A5069206751- Atmospheric chemistry and aerosols
- Atmospheric Ozone and Climate
- Atmospheric and Environmental Gas Dynamics
- Atmospheric aerosols and clouds
- Theatre and Performance Studies
- Lightning and Electromagnetic Phenomena
- Fire effects on ecosystems
- Meteorological Phenomena and Simulations
- Air Quality and Health Impacts
- Air Quality Monitoring and Forecasting
- Shakespeare, Adaptation, and Literary Criticism
- Theater, Performance, and Music History
- Ionosphere and magnetosphere dynamics
- Vehicle emissions and performance
- Climate variability and models
- Wind and Air Flow Studies
- Plant responses to elevated CO2
- Musicology and Musical Analysis
- Tropical and Extratropical Cyclones Research
- Geophysics and Gravity Measurements
- Historical Art and Culture Studies
- Earthquake Detection and Analysis
- Combustion and Detonation Processes
- Creative Drama in Education
- Impact of Light on Environment and Health
University of Maryland, College Park
2015-2024
Langley Research Center
1990-2023
NOAA Oceanic and Atmospheric Research
2023
Goddard Space Flight Center
2011-2020
Spelman College
2019
National Aeronautics and Space Administration
2016-2019
Earth System Science Interdisciplinary Center
1995-2012
California Institute of Technology
2007
University of New Hampshire
2007
Park University
2000
Acid deposition and photochemical smog are urban air pollution problems, they remain localized as long the sulfur, nitrogen, hydrocarbon pollutants confined to lower troposphere (below about 1-kilometer altitude) where short-lived. If, however, contaminants rapidly transported upper troposphere, then their atmospheric residence times grow range of influence expands dramatically. Although this vertical transport ameliorates some effects acid rain by diluting acids, it exacerbates global...
We have constructed profiles of lightning NO χ mass distribution for use in specifying the effective source global and regional chemical transport models. The been estimated midlatitude continental, tropical marine regimes based on computed individual storms each regime. In order to construct these we developed a parameterization occurrence, type, flash placement, production cloud‐scale tracer model using variables two‐dimensional Goddard Cumulus Ensemble (GCE) model. Wind fields from GCE...
Abstract. This overview paper highlights the successes of Ozone Monitoring Instrument (OMI) on board Aura satellite spanning a period nearly 14 years. Data from OMI has been used in wide range applications and research resulting many new findings. Due to its unprecedented spatial resolution, combination with daily global coverage, plays unique role measuring trace gases important for ozone layer, air quality, climate change. With operational very fast delivery (VFD; direct readout) near...
Abstract Nitrogen oxides (NO x = NO + 2 ) are produced during combustion processes and, thus may serve as a proxy for fossil fuel‐based energy usage and coemitted greenhouse gases other pollutants. We use high‐resolution nitrogen dioxide data from the Ozone Monitoring Instrument (OMI) to analyze changes in urban levels around world 2005 2014, finding complex heterogeneity changes. discuss several potential factors that seem determine these First, environmental regulations resulted large...
Abstract. We describe a new algorithm for the retrieval of nitrogen dioxide (NO2) vertical columns from nadir-viewing satellite instruments. This (SP2) is basis Version 2.1 OMI Ozone Monitoring Instrument (OMI) NO2 Standard Product and features novel method separating stratospheric tropospheric columns. The approach estimates directly data without using chemical transport models or assuming any global zonal wave pattern. Tropospheric are retrieved air mass factors derived high-resolution...
A three‐dimensional (3‐D) cloud‐scale chemical transport model that includes a parameterized source of lightning NO x on the basis observed flash rates has been used to simulate six midlatitude and subtropical thunderstorms during four field projects. Production per intracloud ( P IC ) cloud‐to‐ground CG is estimated by assuming various values for each storm determining which production scenario yields mixing ratios compare most favorably with in‐cloud aircraft observations. We obtain mean...
Emissions of nitrogen oxides (NOx) and, subsequently, atmospheric levels dioxide (NO2) have decreased over the U.S. due to a combination environmental policies and technological change. Consequently, NO2 by 30–40% in last decade. We quantify trends (2005–2013) using surface measurements from Environmental Protection Agency (EPA) Air Quality System (AQS) an improved tropospheric vertical column density (VCD) data product Ozone Monitoring Instrument (OMI) on Aura satellite. demonstrate that...
Abstract The Deep Convective Clouds and Chemistry (DC3) field experiment produced an exceptional dataset on thunderstorms, including their dynamical, physical, electrical structures impact the chemical composition of troposphere. gathered detailed information inflow outflow regions midlatitude thunderstorms in northeast Colorado, west Texas to central Oklahoma, northern Alabama. A unique aspect DC3 strategy was locate sample convective a day after active convection order measure...
Abstract. We assess the standard operational nitrogen dioxide (NO2) data product (OMNO2, version 2.1) retrieved from Ozone Monitoring Instrument (OMI) onboard NASA's Aura satellite using a combination of aircraft and surface in~situ measurements as well ground-based column at several locations bottom-up NOx emission inventory over continental US. Despite considerable sampling differences, NO2 vertical densities OMI are modestly correlated (r = 0.3–0.8) with in situ tropospheric aircraft,...
Satellite data of atmospheric pollutants are becoming more widely used in the decision-making and environmental management activities public, private sector non-profit organizations. They employed for estimating emissions, tracking pollutant plumes, supporting air quality forecasting activities, providing evidence "exceptional event" declarations, monitoring regional long-term trends, evaluating model output. However, many managers not taking full advantage these applications nor has...
