A5019305560- Atmospheric and Environmental Gas Dynamics
- Atmospheric Ozone and Climate
- Atmospheric chemistry and aerosols
- Hydrocarbon exploration and reservoir analysis
- Meteorological Phenomena and Simulations
- Climate variability and models
- Methane Hydrates and Related Phenomena
- CO2 Sequestration and Geologic Interactions
- Carbon Dioxide Capture Technologies
- Geochemistry and Geologic Mapping
- Climate Change Policy and Economics
- Air Quality Monitoring and Forecasting
- Environmental Impact and Sustainability
- Vehicle emissions and performance
- Reservoir Engineering and Simulation Methods
- Spectroscopy and Laser Applications
- Geophysics and Gravity Measurements
- Oceanographic and Atmospheric Processes
- Geological Studies and Exploration
- Air Quality and Health Impacts
- Oil, Gas, and Environmental Issues
- Wind and Air Flow Studies
- Plant Water Relations and Carbon Dynamics
- Air Traffic Management and Optimization
- Ocean Acidification Effects and Responses
Colorado State University
2014-2025
Cooperative Institute for Research in Environmental Sciences
2013-2025
National Oceanic and Atmospheric Administration
2024
Ames Research Center
2021
Jet Propulsion Laboratory
2021
Institute for Sports Medicine
1992
Abstract. The Orbiting Carbon Observatory-2 has been on orbit since 2014, and its global coverage holds the potential to reveal new information about carbon cycle through use of top-down atmospheric inversion methods combined with column average CO2 retrievals. We employ a large ensemble inversions utilizing different transport models, data assimilation techniques, prior flux distributions in order quantify satellite-informed fluxes from OCO-2 Version 7r land observations their uncertainties...
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. Accurate accounting of emissions and removals CO2 is critical for the planning verification emission reduction targets in support Paris Agreement. Here, we present a pilot dataset country-specific net carbon exchange (NCE; fossil plus terrestrial ecosystem fluxes) stock changes aimed at informing countries' budgets. These estimates are based on “top-down” NCE outputs from v10 Orbiting Carbon Observatory (OCO-2) modeling intercomparison project (MIP), wherein an ensemble inverse...
Abstract. We performed an atmospheric inversion of the CO2 fluxes over Iowa and surrounding states, from June to December 2007, at 20 km resolution weekly timescale. Eight concentration towers were used constrain carbon balance in a 1000×1000 km2 domain this agricultural region US upper midwest. The concentrations boundaries derived CarbonTracker adjusted match direct observations aircraft profiles around domain. regional ends up with sink 183 Tg C±35 C area for period June–December, 2007....
Abstract. Resolving the discrepancies between NEE estimates based upon (1) ground studies and (2) atmospheric inversion results, demands increasingly sophisticated techniques. In this paper we present a high-resolution regional meteorology model (RAMS) an underlying biosphere (SiB3) model, both running on identical 40 km grid over most of North America. Current operational systems like CarbonTracker as well many previous global inversions including Transcom suite have utilized regions formed...
An intensive regional research campaign was conducted by the North American Carbon Program (NACP) in 2007 to study carbon cycle of highly productive agricultural regions Midwestern United States. Forty-five different associated projects were across five US agencies over course nearly a decade involving hundreds researchers. One primary objectives investigate ability atmospheric inversion techniques use calibrated CO2 mixing ratio data estimate flux major croplands States comparing results an...
Abstract Methods for determining patterns of migratory connectivity in animal ecology have historically been limited due to logistical challenges. Recent progress studying bird has made using genetic and stable‐isotope markers assign individuals their breeding grounds. Here, we present a novel B ayesian approach jointly leverage isotopic test its utility on two passerine species. Our represents principled model‐based combination isotope data from samples collected the grounds is able achieve...
We evaluate the capability of an ensemble based data assimilation approach, referred to as Maximum Likelihood Ensemble Filter (MLEF), estimate biases in CO 2 photosynthesis and respiration fluxes. employ off‐line Lagrangian Particle Dispersion Model (LPDM), which is driven by carbon fluxes, obtained from Simple Biosphere ‐ Regional Atmospheric Modeling System (SiB‐RAMS). The SiB‐RAMS fluxes are assumed have errors form multiplicative biases. Our goal reduce these also assign reliable...
