A5009914339- Atmospheric chemistry and aerosols
- Atmospheric and Environmental Gas Dynamics
- Air Quality and Health Impacts
- Atmospheric Ozone and Climate
- Climate Change and Health Impacts
- COVID-19 impact on air quality
- Air Quality Monitoring and Forecasting
- Industrial Gas Emission Control
- Environmental Policies and Emissions
- Peatlands and Wetlands Ecology
- Vehicle emissions and performance
- Soil and Water Nutrient Dynamics
- Mercury impact and mitigation studies
- Spectroscopy and Laser Applications
- Ocean Acidification Effects and Responses
- Laser-induced spectroscopy and plasma
- Medical Image Segmentation Techniques
- Catalytic Processes in Materials Science
- Climate Change Policy and Economics
- Image Processing Techniques and Applications
- Geochemistry and Geochronology of Asian Mineral Deposits
- Image and Signal Denoising Methods
- Marine and coastal ecosystems
- Fire effects on ecosystems
- Environmental Monitoring and Data Management
University of Colorado Boulder
2019-2024
University of York
2023
University of Colorado System
2020-2022
Jet Propulsion Laboratory
2021
California Air Resources Board
2021
Peking University
2018-2019
Abstract This study compares recent CO, NO x , NMVOC, SO 2 BC, and OC anthropogenic emissions from several state‐of‐the‐art top‐down estimates to global regional bottom‐up inventories projections five Shared Socioeconomic Pathways (SSPs) in regions. Results show that derived studies exhibit similar uncertainty as some regions for certain species even less the case of Chinese CO emissions. In general, largest discrepancies are found outside such United States, Europe, Japan where most...
The COVID-19 global pandemic and associated government lockdowns dramatically altered human activity, providing a window into how changes in individual behavior, enacted en masse, impact atmospheric composition. resulting reductions anthropogenic activity represent an unprecedented event that yields glimpse future where emissions to the atmosphere are reduced. Furthermore, abrupt reduction during lockdown periods led clearly observable composition, which provide direct insight feedbacks...
Abstract We use 2005–2016 observations of formaldehyde (HCHO) columns over China from the OMI, GOME‐2, and SCIAMACHY satellite instruments to evaluate long‐term trends in emission inventories volatile organic compounds (VOCs) that affect air quality. The show large increases North Plain (+1.1 ± 0.5% a −1 relative 2005) Yangtze River Delta region (+1.5 0.4% 2005), consistent with trend anthropogenic VOC emissions Multi‐resolution Emission Inventory for (MEIC). Unlike other pollutants, have...
Effective mitigation of surface ozone pollution entails detailed knowledge the contributing precursors' sources. We use GEOS-Chem adjoint model to analyze precursors in Beijing–Tianjin–Hebei area (BTH) China on days different severities June 2019. find that BTH heavily polluted is sensitive local emissions, as well emitted from provinces south (Shandong, Henan, and Jiangsu, collectively SHJ area). Heavy can be mitigated effectively by reducing NOx (from industrial processes transportation),...
Abstract. We used the GEOS-Chem model and its adjoint to quantify Chinese non-methane volatile organic compound (NMVOC) emissions for year 2007, using tropospheric column concentrations of formaldehyde glyoxal observed by Global Ozone Monitoring Experiment 2A (GOME-2A) instrument Instrument (OMI) as quantitative constraints. conducted a series inversion experiments different combinations satellite observations explore their impacts on top-down emission estimates. Our estimates annual total...
Spatiotemporal uncertainty in emissions the US hinders prediction of environmental effects atmospheric . We conducted 4D-Var inversions using CrIS remote-sensing observations and GEOS-Chem to estimate monthly over contiguous at 0.25°× 0.3125° resolution 2014, finding they are 33% higher than prior which likely underestimated most agricultural emissions, especially intense springtime fertilizer livestock sources Central US. However, decreases were found Valley, southern Minnesota, northern...
