Atmospheric Sciences Commons^™

Estimating Methane Emissions From Biological And Fossil-Fuel Sources In The San Francisco Bay Area, Seongeun Jeong, Xinguang Cui, Donald Blake, Ben Miller, Stephen Montzka, Arlyn Andrews, Abhinav Guha, Philip Martien, Ray Bambha, Brian Lafranchi, Hope Michelsen, Craig Clements, Pierre Glaize, Marc Fischer

Faculty Publications, Meteorology and Climate Science

We present the first sector-specific analysis of methane (CH4) emissions from the San Francisco Bay Area (SFBA) using CH4 and volatile organic compound (VOC) measurements from six sites during September – December 2015. We apply a hierarchical Bayesian inversion to separate the biological from fossil-fuel (natural gas and petroleum) sources using the measurements of CH4 and selected VOCs, a source-specific 1 km CH4 emission model, and an atmospheric transport model. We estimate that SFBA CH4 emissions are 166–289 Gg CH4/yr (at 95% confidence), 1.3–2.3 times higher than a recent inventory with much of the underestimation from landfill. Including the VOCs, …

Application Of Recurrent Neural Networks For Drought Projections In California, J. A. Le, Hesham El-Askary, Mohamed Allali, Daniele C. Struppa

Mathematics, Physics, and Computer Science Faculty Articles and Research

We use recurrent neural networks (RNNs) to investigate the complex interactions between the long-term trend in dryness and a projected, short but intense, period of wetness due to the 2015-2016 El Niño. Although it was forecasted that this El Niño season would bring significant rainfall to the region, our long-term projections of the Palmer Z Index (PZI) showed a continuing drought trend, contrasting with the 1998-1999 El Niño event. RNN training considered PZI data during 1896-2006 that was validated against the 2006-2015 period to evaluate the potential of extreme precipitation forecast. We achieved a statistically significant correlation of 0.610 between …

Anisotropic Fluid Modeling Of Ionospheric Upflow: Effects Of Low‐Altitude Anisotropy And Thermospheric Winds, M. R. Burleigh, M. Zettergren

Publications

A new anisotropic fluid model is developed to describe ionospheric upflow responses to magnetospheric forcing by electric fields and broadband ELF waves at altitudes of 90–2500 km. This model is based on a bi‐Maxwellian ion distribution and solves time‐dependent, nonlinear equations of conservation of mass, momentum, parallel energy, and perpendicular energy for six ion species important to E, F, and topside ionospheric regions. It includes chemical and collisional interactions with the neutral atmosphere, photoionization, and electron impact ionization. This model is used to examine differences between isotropic and anisotropic descriptions of ionospheric upflow driven by DC electric fields, …

Data From: Observing System Simulation Experiments For An Array Of Autonomous Biogeochemical Profiling Floats In The Southern Ocean, Igor Kamenkovich, Angelique Haza, Alison R. Gray, Carolina O. Dufour, Zulema Garraffo

Supplementary Data and Tools

Data in this collection is from Observation System Simulation Experiments (OSSEs) that were carried in support of the SOCCOM program. Synthetic profiles were extracted from model-simulated dissolved oxygen and inorganic carbon. Full maps were then reconstructed from these sparse datasets, using objective mapping. For description of the model and reconstruction method please see Kamenkovich, I., A. Haza, A. Gray, C. Dufour, and Z. Garraffo: "Observing System Simulation Experiments for an array of autonomous biogeochemical profiling floats in the Southern Ocean", Journal of Geophysical Research, DOI: 10.1002/2017JC012819

Improved Characterization And Analysis Strategies For Uv-Lif Bioaerosol Instrumentation: Lab And Field Application, Nicole Justine Savage

Electronic Theses and Dissertations

Atmospheric particles of biological origin, also referred to as bioaerosols or primary biological aerosol particles (PBAP), are important to various human health and environmental systems. There has been a recent steep increase in the frequency of published studies utilizing commercial instrumentation based on ultraviolet laser/light-induced fluorescence (UV-LIF), such as the WIBS (wideband integrated bioaerosol sensor), for bioaerosol detection both outdoors and in the built environment. Significant work over several decades supported the development of these technologies, but efforts to systematically characterize the operation of new commercial sensors has remained lacking. Specifically, there are gaps in the understanding of how different …

