A5088521482- Atmospheric chemistry and aerosols
- Atmospheric and Environmental Gas Dynamics
- Atmospheric Ozone and Climate
- Air Quality and Health Impacts
- Climate variability and models
- Vehicle emissions and performance
- Atmospheric aerosols and clouds
- Air Quality Monitoring and Forecasting
- Meteorological Phenomena and Simulations
- Geophysics and Gravity Measurements
- Plant responses to elevated CO2
- Land Use and Ecosystem Services
- Maritime Transport Emissions and Efficiency
- Plant Ecology and Soil Science
- Plant Water Relations and Carbon Dynamics
- Aeolian processes and effects
- Remote Sensing and Land Use
- Hydrology and Watershed Management Studies
- Environmental Changes in China
- Fire effects on ecosystems
- Traffic Prediction and Management Techniques
- Catalytic Processes in Materials Science
- Geology and Paleoclimatology Research
- Hydrology and Drought Analysis
- Water Quality Monitoring and Analysis
University of Maryland, College Park
2017-2024
Earth System Science Interdisciplinary Center
2024
Nanjing University of Information Science and Technology
2024
George Mason University
2015-2022
NOAA National Centers for Environmental Prediction
2015-2022
Jet Propulsion Laboratory
2013-2015
NSF National Center for Atmospheric Research
2015
Harbin University of Science and Technology
2015
California Institute of Technology
2014
University of Iowa
2010-2013
Abstract Despite the known biochemical production of a range aromatic compounds by plants and presence benzenoids in floral scents, emissions only few benzenoid have been reported from biosphere to atmosphere. Here, using evidence measurements at aircraft, ecosystem, tree, branch leaf scales, with complementary isotopic labeling experiments, we show that vegetation (leaves, flowers phytoplankton) emits wide variety atmosphere substantial rates. Controlled environment experiments are able...
Abstract. The recent update on the US National Ambient Air Quality Standards (NAAQS) of ground-level ozone (O3) can benefit from a better understanding its source contributions in different regions during years. In Hemispheric Transport Pollution experiment phase 1 (HTAP1), various global models were used to determine O3 source–receptor (SR) relationships among three continents Northern Hemisphere 2001. support HTAP 2 (HTAP2) that studies more years and involves higher-resolution regional...
Abstract In California, emission control strategies have been implemented to reduce air pollutants. Here we estimate the changes in nitrogen oxides (NO x = NO + 2 ) emissions 2005–2010 using a state‐of‐the‐art four‐dimensional variational approach. We separately and jointly assimilate surface concentrations tropospheric columns observed by Ozone Monitoring Instrument (OMI) into regional‐scale Sulfur Transport dEposition Model (STEM) chemical transport model on 12 × km horizontal resolution...
Abstract. Multi-scale tracer and full-chemistry simulations with the STEM atmospheric chemistry model are used to analyze effects of transported background ozone (O3) from eastern Pacific on California air quality during ARCTAS-CARB experiment conducted in June, 2008. Previous work has focused importance long-range transport O3 North America springtime. However this summer is also shown be important. Simulated observed patterns coast inland northern vary based meteorological conditions...
W126 is a cumulative ozone exposure index based on sigmoidally weighted daytime concentrations used to evaluate the impacts of vegetation. We quantify in U.S. absence North American anthropogenic emissions (North background or “NAB”) using three regional global chemical transport models for May–July 2010. All overestimate eastern due persistent bias ozone, while are relatively unbiased California and Intermountain West. Substantial difference magnitude spatial temporal variability estimates...
Abstract. Tropospheric ozone results from in situ chemical formation and stratosphere–troposphere exchange (STE), with the latter being more important middle upper troposphere than lower troposphere. Ozone photochemical is nonlinear oxidation of methane non-methane hydrocarbons (NMHCs) presence nitrogen oxide (NOx=NO+NO2). Previous studies showed that O3 short- long-term trends are nonlinearly controlled by near-surface anthropogenic emissions carbon monoxide (CO), volatile organic compounds...
Abstract. This study describes the application of a regional Earth system model with updated parameterizations for selected land–atmosphere exchange processes and multiplatform, multidisciplinary observations. We estimate reactive nitrogen (Nr = NOy+ NHx) emissions from various sources, surface column dioxide (NO2), total speciated Nr dry wet deposition during 2018–2023 over northeastern mid-Atlantic US where nitrogen-oxide-limited or transitional chemical regimes dominate. The estimated...
Abstract. Over the past few decades, ozone risk assessments for vegetation have been developed based on stomatal O3 flux since this metric is more biologically meaningful than traditional concentration-based approaches. However, uncertainty remains in ability to simulate fluxes accurately. Here, we investigate simulated by six common air pollution deposition models across various land cover types worldwide. The Tropospheric Ozone Assessment Report (TOAR) database, a large collection of...
Abstract. The impacts of transported background (TBG) pollutants on western US ozone (O3) distributions in summer 2008 are studied using the multi-scale Sulfur Transport and dEposition Modeling system. Forward sensitivity simulations show that TBG contributes ~30–35 ppb to surface Monthly mean Daily maximum 8-h Average O3 (MDA8) over Pacific Southwest (US Environmental Protection Agency (EPA) Region 9, including California, Nevada Arizona) Northwest (EPA 10, Washington, Oregon Idaho), ~10–17...
