfield University Wine Studies Reports

This report provides a summary of the weather and climate forecast for March 2018. It includes forecast information specific to the Pacific Northwest and the western United States, as well as forecast information for other portions of the United States and abroad.

Gov. Ralph Northham Discusses Offshore Drilling At Blue Planet Forum, Betsy Hnath

News Items

No abstract provided.

Interlaboratory Comparison Of Δ13c And Δd Measurements Of Atmospheric Ch4 For Combined Use Of Data Sets From Different Laboratories, Taku Umezawa, Carl Brenninkmeijer, Thomas Röckmann, Carina Van Der Veen, Stanley C. Tyler, Ryo Fujita, Shinji Morimoto, Shuji Aoki, Todd Sowers, Jochen Schmitt, Michael Bock, Jonas Beck, Hubertus Fischer, Sylvia E. Michel, Bruce H. Vaughn, John B. Miller, James W.C. White, Gordon Brailsford, Hinrich Schaefer, Peter Sperlich, Willi A. Brand, Michael Rothe, Thomas Blunier, David Lowry, Rebecca E. Fisher, Euan G. Nisbet, Andrew L. Rice, Peter Bergamaschi, Cordelia Veidt, Ingeborg Levin

Physics Faculty Publications and Presentations

We report results from a worldwide interlaboratory comparison of samples among laboratories that measure (or measured) stable carbon and hydrogen isotope ratios of atmospheric CH₄ (δ¹³C-CH₄ and δD-CH₄). The offsets among the laboratories are larger than the measurement reproducibility of individual laboratories. To disentangle plausible measurement offsets, we evaluated and critically assessed a large number of intercomparison results, some of which have been documented previously in the literature. The results indicate significant offsets of δ¹³C-CH₄ and δD- CH₄ measurements among data sets reported from different laboratories; the differences among laboratories …

Approaches To Communicating Flooding Information In Hampton Roads: Results From Surveys Of Local Government Staff, Ashley M. Gordon, Michelle Covi

Presentations, Lectures, Posters, Reports

The objectives of this report are to identify current communication strategies regarding coastal flooding and present opportunities for improvement and collaboration within the Hampton Roads region. The Hampton Roads Planning District Commission partnered with Old Dominion University to design two surveys of local government staff, the first regarding flooding outreach and the second regarding flooding notification methods. This report summarizes the results of each survey and synthesizes challenges described by respondents. Opportunities and resources, including local initiatives and guides developed by federal agencies and emergency notification providers, are highlighted to assist local government staff in addressing challenges related to flooding …

2018 March - Tennessee Monthly Climate Report, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Monthly Reports

No abstract provided.

Umphlett Qci March 2018, Natalie Umphlett

High Plains Regional Climate Center: Staff Publications

Highlights for the Basin

Temperature and Precipitation Anomalies

Mountain Snowpack

Enhanced Fire Activity During Winter

Utilities Impacted by Extreme Cold

3-Month Precipitation and Temperature Outlooks

Winter Drought Conditions and Outlook