Quantification Of Airborne Fungal Spores Comparing Molecular Tracers Via Ion Chromatography And Uv-Lif Methods, Marie Ila Gosselin

Electronic Theses and Dissertations

Fungal spores represent an understudied subcategory of bioaerosols that can impact human health as pathogenic and allergenic particles. Fungal spores also have been shown to act as effective ice nuclei and giant cloud condensation nuclei in some cases. This has implications on the hydrological cycle on local and regional scales by impacting the formation and evolution of clouds and precipitation. The quantification of fungal spores has been limited in the past due to methods that were costly and that suffered from poor time resolution. The most commonly applied methods for airborne fungal spore analysis have traditionally included microscopy and culturing, …

New Particle Formation In The Mid-Latitude Upper Troposphere, Duncan Axisa

Electronic Theses and Dissertations

Primary aerosol production due to new particle formation (NPF) in the upper troposphere and the impact that this might have on cloud condensation nuclei (CCN) concentration can be of sufficient magnitude to contribute to the uncertainty in radiative forcing. This uncertainty affects our ability to estimate how sensitive the climate is to greenhouse gas emissions. Therefore, new particle formation must be accurately defined, parametrized and accounted for in models.

This research involved the deployment of instruments, data analysis and interpretation of particle formation events during the Mid-latitude Airborne Cirrus Properties Experiment (MACPEX) campaign. The approach combined field measurements and observations …

High Plains Regional Climate Center (Poster)

High Plains Regional Climate Center: Staff Publications

The HPRCC provides the public with several ways to access climate data and information. Whether via direct contact, website access, or through a subscription to one of HPRCC’s online services, users can acquire a variety of climate data products, such as: • Near Real-Time and Historical Climate Data • National and Regional Climate Data Maps • Agricultural Climate Products • Monthly, Quarterly, and Annual Regional Climate Summaries

Light-Induced Protein Nitration And Degradation With Hono Emission, Hannah Meusel, Yasin Elshorbany, Uwe Kuhn, Thorsten Bartels-Rausch, Kathrin Reinmuth, Christopher J. Kampf, Yafang Cheng

USF St. Petersburg Campus Faculty Publications

Proteins can be nitrated by air pollutants (NO2), enhancing their allergenic potential. This work provides insight into protein nitration and subsequent decomposition in the presence of solar radiation. We also investigated light-induced formation of nitrous acid (HONO) from protein surfaces that were nitrated either online with instantaneous gas-phase exposure to NO2 or offline by an efficient nitration agent (tetranitromethane, TNM). Bovine serum albumin (BSA) and ovalbumin (OVA) were used as model substances for proteins. Nitration degrees of about 1% were derived applying NO2 concentrations of 100 ppb under VIS=UV illuminated conditions, while simultaneous decomposition of (nitrated) proteins was also found …

Comparing Cmaq Forecasts With A Neural Network Forecast Model For Pm2.5 In New York, Samuel D. Lightstone, Fred Moshary, Barry Gross

Publications and Research

Human health is strongly affected by the concentration of fine particulate matter (PM2.5). The need to forecast unhealthy conditions has driven the development of Chemical Transport Models such as Community Multi-Scale Air Quality (CMAQ). These models attempt to simulate the complex dynamics of chemical transport by combined meteorology, emission inventories (EI’s), and gas/particle chemistry and dynamics. Ultimately, the goal is to establish useful forecasts that could provide vulnerable members of the population with warnings. In the simplest utilization, any forecast should focus on next day pollution levels, and should be provided by the end of the business day (5 p.m. …

A Model-Based Assessment Of Potential Impacts Of Man-Made Reservoirs On Precipitation, Jesse Winchester, Rezaul Mahmood, William Rodgers, Faisal Hossain, Eric Rappin, Joshua D. Durkee, Themis Chronis

