Atmospheric Sciences Commons^™

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 …

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 …

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 …

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

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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 …

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 …

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

News Items

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

Evaluation Of Nocturnal Convective Precipitation Over The Great Plains Using Reanalysis Data And A Wrf-Based Regional Climate Model, Xu Deng

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

This study aims to analyze what processes are mainly responsible for nocturnal convective precipitation during the 1991-2000 period for May-June-July over the Great Plains. Firstly, based on the Weather Research and Forecasting model (WRF) coupled with the NCAR Community Land Model (CLM) and the North American Regional Reanalysis (NARR) reanalysis data, the simulations of the diurnal cycles of LLJ and the convective precipitation are examined. Then, the LLJ-related moisture transport is evaluated since the moisture supply is critical for the development of the heavy rainfall. Results show that the WRF model fails to simulate the nocturnal peak rainfall shown in …

Forecasting Lightning Initiation Utilizing Dual-Polarization Radar Parameters Over Washington, D.C., Sarah A. Olsen

Theses and Dissertations

Accurate forecasts of thunderstorms are vital to space launch, aviation, and public safety. Prior studies by Woodard (2011), Thurmond (2014), and Travis (2015) show that dual-polarization radar can be utilized to identify the presence of hydrometeors necessary for cloud charging. These studies emphasized that a combination of radar reflectivity (Z) and differential reflectivity (Z_DR) predictors have the potential to improve forecast skill of lightning initiation over methods that rely on Z alone (Roeder and Pinder, 1998; Yang and King, 2010). Travis (2015) discovered two parameters, when used together, produced the best results: Z ≥ 36.5 dBZ and ZDR …

Ultrahigh Resolution Ft-Icr Ms Data Of Long-Range Transported Free Tropospheric Aerosol Collected At The Pico Mountain Observatory In The Azores, Simeon K. Schum, Lynn Mazzoleni

Department of Chemistry Publications

This dataset and the methods used to obtain it were described in “Molecular and physical characteristics of aerosol at a remote marine free troposphere site: Implications for atmospheric aging” submitted to Atmospheric Chemistry and Physics in February 2018. Briefly, three long-range transported organic aerosol samples were analyzed using negative mode electrospray ionization Fourier transform ion cyclotron mass spectrometry (FT-ICR MS) with a mass resolving power of 400,000 (defined at m/z 400). FLEXPART retroplume simulations indicated that two of the samples (PMO-1 & PMO-3) were influenced by North American wildfire emissions transported in the free troposphere and one (PMO-2) by North …

Sea Level Rise Moving Faster Than Scientists Initially Thought, Noell Saunders

News Items

No abstract provided.

Odu-Led St. Vincent Workshop Explored Ocean's Role In Caribbean-Based U.N. Sustainable Development Initiative, News @ Odu

News Items

No abstract provided.

Caves As Observatories For Atmospheric Thermal Tides: An Example From Ascunsă Cave, Romania, Virgil Drăgușin, Laura Tîrlă, Nicoleta Cadicheanu, Vasile Ersek, Ionuț Mirea

International Journal of Speleology

As part of a microclimate study at Ascunsă Cave, Romania, we used Gemini Tinytag Plus 2 data loggers to record cave air temperature variability. At one of the monitoring points we recognized the presence of semidiurnal cycles on the order of a few thousands of a degree Celsius that could be produced under the influence of the semidiurnal tidal components of the Sun (S₂) or the Moon (M₂). Using a Gemini Tinytag Plus 2 data logger with an external probe we measured core rock temperature and showed that it does not influence the cave air temperature …

Scientometric Study Of Research Productivity Of Aries, Nainital, Satish Kumar

Library Philosophy and Practice (e-journal)

