A5001343482- Atmospheric and Environmental Gas Dynamics
- Atmospheric Ozone and Climate
- Atmospheric chemistry and aerosols
- Climate variability and models
- Meteorological Phenomena and Simulations
- Geochemistry and Geologic Mapping
- Geophysics and Gravity Measurements
- Air Quality Monitoring and Forecasting
- Ionosphere and magnetosphere dynamics
- Hydrocarbon exploration and reservoir analysis
- CO2 Sequestration and Geologic Interactions
- Spectroscopy and Laser Applications
- Climate Change and Health Impacts
- COVID-19 impact on air quality
- Calibration and Measurement Techniques
- Spaceflight effects on biology
- Solar and Space Plasma Dynamics
- Cryospheric studies and observations
- Cardiac Arrest and Resuscitation
- Advanced X-ray and CT Imaging
- Ecosystem dynamics and resilience
- Neurosurgical Procedures and Complications
- Trauma and Emergency Care Studies
- Ocean Waves and Remote Sensing
- COVID-19 diagnosis using AI
Goddard Space Flight Center
2014-2024
Morgan State University
2022-2024
Science Systems and Applications (United States)
2024
Universities Space Research Association
2017-2023
Illinois College
2020-2022
National Aeronautics and Space Administration
2021
University of Illinois Urbana-Champaign
2020
Oregon State University
2011-2013
University of Arizona
2011
NASA's Orbiting Carbon Observatory-2 (OCO-2) mission was motivated by the need to diagnose how increasing concentration of atmospheric carbon dioxide (CO
We show that transport differences between two commonly used global chemical models, GEOS-Chem and TM5, lead to systematic space-time in modeled distributions of carbon dioxide sulfur hexafluoride. The distribution suggests inconsistencies the simulated by most likely due representation vertical motion. further demonstrate these result surface CO
Abstract. The Orbiting Carbon Observatory 2 (OCO-2) satellite has been providing information to estimate carbon dioxide (CO2) fluxes at global and regional scales since 2014 through the combination of CO2 retrievals with top–down atmospheric inversion methods. Column average dry-air mole fraction have constantly improved. A bias correction applied in OCO-2 version 9 compared previous 7r improving data accuracy coverage. We study an ensemble 10 inversions all characterized by different...
Abstract. The version 10 (v10) Atmospheric Carbon Observations from Space (ACOS) Level 2 full-physics (L2FP) retrieval algorithm has been applied to multiyear records of observations NASA's Orbiting Observatory and 3 sensors (OCO-2 OCO-3, respectively) provide estimates the carbon dioxide (CO2) column-averaged dry-air mole fraction (XCO2). In this study, a number improvements ACOS v10 L2FP are described. post-processing quality filtering bias correction XCO2 against multiple truth proxies...
Abstract A rare disturbance of the stratospheric Antarctic polar vortex in September 2019 led to a significantly higher than usual total ozone column. We use assimilation ozone, HCl, and N 2 O data from Microwave Limb Sounder with Global Earth Observing System (GEOS) Constituent Data Assimilation driven by reanalysis meteorology study evolution ozone. find that maximum hole area was near 10 × 6 km , as little 20% 2018 mid‐September. However, magnitude vortex‐averaged chemical depletion not...
Activity reductions in early 2020 due to the coronavirus disease 2019 pandemic led unprecedented decreases carbon dioxide (CO2) emissions. Despite their record size, resulting atmospheric signals are smaller than and obscured by climate variability transport biospheric fluxes, notably that related 2019–2020 Indian Ocean Dipole. Monitoring CO2 anomalies distinguishing human climatic causes thus remain a new frontier Earth system science. We show impact of short-term regional changes fossil...
Abstract The Atmospheric Carbon and Transport (ACT)-America NASA Earth Venture Suborbital Mission set out to improve regional atmospheric greenhouse gas (GHG) inversions by exploring the intersection of strong GHG fluxes vigorous transport that occurs within midlatitudes. Two research aircraft instrumented with remote in situ sensors measure mole fractions, associated trace gases, state variables collected 1,140.7 flight hours data, distributed across 305 individual sorties, coordinated 121...
Abstract. Inverse model intercomparison projects (MIPs) provide a chance to assess the uncertainties in inversion estimates arising from various sources. However, accurately quantifying ensemble CO2 flux errors remains challenging and often relies on spread. This study proposes method for regional net surface–atmosphere models taken Orbiting Carbon Observatory-2 (OCO-2) v10 MIP by using independent airborne measurements period 2015–2017. We first calculate root mean square error (RMSE)...
The hydroxyl radical (OH) is the dominant tropospheric oxidant and therefore responsible for setting lifetime of several key atmospheric constituents, including methane. Despite its importance, however, there are no global in situ or remote sensing networks that directly observe this species. Methyl chloroform (MCF) inversions, often used to infer interannual variability trends OH, only provide information at hemispheric scales have become less reliable as MCF concentrations decline. This...
We present an evaluation of airborne Intensity-Modulated Continuous-Wave (IM-CW) lidar measurements atmospheric column CO2 mole fractions during the ACT-America project. This system transmits online and offline wavelengths simultaneously on 1.57111-um absorption line, with each modulated wavelength using orthogonal swept frequency waveforms. After spectral characteristics this were calibrated through short-path measurements, we used HITRAN spectroscopic database to derive average-column...