High Plains Regional Climate Center: Staff Publications

Land-use land-cover change (LULCC) plays an important role in weather and climate systems. Human modifications of land cover include building reservoirs and thus creating artificial lakes for multipurpose use. In this research, the authors have completed a Weather Research and Forecasting (WRF) Model–based assessment of impacts of two large parallel lakes on precipitation. This area is located in the western part of the states of Kentucky and Tennessee and known as the Land between the Lakes (LBL). To determine the impacts, this study has replaced the lakes with grass, deciduous forests, and bare soil and conducted model simulations for three …

The Effect Of The Dry Line And Convective Initiation On Drought Evolution Over Oklahoma During The 2011 Drought, Paul X. Flanagan, Jeffrey B. Basara, Bradley G. Illston, Jason A. Otkin

High Plains Regional Climate Center: Staff Publications

Observations from the Oklahoma Mesonet and high resolution Weather Research and Forecasting model simulations were used to evaluate the effect that the dry line and large-scale atmospheric patterns had on drought evolution during 2011. Mesonet observations showed that a “dry” and “wet” pattern developed across Oklahoma due to anomalous atmospheric patterns. The location of the dry line varied due to this “dry” and “wet” pattern, with the average dry line location around 1.5∘ longitude further to the east than climatology.Model simulations were used to further quantify the impact of variable surface conditions on dry line evolution and convective initiation (CI) …

Droughtscape, Winter 2017, National Drought Mitigation Center

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

Contents

NDMC partners with Sioux tribes to build climate resiliency

Drought intensifies in some regions of U.S. in fall

Fire danger and sequoia deaths in third quarter

2016: Year in review

MENA region forums elicit

feedback from stakeholders

Tech pass-off in Tunisia

Midwest DEWS meetings build collaboration, relationships

Workshop links drought, socioeconomic impacts/p>

Drought center helps ranchers prepare for drought

Drought tourney in Nebraska goes low tech

Evaluating Hourly Rainfall Characteristics Over The U.S. Great Plains In Dynamically Downscaled Climate Model Simulations Using Nasa-Unified Wrf, Huikyo Lee, Duane E. Waliser, Robert Ferraro, Takamichi Iguchi, Christa D. Peters-Lidard, Baijun Tian, Paul C. Loikith, Daniel B. Wright

Geography Faculty Publications and Presentations

Accurate simulation of extreme precipitation events remains a challenge in climate models. This study utilizes hourly precipitation data from ground stations and satellite instruments to evaluate rainfall characteristics simulated by the NASA-Unified Weather Research and Forecasting (NU-WRF) regional climate model at horizontal resolutions of 4, 12, and 24 km over the Great Plains of the United States. We also examined the sensitivity of the simulated precipitation to different spectral nudging approaches and the cumulus parameterizations. The rainfall characteristics in the observations and simulations were defined as an hourly diurnal cycle of precipitation and a joint probability distribution function (JPDF) between …

Investigating The Atmospheric Production Of Perchlorate: Inference From Polar Ice Cores, Thomas S. Cox

Electronic Theses and Dissertations

Perchlorate (ClO₄) in the environment is of concern, because of potential health risks to humans, among other reasons. Evidence suggests that the majority of environmental perchlorate is formed in the atmosphere (likely in the stratosphere), in chemical processes involving ozone and stratospheric chlorine. A lack of knowledge in regards to the processes has resulted in a limited understanding of the environmental conditions and variables that influence perchlorate production and consequently perchlorate prevalence and variability in the environment. In this study, perchlorate was measured, using an established ion chromatography-­‐electrospray ionization-­‐tandem mass spectrometry (IC-­‐ESI-­‐ MS/MS) technique, in over 1,600 snowpit …

