A5001827638- Atmospheric and Environmental Gas Dynamics
- Atmospheric Ozone and Climate
- Atmospheric chemistry and aerosols
- Methane Hydrates and Related Phenomena
- Cryospheric studies and observations
- Geology and Paleoclimatology Research
- Air Quality Monitoring and Forecasting
- Ionosphere and magnetosphere dynamics
- Hydrocarbon exploration and reservoir analysis
- Climate variability and models
- Isotope Analysis in Ecology
- Meteorological Phenomena and Simulations
- Air Quality and Health Impacts
- Carbon Dioxide Capture Technologies
- Geophysics and Gravity Measurements
- Advanced Chemical Sensor Technologies
- Climate Change and Geoengineering
- Spectroscopy and Laser Applications
- Spacecraft and Cryogenic Technologies
- Lightning and Electromagnetic Phenomena
- Radioactive contamination and transfer
- Mass Spectrometry Techniques and Applications
- Superconducting Materials and Applications
- Winter Sports Injuries and Performance
- Atmospheric aerosols and clouds
University of Colorado Boulder
2017-2024
National Oceanic and Atmospheric Administration
2018-2024
Institute of Arctic and Alpine Research
2015-2024
NOAA Earth System Research Laboratory
2019-2023
Cooperative Institute for Research in Environmental Sciences
2019-2022
Abstract Urban emissions remain an underexamined part of the methane budget. Here we present and interpret aircraft observations six old leak‐prone major cities along East Coast United States. We use direct (CH 4 ), carbon dioxide (CO 2 monoxide (CO), ethane (C H 6 their correlations to quantify CH attribute natural gas. find five largest emit 0.85 (0.63, 1.12) Tg /year, which 0.75 (0.49, 1.10) /year is attributed Our estimates, include all thermogenic sources including end use, are more...
Permafrost and methane hydrates are large, climate-sensitive old carbon reservoirs that have the potential to emit large quantities of methane, a potent greenhouse gas, as Earth continues warm. We present ice core isotopic measurements (Δ14C, δ13C, δD) from last deglaciation, which is partial analog for modern warming. Our results show emissions in response deglacial warming were small (<19 teragrams per year, 95% confidence interval) argue against similar future also indicate biomass...
Abstract. The emissions of hydrofluorocarbons (HFCs) have increased significantly in the past 2 decades, primarily as a result phaseout ozone-depleting substances under Montreal Protocol and use HFCs their replacements. In 2015, large increases were projected HFC this century absence regulations, contributing up to 0.5 ∘C global surface warming by 2100. 2019, Kigali Amendment came into force with goal limiting globally, currently, regulations limit are effect several countries. Here, we...
In the Arctic and Boreal region (ABR) where warming is especially pronounced, increase of gross primary production (GPP) has been suggested as an important driver for atmospheric CO2 seasonal cycle amplitude (SCA). However, role GPP relative to changes in ecosystem respiration (ER) remains unclear, largely due our inability quantify these fluxes on regional scales. Here, we use carbonyl sulfide (COS) measurements provide observation-based estimates over North American ABR. Our annual...
Abstract. The hydroxyl radical (OH) largely determines the atmosphere's oxidative capacity and, thus, lifetimes of numerous trace gases, including methane (CH4). Hitherto, observation-based approaches for estimating atmospheric have primarily relied on using methyl chloroform (MCF), but as abundance MCF has declined, uncertainties associated with this method increased. In study, we examine use five hydrofluorocarbons (HFCs) (HFC-134a, HFC-152a, HFC-365mfc, HFC-245fa, and HFC-32) in...
Abstract The Montreal Protocol and its successive amendments have been successful in curbing emissions of ozone-depleting substances potent greenhouse gases via production/consumption controls. Here we show that the radiative forcing equivalent effective chlorine from hydrochlorofluorocarbons has decreased 61.75 mW m − 2 321.69 ppt, respectively, since 2021, 5 years before most recent projected decrease. This important milestone demonstrates benefits for mitigating climate change...