In situ measurements have suggested vehicle emissions may dominate agricultural sources of NH3 in many cities, which is alarming given the potential for urban to significantly increase human exposure ambient particulate matter. However, confirmation prevalence throughout a city has been challenging because mixing with sources, and latter are thus routinely assumed dominate. Here we report based on TROPOMI NO2 CrIS (0.152 kg s–1) that consistent model-based estimate (0.178 show COVID-19...
Abstract. We apply airborne measurements across three seasons (summer, winter and spring 2017–2018) in a multi-inversion framework to quantify methane emissions from the US Corn Belt Upper Midwest, key agricultural wetland source region. Combing our seasonal results with prior fall values we find that wetlands are largest regional (32 %, 20 [16–23] Gg/d), while livestock (enteric/manure; 25 15 [14–17] Gg/d) anthropogenic source. Natural gas/petroleum, waste/landfills, coal mines collectively...
We aim to reduce uncertainties in CH2O and other volatile organic carbon (VOC) emissions through assimilation of remote sensing data. first update a three-dimensional (3D) chemical transport model, GEOS-Chem with the KORUSv5 anthropogenic emission inventory inclusion chemistry for aromatics C2H4, leading modest improvements simulation (normalized mean bias (NMB): -0.57 -0.51) O3 (NMB: -0.25 -0.19) compared against DC-8 aircraft measurements during KORUS-AQ; mixing ratio most VOC species are...
Abstract We present a newly developed approach to characterize the sources of fine particulate matter (PM 2.5 )‐related premature deaths in Europe using chemical transport model GEOS‐Chem and its adjoint. The contributions emissions from each individual country, species, sector are quantified mapped out at km scale. In 2015, total PM ‐related death is estimated be 449,813 (257,846–722,138) Europe, 59.0% which were contributed by domestic anthropogenic emissions. nitrogen oxides, ammonia,...
We conduct the first 4D-Var inversion of NH3 accounting for bi-directional flux, using CrIS satellite observations over Europe in 2016. find posterior emissions peak more springtime than prior at continental to national scales, and annually they are generally smaller central Europe, but larger most rest Europe. Annual anthropogenic 25 European Union members (EU25) 25% higher very close (<2% difference) other inventories. Our annual EU25, UK, Netherlands, Switzerland 10%-20% when treating...
Open burning of crop residues is a strong seasonal source air pollutants in many parts China, but the large day-to-day variability associated emissions pose great challenge for quality forecasts. Here we developed back-propagation neural network (BPNN) ensembles to forecast daily fire pixel counts Southern China during month January. The BPNN were trained using assimilated surface meteorological data (including temperature, relative humidity, pressure, and winds) observations from Moderate...
In practical applications, lattice quantizers leverage discrete points to approximate arbitrary in the lattice. An effective quantizer significantly enhances both accuracy and efficiency of these approximations. context high-dimensional quantization, previous work proposed utilizing low-dimensional optimal addressed challenge determining length ratio orthogonal splicing. Notably, it was demonstrated that fixed ratios orthogonality yield suboptimal results when combining lattices. Building on...
Abstract. Organic aerosol (OA), with a large biogenic fraction in the summertime southeast US, adversely impacts air quality and human health. Stringent controls have recently reduced anthropogenic pollutants including sulfate, whose impact on OA remains unclear. Three filter measurement networks provide long-term constraints sensitivity of to changes inorganic species, sulfate ammonia. The 2000–2013 decreases by 1.7 % yr−1–1.9 yr−1 little month-to-month variability, while declines rapidly...
The COVID-19 global pandemic and associated government lockdowns dramatically altered human activity, providing a window into how changes in individual behavior, enacted en masse, impact atmospheric composition. resulting reductions anthropogenic activity represent an unprecedented event that yields glimpse future where emissions to the atmosphere are reduced. While air pollutants greenhouse gases share many common sources, there is sharp difference response of their concentrations due large...