Quantification Of Urban Atmospheric Boundary Layer Greenhouse Gas Dry Mole Fraction Enhancements In The Dormant Season: Results From The Indianapolis Flux Experiment (Influx), Natasha Miles, Scott Richardson, Thomas Lauvaux, Kenneth J. Davis, Nikolay V. Balashov, Aijun Deng, Jocelyn Turnbull, Colm Sweeney, Kevin R. Gurney, Risa Patarasuk, Igor Razlivanov, Maria Obiminda L. Cambaliza, Paul B. Shepson

Physics Faculty Publications

We assess the detectability of city emissions via a tower-based greenhouse gas (GHG) network, as part of the Indianapolis Flux (INFLUX) experiment. By examining afternoon-averaged results from a network of carbon dioxide (CO2), methane (CH4), and carbon monoxide (CO) mole fraction measurements in Indianapolis, Indiana for 2011–2013, we quantify spatial and temporal patterns in urban atmospheric GHG dry mole fractions. The platform for these measurements is twelve communications towers spread across the metropolitan region, ranging in height from 39 to 136 m above ground level, and instrumented with cavity ring-down spectrometers. Nine of the sites were deployed as of January …

Upper Water Structure And Mixed Layer Depth In Tropical Waters: The Seats Station In The Northern South China Sea, Jen-Hua Tai, George T. F. Wong, Xiaoju Pan

OES Faculty Publications

The variability of the upper water hydrographic structure, the efficacy of the different schemes for estimating the mixed layer depth (MLD), the inter-comparability estimation of the MLDs and diurnal and intra-annual MLD climatology in the tropical waters in the northern South China Sea were accessed in 702 depth-profiles of potential temperature (θ) and salinity collected in 64 cruises between 17.5 and 18.5°N and 115.3 and 116.3°E from 1997 to 2013. The hydrographic structure may be subdivided into three principal types: the classical type, with quasi-isopycnal surface mixed layer followed by an abrupt increase in the depth-gradient in θ and potential …

Studies Of Direct Solar Irradiance And Aerosol Optical Depth Using An Mfrsr And A Microtop Sunphotometer In The El Paso-Juarez Airshed, Arjun Aryal

Open Access Theses & Dissertations

The study of Solar Irradiance and Aerosol Optical Depth (AOD) plays an important role in understanding the regional and global climate distribution, and is also important in air pollution studies. In this work an MFRSR (Multi-Filter Rotating Shadowband Radiometer) and a Portable Microtop Sunphotometer were used to measure irradiances and to obtain optical depth values for the El Paso-Juarez Airshed. The Langley method applied on the MFRSR irradiance data was used to calculate the AOD values. The spatial distribution of AOD for this region was obtained using a Microtop Sunphotometer. The graphs were generated using GIS Shapefiles. In addition, the …

Spaceborne Synthetic Aperture Radar Survey Of Subsidence In Hampton Roads, Virginia (Usa), D.P.S. Bekaert, B. D. Hamlington, B. Buzzanga, C. E. Jones

CCPO Publications

Over the past century, the Hampton Roads area of the Chesapeake Bay region has experienced one of the highest rates of relative sea level rise on the Atlantic coast of the United States. This rate of relative sea level rise results from a combination of land subsidence, which has long been known to be present in the region, and rising seas associated with global warming on long timescales and exacerbated by shifts in ocean dynamics on shorter timescales. An understanding of the current-day magnitude of each component is needed to create accurate projections of future relative sea level rise upon …

A Climatological And Multiscale Analysis Of Cold Air Outbreaks In The Northeast United States, Zachary Baker Murphy

Legacy Theses & Dissertations (2009 - 2024)

The results of a climatological and multiscale analysis of cold air outbreaks (CAOs) that impacted the Northeast U.S. during 1948–2015 are presented. This climatological and multiscale analysis was based on daily minimum temperature data extracted from the National Centers for Environmental Information (NCEI) Global Historical Climatology Network-Daily dataset for 53 stations that were distributed throughout nine climate regions defined by the NCEI. A CAO is diagnosed whenever two or more stations within an NCEI climate region experience three or more consecutive days where the daily minimum temperatures at a station fall below the 31-day centered moving average of the fifth …