Recent instrumental deployments of regional observation networks atmospheric CO2 mixing ratios have been used to constrain carbon sources and sinks using inversion methodologies. In this study, we performed sensitivity experiments sites from the Mid Continent Intensive experiment evaluate required spatial density locations concentration towers based on flux corrections error reduction analysis. addition, investigated impact prior structures with different correlation lengths biome...
Abstract Regional estimates of biogenic carbon fluxes over North America from both atmospheric inversions (“top‐down” approach) and terrestrial biosphere models (“bottom‐up”) remain highly uncertain. We merge these approaches with an ensemble‐based, regional modeling system able to diagnose quantify the causes uncertainties in top‐down sink America. Our ensemble approach quantifies partitions uncertainty stemming transport, biosphere, large‐scale CO 2 boundary inflow (boundary conditions)....
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. There is a growing interest in estimating urban CO2 emission from spaceborne imagery of the column-average dry-air mole fraction (XCO2). Emission estimation methods have been widely tested and applied to actual or synthetic images. However, there still lack objective criteria for selecting images that are worth processing. This study analyzes performances an automated method emissions as function targeted cities atmospheric conditions. It uses data experiments with truth 9920...
Human conversion of natural ecosystems to croplands modifies not only the exchange water and energy between surface atmosphere, but also carbon fluxes. To investigate impacts crops on fluxes resulting atmospheric CO2 concentrations in mid-continent region United States, we coupled a crop-specific phenology physiology scheme for corn, soybean wheat ecosystem–atmosphere model SiB3–RAMS. Using SiBcrop–RAMS improved at local scale had regional impacts, decreasing spring uptake increasing summer...
Abstract. Carbon fixed by agricultural crops in the US creates regional CO2 sinks where it is harvested and sources released back to atmosphere. The quantity location of these fluxes differ depending on annual supply demand crop commodities. Data harvest biomass, storage, import export, use biomass for food, feed, fiber, fuel were compiled estimate an carbon budget 2000 2008. With respect Farm Resource Regions, net associated with consumption commodities occurred Eastern Uplands, Southern...
Verifying national greenhouse gas (GHG) emissions inventories is a critical step to ensure that reported data the United Nations Framework Convention on Climate Change (UNFCCC) are accurate and representative of country's contribution GHG concentrations in atmosphere. Furthermore, verifying biogenic fluxes provides check estimated associated with managing lands for carbon sequestration other activities, which often have large uncertainties. We report here challenges results case study using...
Abstract. The analysis of observed atmospheric trace-gas mole fractions to infer surface sources and sinks chemical species relies heavily on simulated transport. transport models (CTMs) used in flux-inversion are commonly configured reproduce the a general circulation model (GCM) as closely possible. CTMs generally have dual advantages computational efficiency improved tracer conservation compared their parent GCMs, but they usually simplify representations important processes. This is...
This paper investigates the effect of fine‐scale spatial variability in carbon fluxes upon regional flux inversion estimates North America using simulated data from 1 May through 31 August 2004 and a hypothetical sparse network eight towers America. A suite random smooth patterns are created then obscured with “noise” to mimic heterogeneity found nature. Five hundred forty grid‐scale atmospheric inversions run synthetic data. We find that, regardless particular fine scale used (noise), can...
Land carbon sink is a vital component for the achievement of China's ambitious neutrality goal, but its magnitude poorly known. Atmospheric observations and inverse models are valuable tools to constrain land sink. Space-based CO2 measurements from satellites form an emerging data stream application such atmospheric inversions. Here, we reviewed satellite missions that dedicated monitoring , recent progresses on inversion using measurements. We summarized limitations challenges in current...
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 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...
Abstract. The Orbiting Carbon Observatory 2 (OCO-2) satellite has been provided 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 constantly improved. A bias correction applied in OCO-2 version 9 compared previous 7r improving data accuracy coverage. We study an ensemble ten inversions all characterized by different transport...