Abstract Western U.S. near‐surface ozone (O 3 ) concentrations are sensitive to transported background O from the eastern Pacific free troposphere, as well anthropogenic and natural emissions. The current 75 ppbv primary standard may be lowered soon, hence accurately estimating source contributions, especially in this region has growing policy‐relevant significance. In study, we improve modeled total , via repartitioning redistributing contributions nonlocal local anthropogenic/wildfires...
Abstract The impact of Southern California (SoCal) anthropogenic emissions on ozone (O 3 ) in the mountain states May 2010 is studied using Sulfur Transport and Deposition Model. We identified two to six major transport events from SoCal different subregions states, with times 0–2 days indicated by trajectories, time‐lag correlations, forward/adjoint sensitivities. Based forward sensitivity analysis, contributions monthly mean daily maximum 8 h average (MDA8) surface O decrease distance...
Abstract. Dust aerosols affect human life, ecosystems, atmospheric chemistry and climate in various aspects. Some studies have revealed intensified dust activity the western US during past decades despite weaker non-US regions. It is important to extend historical records, better understand their temporal changes, use such information improve daily forecasting skill as well projection of future under changing climate. This study develops records Arizona 2005–2013 using multiple observation...
Environmental context. Dust particles produced from wind blown soils are of global significance as these dust not only impact visibility, evident in the recent 2009 Australian storm, but also atmospheric chemistry, climate and biogeochemical cycles. The amount water vapour atmosphere (relative humidity) can play a role processes yet there few studies little quantitative data on water-dust particle interactions. focus this research is quantifying interactions for several sources including...
Abstract This study evaluates the impact of assimilating soil moisture data from National Aeronautics and Space Administration (NASA)'s Soil Moisture Active Passive (SMAP) on short‐term regional weather air quality modeling in East Asia during Korea‐U.S. Air Quality Study (KORUS‐AQ) airborne campaign. SMAP are assimilated into Noah land surface model using an ensemble Kalman filter approach Land Information System framework, which is semicoupled with NASA‐Unified Weather Research Forecasting...
Abstract. Chronic high surface ozone (O3) levels and the increasing sulfur oxides (SOx = SO2+SO4) ambient concentrations over South Coast (SC) other areas of California (CA) are affected by both local emissions long-range transport. In this paper, multi-scale tracer, full-chemistry adjoint simulations using STEM atmospheric chemistry model conducted to assess contribution emission sourcesto SC O3 evaluate impacts transported on budgetduring ARCTAS-CARB experiment period in 2008. Sensitivity...
Abstract. This study evaluates the impact of satellite soil moisture (SM) data assimilation (DA) on regional weather and ozone (O3) modeling over southeastern US during summer. Satellite SM are assimilated into Noah land surface model using an ensemble Kalman filter approach within National Aeronautics Space Administration's Land Information System framework, which is semicoupled with Weather Research Forecasting online Chemistry (WRF-Chem; standard version 3.9.1.1). The DA impacts...
Abstract. Open biomass burning has major impacts globally and regionally on atmospheric composition. Fire emissions include particulate matter, tropospheric ozone precursors, greenhouse gases, as well persistent organic pollutants, mercury other metals. frequency, intensity, duration, location are changing the climate warms, modelling these fires their is becoming more critical to inform adaptation mitigation, land management. Indeed, air pollution from can reverse progress made by emission...
Abstract. Ozone (O3) dry deposition is a major O3 sink. As follow-up study of Huang et al. (2021), we quantify the impact satellite soil moisture (SM) on model representations this process when different dry-deposition parameterizations are implemented, based which implications for interpreting air pollution levels and assessing impacts human ecosystem health provided. The SM data from NASA's Soil Moisture Active Passive mission assimilated into Noah-Multiparameterization (Noah-MP) land...
Abstract While previous studies have demonstrated that the El Niño-Southern Oscillation (ENSO) can impact global climate systems on intraseasonal timescale, how ENSO affects variability of Siberian high (SH) still remains unclear. Based spectral analysis, SH exhibits evident periodicity (ISP) differences, with 25–50 d during Niño winters and 50–90 La Niña winters. The northward propagation Rossby wave from tropics phase transition leads to Madden–Julian oscillation (MJO) dominating...
Abstract Based on a semiempirical diurnal temperature cycle model and aircraft observations taken at different times of the day, daytime land surface (LST) is derived six locations in Greater Houston area least cloudy day during NASA's DISCOVER‐AQ (Deriving Information Surface Conditions from Column Vertically Resolved Observations Relevant to Air Quality) field campaign September 2013. The aircraft‐derived LSTs show ranges (max‐min) 11–25°K varying by location, with daily maxima occurring...
Abstract. Land and atmospheric initial conditions of the Weather Research Forecasting (WRF) model are often interpolated from a different output. We perform case studies during NASA's SEAC4RS DISCOVER-AQ Houston airborne campaigns, demonstrating that using land directly downscaled coarser resolution dataset led to significant positive biases in coupled NASA-Unified WRF (NUWRF, version 7) surface near-surface air temperature planetary boundary layer height (PBLH) around Missouri Ozarks...