This paper describes scientometric study of research productivity of Scientists of Aryabhatta Research Institute of Observational Sciences (ARIES), Nainital. The purpose of this study is to evaluate the research performance of ARIES, Nainital. For this study, the data is collected from Web of Science (WoS) bibliographical database for the period of 15 years from 2001-2015 and analyzed. 574 research paper has been published over 15 years of time in which 510 research publications are in referred journals and 64 research publications are in conferences, symposiums, bulletins etc. This paper identifies the scientists of ARIES those are active; the areas in …

Mesospheric Densities And Temperatures Derived From 11 Years Of Data Acquired With The Rayleigh-Scatter Lidar At The Atmospheric Lidar Observatory At Utah State University, Vincent B. Wickwar, Joshua P. Herron

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Frequent observations were carried out with the Rayleigh-scatter lidar at Utah State University’s Atmospheric Lidar Observatory (41.742572° N, 111.808273° W, and 1466 m) from August 1993 through December 2004. Of 964 nights observed, a total of 839 nights were judged good for deriving temperatures. These 839 were reduced to obtain all-night relative neutral densities and absolute temperatures. These results extend from 45 to ≤ 95 km, thereby covering the mesosphere. This netCDF file starts by giving the number of nights included in the file. For each night, the netCDF file then provides defining parameters and derived profiles, as defined below. …

The Fire And Smoke Model Evaluation Experiment - A Plan For Integrated, Large Fire-Atmosphere Field Campaigns, Susan Prichard, Roger Ottmar, Nancy H. F. French, Kirk Baker, Tim Brown, Craig Clements, Danielle Tanzer, Et. Al.

Michigan Tech Research Institute Publications

The Fire and Smoke Model Evaluation Experiment (FASMEE) is designed to collect integrated observations from large wildland fires and provide evaluation datasets for new models and operational systems. Wildland fire, smoke dispersion, and atmospheric chemistry models have become more sophisticated, and next-generation operational models will require evaluation datasets that are coordinated and comprehensive for their evaluation and advancement. Integrated measurements are required, including ground-based observations of fuels and fire behavior, estimates of fire-emitted heat and emissions fluxes, and observations of near-source micrometeorology, plume properties, smoke dispersion, and atmospheric chemistry. To address these requirements the FASMEE campaign design includes a study …

Effects Of Projected Changes In Wind, Atmospheric Temperature, And Freshwater Inflow On The Ross Sea, Michael S. Dinniman, John M. Klinck, Eileen E. Hofmann, Walker O. Smith Jr.

CCPO Publications

A 5-km horizontal resolution regional ocean-sea ice-ice shelf model of the Ross Sea is used to examine the effects of changes in wind strength, air temperature, and increased meltwater input on the formation of high-salinity shelf water (HSSW), on-shelf transport and vertical mixing of Circumpolar Deep Water (CDW) and its transformation into modified CDW (MCDW), and basal melt of the Ross Ice Shelf (RIS). A 20% increase in wind speed, with no other atmospheric changes, reduced summer sea ice minimum area by 20%, opposite the observed trend of the past three decades. Increased winds with spatially uniform, reduced atmospheric temperatures …

Expanding Spheres: Atoms To Earth, Local To Global, Science To Society, Sarah Green

Distinguished Lecture Series

Best case scenario. Worst case scenario. Sarah Green talks about the human impacts of climate change and responding to those changes on local and global scales. Green, a professor in both the Department of Chemistry and the Great Lakes Research Center at Michigan Technological University, presented the Spring 2018 Distinguished Lecture at the Michigan Tech Research Forum. Her lecture, Expanding Spheres: Atoms to Earth, Local to Global, Science to Society, was Thursday, February 15, 2018.

A Comparison Of Small- And Medium-Scale Gravity Wave Interactions In The Linear And Nonlinear Limits, C. J. Heale, J. B. Snively

Publications

A 2-D numerical model is used to compare interactions between small-scale (SS) (25 km horizontal wavelength, 10 min period) and medium-scale (MS, 250 km horizontal wavelength, 90 min period) gravity waves (GWs) in the Mesosphere and Lower Thermosphere within three different limits. First, the MS wave is specified as a static, horizontally homogeneous ambient atmospheric feature; second, a linear interaction is investigated between excited, time-dependent SS and MS waves, and third, a fully nonlinear interaction at finite amplitudes is considered. It is found that the finite-amplitude wave interactions can cause SS wave breaking aligned with the phase fronts of the …

Odu Colleges Prepare To Collaborate On Second Arctic Research Expedition, Roger Njunge

News Items

No abstract provided.