Abstract With nearly 1 million observations of column‐mean carbon dioxide concentration (X ) per day, the Orbiting Carbon Observatory 2 (OCO‐2) presents exciting possibilities for monitoring global cycle, including detection subcontinental column CO variations. While OCO‐2 data set has been shown to achieve target precision and accuracy on a single‐sounding level, validation X spatial gradients scales remains challenging. In this work, we investigate use an integrated path differential...
Abstract. The ability to monitor and understand natural anthropogenic variability in atmospheric carbon dioxide (CO2) is a growing need of many stakeholders across the world. Systems that assimilate satellite observations, given their short latency dense spatial coverage, into high-resolution global models are valuable, if not essential, tools for addressing this need. A notable drawback modern assimilation systems long vital input datasets; example, inventories, situ measurements,...
Abstract. Accurate estimates of carbon–climate feedbacks require an independent means for evaluating surface flux models at regional scales. The altitude-integrated enhancement (AIE) derived from the Arctic Carbon Atmospheric Profiles (Arctic-CAP) project demonstrates utility this bulk quantity model evaluation. This leverages background mole fraction values middle free troposphere, is agnostic to uncertainties in boundary layer height, and can be fractions vertical gradients. To demonstrate...
Abstract The MERRA‐2 Stratospheric Composition Reanalysis of Aura Microwave Limb Sounder (M2‐SCREAM) is a new reanalysis stratospheric ozone, water vapor, hydrogen chloride (HCl), nitric acid (HNO 3 ) and nitrous oxide (N 2 O) between 2004 the present (with latency several months). assimilated fields are provided at 50‐km horizontal resolution three‐hourly frequency. M2‐SCREAM assimilates version 4.2 (MLS) profiles five constituents alongside total ozone column from Ozone Monitoring...
Abstract. The tropospheric hydroxyl (TOH) radical is a key player in regulating oxidation of various compounds Earth's atmosphere. Despite its pivotal role, the spatiotemporal distributions OH are poorly constrained. Past modeling studies suggest that main drivers OH, including NO2, ozone (TO3), and H2O(v), have increased TOH globally. However, these findings often offer global average may not include more recent changes diverse emitted on scales. Here, we aim to deepen our understanding...
[1] We use the vortex force formalism to analyze effect of rip currents on their own wave forcing. The allows us decompose forcing into nonconservative flux momentum due breaking and conservative force. Following Yu Slinn (2003), we consider initially generated by alongshore variation a perturbation barred bottom topography. This is reduced in magnitude two current effects waves: ray bending energy currents. compute change caused these this show that relative scales with square ratio length...
Abstract Compatibility of the stratospheric ozone profile data from Ozone Mapping and Profiler Suite Limb (OMPS‐LP) Microwave Sounder (MLS) is assessed in context a continuity requirement for future reanalyses. A methodology assimilation OMPS‐LP into Goddard Earth Observing System system with chemistry module developed. It demonstrated that simple homogenization technique significantly reduces bias between MLS analyses. With applied, mean difference two analyses within 3% standard deviation...
Abstract. The tropospheric hydroxyl radical (TOH) is a key player in regulating oxidation of various compounds Earth’s atmosphere. Despite its pivotal role, the spatiotemporal distributions OH are poorly constrained. Past modeling studies suggest that main drivers OH, including NO2, ozone (TO3), and H2O(v), have increased TOH globally. However, these findings often offer global average may not include more recent changes diverse emitted on scales. Here, we aim to deepen our understanding...
Abstract The ability of current global models to simulate the transport CO 2 by mid‐latitude, synoptic‐scale weather systems (i.e., weather) is important for inverse estimates regional and carbon budgets but remains unclear without comparisons targeted measurements. Here, we evaluate ten that participated in Orbiting Carbon Observatory‐2 model intercomparison project (OCO‐2 MIP version 9) with intensive aircraft measurements collected from Atmospheric Transport (ACT)‐America mission. We...
Abstract. This paper presents a particle method designed for high-dimensional state estimation. Instead of weighing random forecasts by their distance to given observations, the samples an ensemble particles around optimal solution based on observations (i.e., it is implicit). It differs from other implicit methods because includes at previous assimilation time as part lag-1 smoother). accomplished through use mixture model background distribution state. In high-dimensional, linear, Gaussian...
Abstract. The hydroxyl radical (OH) plays a central role in tropospheric chemistry, as well influencing the lifetimes of some greenhouse gases. Because limitations our ability to observe OH, we have historically relied on indirect methods constrain its concentrations, trends, and variations but only annual global or semi-hemispheric averages. Recent demonstrated feasibility indirectly constraining OH finer spatio-temporal scales using satellite observations proxies for photochemical drivers...
Abstract. Land carbon fluxes, e.g., gross primary production (GPP) and net biome (NBP), are controlled in part by the responses of terrestrial ecosystems to atmospheric conditions near Earth's surface. The Coupled Model Intercomparison Project Phase 6 (CMIP6) has recently proposed increased spatial temporal resolutions for surface CO2 concentrations used calculate GPP, yet a comprehensive evaluation consequences this resolution cycle dynamics is missing. Here, using global offline...
Abstract Tropical lands play an important role in the global carbon cycle yet their contribution remains uncertain owing to sparse observations. Satellite observations of atmospheric dioxide (CO 2 ) have greatly increased spatial coverage over tropical regions, providing potential for improved estimates terrestrial fluxes. Despite this advancement, spread among satellite‐based and in‐situ CO flux inversions northern Africa (NTA), spanning 0–24°N, large. Satellite‐based annual source 0.8–1.45...