A series of large mesoscale convective systems that occurred during the Brazilian phase GTE/TRACE (Transport and Atmospheric Chemistry near Equator‐Atlantic) provided an opportunity to observe deep transport trace gases from biomass burning. This paper reports a detailed analysis flight 6, on September 27, 1992, which sampled cloud‐ biomass‐burning‐perturbed regions north Brasilia. High‐frequency sampling cloud outflow at 9–12 km NASA DC‐8 showed enhancement CO mixing ratios typically factor...
The seasonal tropospheric ozone maximum in the tropical South Atlantic, first recognized from satellite observations [ Fishman et al. , 1986, 1991], gave rise to IGAC/STARE/SAFARI 1992/TRACE A campaigns (International Global Atmospheric Chemistry/South Tropical Atlantic Regional Experiment/Southern African Research Initiative/Transport and Chemistry Near Equator‐Atlantic) September October 1992. Along with a new TOMS‐based method for deriving column ozone, we used TRACE A/SAFARI 1992 data...
A 2D time-dependent and nonhydrostatic numerical cloud model is presently used to estimate the heating, moisture, water budgets in convective stratiform regions for both a tropical midlatitude squall line. The encompasses parameterized, three-class ice phase microphysical scheme longwave radiative transfer process. It noted that region plays an important role generation of rainfall cases. While midlevel minimum moisture profile case due vertical eddy transport region, contribution heating...
Four global scale and three regional chemical transport models are intercompared evaluated during NASA's Transport Chemical Evolution over the Pacific (TRACE‐P) experiment. Model simulated measured CO statistically analyzed along aircraft flight tracks. Results for combination of 11 flights show an overall negative bias in CO. Biases most pronounced large events. Statistical agreements vary greatly among individual flights. Those with greatest range values tend to be worst simulated....
[1] Lightning activity over the West Pacific Ocean east of Philippines is usually much less frequent than nearby maritime continents. However, in 2005 Imaging Sensor (LIS) aboard TRMM satellite observed anomalously high lightning that area. In same year Moderate resolution Spectroradiometer (MODIS) measured aerosol loading. The loading was traced to volcanic activity, and not any factor linked meteorology, disentangling usual convolution between aerosols meteorology. We show general tightly...
A three‐dimensional cloud‐scale chemical transport model has been used to simulate trace gas transport, lightning NO production, and photochemical ozone production in the 12 July 1996 storm observed during Stratosphere‐Troposphere Experiment: Radiation, Aerosols Ozone (STERAO‐A) field experiment. The is driven by meteorological fields from a nonhydrostatic cloud‐resolving (see Stenchikov et al., 2005). An assumption that both cloud‐to‐ground intracloud flashes produce 460 moles NO/flash on...
Abstract Urban heat island (UHI) effects can strengthen waves and air pollution episodes. In this study, the dampening impact of urban trees on UHI during an extreme wave in Washington, D.C., Baltimore, Maryland, metropolitan area is examined by incorporating trees, soil, grass into coupled Weather Research Forecasting model canopy (WRF-UCM). By parameterizing these natural surfaces alongside roadways buildings, modified WRF-UCM used to investigate how dampen UHI. The was run with 50% tree...
At a site near Boulder, Colorado, simultaneous atmospheric measurements were made of NO, NO x , and y in field intercomparison instruments involving two currently employed techniques measurement. Both depended upon the reduction species to with detection by chemiluminescence, but different catalysts for reduction: (1) gold catalyst (with addition 0.3% CO) at 300°C, or (2) molybdenum 400°C. The systems involved photolysis 2 solid ferrous sulfate. Several times during response calibrated...
Photochemical modeling and analysis of field data have been used to evaluate the effects convective clouds on tropospheric trace gas chemistry. Observations were made during a 1985 campaign over rural south‐central United States. Meteorological measurements CO, NO, NO y , O 3 hydrocarbons collected in air surrounding inside immediately following cloud convection. A one‐dimensional photochemical model has calculate production potential before after redistribution precursor gases. Four...
We show that Aura Ozone Monitoring Instrument (OMI) nitrogen dioxide (NO2) tropospheric column data may be used to assess changes of the emissions oxides (NOx) from power plants in United States, though careful interpretation is necessary. There a clear response for OMI NO2 NOx emission reductions associated with implementation mandated control devices (ECDs) over record (2005–2011). This scalar all intents and purposes, whether reduction rapid or incremental several years. However, it...
For the August‐September 2008 Olympic and Paralympic Games held in Beijing, China, strict controls on pollutant emissions motor vehicle traffic were imposed Beijing neighboring provinces to South improve air quality around city. Satellite measurements over between July September showed 43% reductions of tropospheric column nitrogen dioxide, compared past three years. When south are included our analyses, satellite show boundary layer sulfur dioxide 13% carbon monoxide 12% at 700 hPa. Thus,...
The Geostationary Coastal and Air Pollution Events (GEO-CAPE) mission was recommended by the National Research Council's (NRC's) Earth Science Decadal Survey to measure tropospheric trace gases aerosols coastal ocean phytoplankton, water quality, biogeochemistry from geostationary orbit, providing continuous observations within field of view. To fulfill mandate address challenge put forth NRC, two GEO-CAPE Working Groups (SWGs), representing atmospheric composition color disciplines, have...
National emission inventories (NEIs) take years to assemble, but they can become outdated quickly, especially for time-sensitive applications such as air quality forecasting. This study compares multi-year NOx trends derived from satellite and ground observations uses these data evaluate the updates of by US Air Quality Forecast Capability (NAQFC) next-day ozone prediction during 2008 Global Economic Recession. Over eight large cities examined here, both Ozone Monitoring Instrument (OMI)...