A5015215718- Atmospheric and Environmental Gas Dynamics
- Atmospheric chemistry and aerosols
- Atmospheric Ozone and Climate
- Methane Hydrates and Related Phenomena
- Climate variability and models
- Hydrocarbon exploration and reservoir analysis
- Fire effects on ecosystems
- Climate change and permafrost
- Meteorological Phenomena and Simulations
- Spectroscopy and Laser Applications
- Carbon Dioxide Capture Technologies
- Plant Water Relations and Carbon Dynamics
- Cryospheric studies and observations
- Geochemistry and Geologic Mapping
- Geology and Paleoclimatology Research
- CO2 Sequestration and Geologic Interactions
- Air Quality and Health Impacts
- Isotope Analysis in Ecology
- Climate Change Policy and Economics
- Global Energy and Sustainability Research
- Air Quality Monitoring and Forecasting
- Economic and Environmental Valuation
- Environmental Impact and Sustainability
- Vehicle emissions and performance
- Oil, Gas, and Environmental Issues
NOAA Earth System Research Laboratory
2013-2025
National Oceanic and Atmospheric Administration
2016-2025
Massachusetts Eye and Ear Infirmary
2023
University of Oxford
2022
Catholic University of Croatia
2022
Ludwig-Maximilians-Universität München
2022
Cooperative Institute for Research in Environmental Sciences
2010-2020
University of Leeds
2020
University of Colorado Boulder
2009-2018
Institute of Arctic and Alpine Research
1999-2018
We present an estimate of net CO(2) exchange between the terrestrial biosphere and atmosphere across North America for every week in period 2000 through 2005. This is derived from a set 28,000 mole fraction observations global that are fed into state-of-the-art data assimilation system called CarbonTracker. By design, surface fluxes produced CarbonTracker consistent with recent history provide constraints on carbon flux independent national inventories accounting efforts. find American to...
Tropical carbon emissions are largely derived from direct forest clearing processes. Yet, drought-induced fires are, usually, not included in national-level emission inventories. Here we examine Brazilian Amazon drought impacts on fire incidence and associated over the period 2003-2015. We show that despite a 76% decline deforestation rates past 13 years, increased by 36% during 2015 compared to preceding 12 years. The had largest ever ratio of active counts deforestation, with occurring an...
Measurements of atmospheric CH 4 from air samples collected weekly at 46 remote surface sites show that, after a decade near‐zero growth, globally averaged methane increased during 2007 and 2008. During 2007, by 8.3 ± 0.6 ppb. mole fractions over polar northern latitudes the Southern Hemisphere more than other zonally regions. In 2008, 4.4 ppb; largest increase was in tropics, while did not increase. Satellite situ CO observations suggest only minor contribution to biomass burning. The most...
Methane retrievals from the Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY) instrument onboard ENVISAT provide important information on atmospheric CH 4 sources, particularly in tropical regions which are poorly monitored by situ surface observations. Recently, Frankenberg et al. (2008a, 2008b) reported a major revision of SCIAMACHY due to an update spectroscopic parameters water vapor and . Here, we analyze impact this global regional emissions estimates...
Significance Successful regulation of greenhouse gas emissions requires knowledge current methane emission sources. Existing state regulations in California and Massachusetts require ∼15% reductions from levels by 2020. However, government estimates for total US may be biased 50%, individual source sectors are even more uncertain. This study uses atmospheric observations to reduce this level uncertainty. We find agriculture fossil fuel extraction processing (i.e., oil and/or natural gas)...
Abstract From 2007 to 2013, the globally averaged mole fraction of methane in atmosphere increased by 5.7 ± 1.2 ppb yr −1 . Simultaneously, δ 13 C CH4 (a measure C/ 12 isotope ratio methane) has shifted significantly more negative values since 2007. Growth was extreme 2014, at 12.5 0.4 ppb, with a further shift being observed most latitudes. The isotopic evidence presented here suggests that rise dominated significant increases biogenic emissions, particularly tropics, for example, from...
