Atmospheric Sciences Commons^™

A Comparison Of Sporadic-E Occurrence Rates Using Gps Radio Occultation And Ionosonde Measurements, Rodney Carmona, Omar A. Nava, Eugene V. Dao, Daniel J. Emmons

Faculty Publications

Sporadic-E (E_s) occurrence rates from Global Position Satellite radio occultation (GPS-RO) measurements have shown to vary by a factor of five between studies, motivating the need for a comparison with ground-based measurements. In an attempt to find accurate GPS-RO techniques for detecting E_s formation, occurrence rates derived using five previously developed GPS-RO techniques are compared to ionosonde measurements over an eight-year period from 2010–2017. GPS-RO measurements within 170 km of a ionosonde site are used to calculate E_s occurrence rates and compared to the ground-truth ionosonde measurements. The techniques are compared individually for each ionosonde site …

Inverse Modeling Of Atmospheric Ch4 And Δ13C-Ch4 Measurements From Surface Observation Sites To Understand Trends In Global Methane Emissions Over More Than Three Decades, Sayantani Karmakar

Dissertations and Theses

Methane (CH₄) is the second most important greenhouse gas with a radiative forcing of 0.97 W/m² including both direct and indirect effects and a global warming potential of 28 over a 100-year time horizon. Unlike CO₂ whose rate of growth in the atmosphere has remained positive and increased in recent decades, the behavior of atmospheric methane is considerably more complex and is much less understood on account of the spatiotemporal variability of its emissions which include biogenic (e.g., wetlands, ruminants, rice agriculture), thermogenic (fossil fuels), and pyrogenic (i.e., biomass burning) sources. After sustained growth during most …

The Source Of Auroral Omegas, Heidi K. Nykyri, J.M. Weygand, Mostafa El-Alaoui

Publications

The auroral wave-like structures called “omega bands” appear within the post-midnight sector auroral oval with shapes resembling the Greek letter omega, and are typically associated with the recovery phase of substorms. Prior work and MHD simulations suggest both high speed earthward flows and postmidnight flow shears are possible omega band source mechanisms. However, what produces omega bands is not well understood. It is most likely that the paucity of concurrent magnetospheric data has limited our ability to understand fully the mechanism responsible for the generation of the omega bands. We have identified about 263 auroral omegas in seven different THEMIS …

A Greenhouse Gas Emissions Inventory For Nebraska: Livestock And Coal Loom Large, Eric R. Holley, Adam Liska

Adam Liska Papers

Mitigation of climate change requires the systematic identification and cataloging of emissions sources at city, state, and national levels. In this study, an inventory of annual greenhouse gas emissions from the state of Nebraska was created based on industry data, and emissions inventories were completed each year from 1990 to 2016. Nebraska’s net emissions were found to increase from 56.2 million metric tons of carbon dioxide equivalents (MMtCO₂e) in 1990 to 87.4 MMtCO₂e in 2016. Agriculture was found to be the sector with the most emissions (36 MMtCO₂e) followed by electricity generation (21 MMtCO …

Temperature Trends In The Northeastern United States From 1950-2018, Emanuel Eagle

Environmental Studies Honors Papers

No abstract provided.

Horizontal Air Mass: Solutions For Fermi Questions, November 2022, John Adam

Mathematics & Statistics Faculty Publications

No abstract provided.

Indoor Air Quality Through The Lens Of Outdoor Atmospheric Chemistry, Jonathan P.D. Abbatt, Douglas B. Collins

Faculty Contributions to Books

Outdoor atmospheric chemistry and air quality have been the topic of research that intensified in earnest around the mid-20^th century, while indoor air quality research has only been a key focus of chemical researchers over the last 30 years. Examining practices and approaches employed in the outdoor atmospheric chemistry research enterprise provides an additional viewpoint from which we can chart new paths to increase scientific understanding of indoor chemistry. This chapter explores our understanding of primary chemical sources, homogeneous and multiphase reactivity, gas-surface partitioning, and the coupling between the chemistry and dynamics of indoor air through the lens of …

Simulation Of Urban Heat Island During A High-Heat Event Using Wrf Urban Canopy Models: A Case Study For Metro Manila, Ronald Gil Joy P. Bilang, Ariel C. Blanco, Justine Ace S. Santos, Lyndon Mark P. Olaguera

Physics Faculty Publications

This present study aims to determine the performance of using the Weather Research and Forecasting (WRF) Model, coupled with the urban canopy models (UCMs), in simulating the 2 m air temperature and 2 m relative humidity in Metro Manila. The simulation was performed during a high heat event on 22–29 April 2018, which coincided with the dry season in the Philippines. The four urban canopy model options that were used in this study include, the bulk (no urban), SLUCM, BEP, and BEM. The results of the simulations were compared with the hourly observations from three weather stations over Metro Manila …