We present a novel source attribution approach that incorporates satellite data into GEOS-Chem adjoint simulations to characterize the species-specific, regional, and sectoral contributions of daily emissions for 3 air pollutants: fine particulate matter (PM2.5), ozone (O3), nitrogen dioxide (NO2). This is implemented Washington, DC, first 2011, identify urban pollution sources, again 2016, examine response changes in anthropogenic emissions. In contributed an estimated 263 (uncertainty:...
The Beijing-Tianjin-Hebei (BTH) region in China has been frequently suffering from severe haze events (observed daily mean surface fine particulate matter PM2.5 concentrations larger than 150 μg m-3) partially caused by certain types of large-scale synoptic patterns. Black carbon (BC), as an important component and a primarily emitted species, is good tracer for investigating sources formation mechanisms leading to pollutions. We apply GEOS-Chem model its adjoint quantify the source...
Abstract. We used the GEOS-Chem model and its adjoint to quantify Chinese non-methane volatile organic compound (NMVOC) emissions for year 2007, using vertical column concentrations of formaldehyde glyoxal observed by Global Ozone Monitoring Experiment-2A (GOME-2A) instrument Instrument (OMI) as constraints. conducted a series inversion experiments different combinations satellite observations explore impacts on top-down emission estimates due retrievals. Our annual total NMVOC was 23.4 35.4...
Earth and Space Science Open Archive This preprint has been submitted to is under consideration at Earth's Future. ESSOAr a venue for early communication or feedback before peer review. Data may be preliminary.Learn more about preprints preprintOpen AccessYou are viewing the latest version by default [v1]Analysis of recent anthropogenic surface emissions from bottom-up inventories top-down estimates: future emission scenarios valid past?Authors Nellie Elguindi iD Claire Granier Trissevgeni...
The COVID-19 global pandemic and associated government lockdowns dramatically altered human activity, providing a window into how changes in individual behavior, enacted en masse, impact atmospheric composition. resulting reductions anthropogenic activity represent an unprecedented event that yields glimpse both the past future where emissions to atmosphere are reduced. While air pollutants greenhouse gases share many common sources, there is sharp difference response of their concentrations...
Earth and Space Science Open Archive This preprint has been submitted to is under consideration at Journal of Geophysical Research - Atmospheres. ESSOAr a venue for early communication or feedback before peer review. Data may be preliminary.Learn more about preprints preprintOpen AccessYou are viewing the latest version by default [v1]4D-Var inversion European NH3 emissions using CrIS measurements GEOS-Chem adjoint with bi-directional uni-directional flux schemesAuthorsHansenCaoiDDaven...
The COVID-19 global pandemic and associated government lockdowns dramatically altered human activity, providing a window into how changes in individual behavior, enacted en masse, impact atmospheric composition. resulting reductions anthropogenic activity represent an unprecedented event that yields glimpse future where emissions to the atmosphere are reduced. While air pollutants greenhouse gases share many common sources, there is sharp difference response of their concentrations due large...
Abstract. Organic aerosol (OA), with a large biogenic fraction in summertime southeast US, adversely impacts on air quality and human health. Stringent controls have recently reduced anthropogenic pollutants including sulfate, whose impact OA remains unclear. Three filter measurement networks provide long-term constraints the sensitivity of to changes inorganic species, sulfate ammonia. The 2000–2013 decreases by 1.7~1.9 %/year little month-to-month variability, while declines rapidly...
Abstract. We apply airborne measurements across three seasons (summer, winter, spring 2017–2018) in a multi-inversion framework to quantify methane emissions from the US Corn Belt and Upper Midwest, key agricultural wetland source region. Combing our seasonal results with prior fall values we find that wetlands are largest regional (32 %, 20 [16–23] Gg/d), while livestock (enteric/manure; 25 15 [14–17] Gg/d) anthropogenic source. Natural gas/petroleum, waste/landfills, coal mines...