Getting a rise out of agriculture Methane, powerful and important greenhouse gas, has been accumulating nearly uninterruptedly in the atmosphere for past 200 years, with exception mysterious plateau between 1999 2006. Schaefer et al. measured methane's carbon isotopic composition samples collected over 35 years order to constrain cause pause. Lower thermogenic emissions or variations hydroxyldriven methane sink caused plateau. Thermogenic didn't resume subsequent rise. Instead, ongoing is...
The globally‐averaged atmospheric methane abundance determined from an extensive network of surface air sampling sites was constant at ∼1751 ppb 1999 through 2002. Assuming that the lifetime has been constant, this implies during 4‐year period global budget steady state. We also observed a significant decrease in difference between northern and southern polar zonal annual averages CH 4 1991 to 1992. Using 3‐D transport model, we show change is consistent with emissions ∼10 Tg north 50°N...
The multispecies analysis of daily air samples collected at the NOAA Boulder Atmospheric Observatory (BAO) in Weld County northeastern Colorado since 2007 shows highly correlated alkane enhancements caused by a regionally distributed mix sources Denver‐Julesburg Basin. To further characterize emissions methane and non‐methane hydrocarbons (propane, n‐butane, i‐pentane, n‐pentane benzene) around BAO, pilot study involving automobile‐based surveys was carried out during summer 2008. A venting...
Abstract. This synthesis discusses the emissions of carbon dioxide from fossil-fuel combustion and cement production. While much is known about these emissions, there still that unknown details surrounding emissions. explores our knowledge in terms why concern them; how they are calculated; major global efforts on inventorying their global, regional, national totals at different spatial temporal scales; distributed grids (i.e., maps); transported models; uncertainties associated with aspects...
We report a 2000-year Antarctic ice-core record of stable carbon isotope measurements in atmospheric methane (delta13CH4). Large delta13CH4 variations indicate that the budget varied unexpectedly during late preindustrial Holocene (circa 0 to 1700 A.D.). During first thousand years (0 1000 A.D.), was at least 2 per mil enriched compared expected values, and following 700 years, an about depletion occurred. Our modeled source partitioning implies biomass burning emissions were high from A.D....
Abstract. A globally integrated carbon observation and analysis system is needed to improve the fundamental understanding of global cycle, our ability project future changes, verify effectiveness policies aiming reduce greenhouse gas emissions increase sequestration. Building an requires transformational advances from existing sparse, exploratory framework towards a dense, robust, sustained in all components: anthropogenic emissions, atmosphere, ocean, terrestrial biosphere. The paper...
ABSTRACT This paper presents a compilation of atmospheric radiocarbon for the period 1950–2019, derived from CO 2 sampling and tree rings clean-air sites. Following approach taken by Hua et al. (2013), our revised extended consists zonal, hemispheric global ( 14 C) data sets, with monthly sets 5 zones (Northern Hemisphere 1, 2, 3, Southern 3 1–2). Our new includes smooth curves zonal that are more suitable dating applications than previous based on simple averaging. dataset is intended to...
Abstract We present an estimate of net ecosystem exchange (NEE) CO 2 in Europe for the years 2001–2007. It is derived with a data assimilation that uses large set atmospheric mole fraction observations (∼70 000) to guide relatively simple descriptions terrestrial and oceanic exchange, while fossil fuel fire emissions are prescribed. Weekly sources sinks optimized (i.e., flux inversion) 18 ecosystems across which prescribed climate, weather, surface characteristics introduce finer scale...
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...
Abstract Seasonal spatial and temporal gradients for the CO 2 mole fraction over North America are examined by creating a climatology from data collected 2004–2013 NOAA/ESRL Global Greenhouse Gas Reference Network Aircraft Program relative to trends observed at Mauna Loa Observatory. The analyzed measurements of air samples in specially fabricated flask packages frequencies days months 22 sites continental shipped back Boulder, Colorado, analysis. These calibrated World Meteorological...
Significance Rising arctic temperatures could mobilize reservoirs of soil organic carbon trapped in permafrost. We present the first quantitative evidence for large, regional-scale early winter respiration flux, which more than offsets uptake summer Arctic. Data from National Oceanic and Atmospheric Administration’s Barrow station indicate that October through December emissions CO 2 surrounding tundra increased by 73% since 1975, supporting view rising have made Arctic ecosystems a net...