Dynamic Impacts Of Hadley Circulation On Saharan Desert Warming Amplification, Alejandro Manuel Ayala

Legacy Theses & Dissertations (2009 - 2024)

Changes in temperature due to climate change are not spatially uniform, and deserts and other drylands, which are greatly underrepresented in climate studies, are warming at a much faster rate than much of the globe with increasing concentrations of greenhouse gases. This strong warming amplification over deserts, termed Desert Amplification (DA), is most pronounced over the world’s largest and driest Sahara Desert and the Arabian Peninsula. The Sahara and Arabian deserts are formed in the subtropical subsiding branch of the Hadley Circulation (HC) and so the changes in large-scale subsidence associated with adiabatic heating could impact the DA dynamically. While …

Spatiotemporal Variability Of Snow Depth On Arctic Sea Ice In Cmip6 Models And Satellite Data, Shengzhe Chen

Legacy Theses & Dissertations (2009 - 2024)

The Arctic has experienced rapid environmental changes in recent decades. Motivated by the important role of snow over sea ice in influencing Arctic climate variability and change, this dissertation aims to improve our knowledge of spatiotemporal variability of snow depth and processes over Arctic sea ice in the observations and model simulations.First, we evaluate snow depth over Arctic sea ice during 1993–2014 simulated by the models from the Coupled Model Intercomparison Project phase 6 (CMIP6) against recent satellite retrievals. The CMIP6 models capture some aspects of the observed snow depth climatology and variability. The observed variability lies in the middle …

Understanding Changes In Precipitation, Wildfires, And Possible Governing Factors Over Central Equatorial Africa, Yan Jiang

Legacy Theses & Dissertations (2009 - 2024)

Tropical rainforests are global epicenters of biodiversity and modulators of climate. A long-term drying trend has occurred in the Congo Basin since the 1980s and this raises great concerns for sustaining the Congolese rainforest and local rain-fed agriculture. Motivated by documented rainfall changes and the need to improve understanding of main factors influencing precipitation variability and changes in Central Equatorial Africa (CEA), this dissertation conducts synthesized studies on 1) quantifying variations in precipitation seasonality by focusing on dry season duration, 2) estimating cascading wildfire risks associated with changes in precipitation patterns, and estimating impacts of 3) the tropical Indian Ocean …

The Mountain Gap Wind Of The Isthmus Of Tehuantepec And Its Impact On Tropical Cyclogenesis In The Eastern Pacific, Adolfo Lugo Rios

Legacy Theses & Dissertations (2009 - 2024)

In this dissertation we research two aspects of the mountain gap wind northerlies of the Isthmus of Tehuantepec in Southern Mexico. The causes of extreme gap wind northerlies, emphasizing the causes by tropical weather systems, like easterly waves troughs or hurricanes, and the impacts of an extreme gap wind events on tropical cyclogenesis.Through the use of an index to diagnose the mountain gap wind strength, its evolution through the year and the mechanisms leading to extreme mountain gap winds was highlighted. The index revealed that the gap wind is strongly related to high surface pressure anomalies over the GoM throughout …

A Synoptic-Dynamic Analysis Of The Structure And Evolution Of Persistent North Pacific Wintertime Ridge Regimes, Tyler Christopher Leicht

Legacy Theses & Dissertations (2009 - 2024)

Along the west coast of North America (NA), a majority of the precipitation for the entire year falls during winter as a result of approximately a dozen cyclones or atmospheric rivers. However, persistent upper-level ridges can prevent the occurrence of wintertime precipitation events and lead to extended drought, significant water shortages, and adverse economy-wide impacts for major population centers in California. An increased understanding of the dynamical and thermodynamical processes that govern upper-level ridge formation, persistence, and dissipation during the rainy season along western NA would allow decision makers to better manage water resources and motivates this thesis. Persistent upper-level …

The Surface Heating Efficiency Of Atmospheric Energy Flux Events During Arctic Winter, Christopher Joseph Cardinale

Legacy Theses & Dissertations (2009 - 2024)

The flux of moist static energy (MSE) into the polar regions plays a key role in the energy budget and climate of the polar regions. While usually studied from a vertically integrated perspective (Fwall), this dissertation examines its vertical structure, using the NASA-MERRA-2 reanalysis to compute climatological and anomalous fluxes of sensible, latent, and potential energy across 70◦N and 65◦S. This dissertation applies an energy budget analysis to winter-season synoptic periods of increased tropospheric (Ftrop) and stratospheric (Fstrat) energy flux convergence events and examines the processes that drive Arctic anoma lous surface warming and sea ice loss during Ftrop events. …