Civil Engineering Ph.D. Student Puts Virginia Sea Grant Graduate Fellowship To Work On Living Shorelines, Keith Pierce

News Items

No abstract provided.

2017 Costliest Year Ever For Weather-Related Disasters, Betsy Hnath

News Items

No abstract provided.

Estimating Live Fuel Moisture From Modis Satellite Data For Wildfire Danger Assessment In Southern California Usa, Boksoon Myoung, Seung Hee Kim, Son V. Nghiem, Shenyue Jia, Kristen Whitney, Menas Kafatos

Mathematics, Physics, and Computer Science Faculty Articles and Research

The goal of the research reported here is to assess the capability of satellite vegetation indices from the Moderate Resolution Imaging Spectroradiometer onboard both Terra and Aqua satellites, in order to replicate live fuel moisture content of Southern California chaparral ecosystems. We compared seasonal and interannual characteristics of in-situ live fuel moisture with satellite vegetation indices that were averaged over different radial extents around each live fuel moisture observation site. The highest correlations are found using the Aqua Enhanced Vegetation Index for a radius of 10 km, independently verifying the validity of in-situ live fuel moisture measurements over a large …

Unexpected Occurrence Of Mesospheric Frontal Gravity Wave Events Over South Pole (90°S), Pierre-Dominique Pautet, Michael J. Taylor, J. B. Snively, Christina Solorio

Publications

Since 2010, Utah State University has operated an infrared Advanced Mesospheric Temperature Mapper at the Amundsen–Scott South Pole station to investigate the upper atmosphere dynamics and temperature deep within the vortex. A surprising number of “frontal” gravity wave events (86) were recorded in the mesospheric OH(3,1) band intensity and rotational temperature images (typical altitude of ~87 km) during four austral winters (2012–2015). These events are gravity waves (GWs) characterized by a sharp leading wave front followed by a quasi-monochromatic wave train that grows with time. A particular subset of frontal gravity wave events has been identified in the past (Dewan …

Evolution Of The Maximum Upper Level Divergence Field In Gulf-Atlantic Tropical Cyclogenesis, Sara A. Ates

LSU Master's Theses

Upper-level (horizontal) divergence (ULD) is an important variable in tropical weather systems. As part of the circulation within a tropical cyclone (TC), it carries air in the upper troposphere away from the center of circulation (COC). To date, most research assumes the 200 hPa pressure level (approximately 12 km, varying with latitude and time of year) as the height for maximum ULD in a TC, possibly because weather observation at the 200 hPa level by radiosonde have remained mandatory for aviation purposes. The more recent availability of gridded, high-spatial-resolution, global “reanalysis” data at multiple levels, along with improvements in spatial …

Coastal Land-Air Sea Interaction: June 13th 2016 Rhib Momentum Flux Observations, David G. Ortiz-Suslow, Brian K. Haus, Neil J. Williams, Hans C. Graber, Jamie H. Macmahan

Supplementary Data and Tools

The dataset collected here represents the processed and quality-controlled information used in the analysis and presentation of the manuscript, “Observations of Air-Sea Momentum Flux Variability across the Inner Shelf” by the authors listed above, which is published by AGU in the Journal of Geophysical Research-Oceans. Unless specifically noted in the data file’s header/metadata information or in this document, all of the data contained within this set was collected from instrumentation mounted aboard the rigid-hull inflatable boat (RHIB) deployed as part of the CLASI field study on the June 13, 2016. These measurements were made within Monterey Bay directly offshore of …