New York City Micronet : Comprehensive Site Metadata And Classifications And Characteristics Of The Urban Heat Island, Ashley Williamson

Legacy Theses & Dissertations (2009 - 2024)

The New York City Micronet (NYC Micronet), comprised of 17 stations, was installed in the Fall of 2020 for the purpose of long-term monitoring of climate change, and to provide support to utility operations for Consolidated Edison, Inc. (Con Edison). There are five additional standard NYS Mesonet stations located in NYC installed in late 2017. Co-located at the standard stations are three flux, and three profiler stations from sub-networks within the NYS Mesonet. With 22 different locations collecting 5-minute averaged data, this network becomes the highest spatial and temporal resolution urban meteorological network (UMN) of this quality in NYC. This …

The Mountain Gap Wind Of The Isthmus Of Tehuantepec And Its Impact On Tropical Cyclogenesis In The Eastern Pacific, Adolfo Lugo Rios

Atmospheric and Environmental Sciences Theses and Dissertations

In this dissertation we research two aspects of the mountain gap wind northerlies of the Isthmus of Tehuantepec in Southern Mexico. The causes of extreme gap wind northerlies, emphasizing the causes by tropical weather systems, like easterly waves troughs or hurricanes, and the impacts of an extreme gap wind events on tropical cyclogenesis.

Through the use of an index to diagnose the mountain gap wind strength, its evolution through the year and the mechanisms leading to extreme mountain gap winds was highlighted. The index revealed that the gap wind is strongly related to high surface pressure anomalies over the GoM …

The Urban Heat Island Of Bengaluru, India : Characteristics, Trends, And Mechanisms, Heather Samantha Sussman

Legacy Theses & Dissertations (2009 - 2024)

The urban heat island (UHI) effect refers to how urban surfaces tend to be warmer than nearby non-urban areas due to less vegetation and other processes. UHIs can increase the risk of heat and respiratory illnesses. Since every city is unique, UHIs should be studied on a local-scale. One particular city that has not had its UHI comprehensively evaluated is Bengaluru, India. Bengaluru was once known as the “Garden City” of India due to a wide presence of gardens and public parks, but is now known as the “Silicon City” of India due to the overwhelming presence of the information …

Droughtscape, Winter 2022, National Drought Mitigation Center

DroughtScape: Quarterly Newsletter of the National Drought Mitigation Center (2007–2023)

DroughtScape, Winter 2022

Stubborn Aerosol: Why Particulate Mass Concentrations Do Not Drop During The Wet Season In Metro Manila, Philippines, Miguel Ricardo A. Hilario, Paola Angela Bañaga, Grace Betito, Rachel A. Braun, Maria Obiminda L. Cambaliza, Melliza Templonuevo Cruz, Genevieve Rose Lorenzo, Alexander B. Macdonald, Preciosa Corazon Pabroa, James Bernard Simpas

SOSE Affiliate: Manila Observatory

Wet scavenging is the most important sink for particulate matter (PM) and is expected to decrease PM concentrations in the wet season. However, Metro Manila, Philippines has highly similar PM mass across seasons despite large differences in seasonal rainfall. It is important to identify factors contributing to seasonally consistent PM mass as these may be present in similar developing megacities besides Metro Manila, leading to PM accumulation and posing significant health risks. We use size-resolved aerosol composition, aerosol optical depth, and meteorological data to reveal that the seasonally consistent PM mass in Metro Manila is due to (1) opposing seasonal …

Nrlmsis 2.1: An Empirical Model Of Nitric Oxide Incorporated Into Msis, J. T. Emmert, M. Jones Jr., D. E. Siskind, D. P. Drob, J. M. Picone, M. H. Stevens, S. M. Bailey, S. Bender, P. F. Bernath, B. Funke, M. E. Hervig, K. Pérot

Chemistry & Biochemistry Faculty Publications

We have developed an empirical model of nitric oxide (NO) number density at altitudes from ∼73 km to the exobase, as a function of altitude, latitude, day of year, solar zenith angle, solar activity, and geomagnetic activity. The model is part of the NRLMSIS® 2.1 empirical model of atmospheric temperature and species densities; this upgrade to NRLMSIS 2.0 consists solely of the addition of NO. MSIS 2.1 assimilates observations from six space-based instruments: UARS/HALOE, SNOE, Envisat/MIPAS, ACE/FTS, Odin/SMR, and AIM/SOFIE. We additionally evaluated the new model against independent extant NO data sets. In this paper, we describe the formulation and …