Global emissions of the ozone-depleting gas HCFC-141b (1,1-dichloro-1-fluoroethane, CH
Abstract We present a comparison of atmospheric transport model (ATM) simulations for carbonyl sulfide (COS), within the framework tracer intercomparison project “TransCom‐COS.” Seven ATMs participated in experiment and provided COS mixing ratios over years 2010–2018, using state‐of‐the‐art surface fluxes various components budget: biospheric sink, oceanic source, sources from fire industry. The main goal TransCom‐COS is to investigate impact uncertainty emission distribution simulating...
Abstract Despite the key role of Arctic in global Earth system, year-round in-situ atmospheric composition observations within are sparse and mostly rely on measurements at ground-based coastal stations. Measurements a suite trace gases were performed central during Multidisciplinary drifting Observatory for Study Climate (MOSAiC) expedition. These give comprehensive picture near-surface abundances greenhouse gases, i.e., carbon dioxide, methane, nitrous oxide, ozone, monoxide,...
Abstract Sulfuryl fluoride (SO 2 F ) is a synthetic pesticide and potent greenhouse gas that accumulating in the global atmosphere. Rising emissions are concern since SO has relatively long atmospheric lifetime high warming potential. The U.S. thought to contribute substantially emissions, but there paucity of information on how distributed across U.S., currently no inventory for or individual states. Here we provide an measurement-based estimate using high-precision measurements from NOAA...
We present measurements of CO mole fraction and stable isotopes (δ13CO δC18O) in air during the winters 2013–14 2014–15 at tall tower sampling sites around Indianapolis, USA. A located upwind city was used to quantitatively remove background signal, allowing for first unambiguous isotopic characterization urban source yielding 13CO –27.7 ± 0.5‰ VPDB C18O 17.7 1.1‰ VSMOW this source. use isotope measurements, results from a limited traffic study, as well atmospheric reaction rates examine...
We use global airborne observations of propane (C3H8) and ethane (C2H6) from the Atmospheric Tomography (ATom) HIAPER Pole-to-Pole Observations (HIPPO), as well U.S.-based aircraft tower by NOAA NCAR FRAPPE campaign tracers for emissions oil gas operations. To simulate mole fraction fields these gases, we update default emissions' configuration C3H8 used chemical transport model, GEOS-Chem v13.0.0, using a scaled C2H6 spatial proxy. With updated emissions, simulations both are in reasonable...
Abstract We present a comparison of atmospheric transport models that simulate carbonyl sulfide (COS). This is part II the ongoing Atmospheric Transport Model Inter‐comparison Project (TransCom–COS). Differently from I, we focus on seven model intercomparison by transporting two recent COS inversions NOAA surface data within TM5‐4DVAR and LMDz models. The main goals TransCom‐COS are (a) to compare simulations using sets optimized fluxes with use control scenario (part I) (b) evaluate...
Abstract. Atmospheric carbon monoxide (CO) is a key player in global atmospheric chemistry and regulated pollutant urban areas. Oxidation of volatile organic compounds (VOCs) an important component the CO budget has also been hypothesized to contribute substantially summertime budget. In principle, stable isotopic analysis could constrain magnitude this source. However, signature VOC-produced not well quantified, especially for oxygen isotopes. We performed measurements isotopes on air...
Abstract. Cosmic rays entering the Earth's atmosphere produce showers of secondary particles such as protons, neutrons, and muons. The interaction these with oxygen-16 (16O) in minerals ice quartz can carbon-14 (14C). In glacial ice, 14C is also incorporated through trapping 14C-containing atmospheric gases (14CO2, 14CO, 14CH4). Understanding production rates situ cosmogenic important to deconvolve signals both which contain valuable paleoenvironmental information. Unfortunately, by muons...
Abstract. The detection of increasing global CFC-11 emissions after 2012 alerted society to a possible violation the Montreal Protocol on Substances that Deplete Ozone Layer (MP). This alert resulted in parties MP taking urgent actions. As result, atmospheric measurements made 2019 suggest sharp decline emissions. Despite success and mitigation part this problem, regions fully responsible for recent emission changes have not yet been identified. Roughly two thirds (60 ± 40 %) increase...
Abstract. Measurements of carbon-14-containing carbon monoxide (14CO) in glacial ice are useful for studies the past oxidative capacity atmosphere as well reconstructing cosmic ray flux. The 14CO abundance represents combination trapped atmospheric and situ cosmogenic 14CO. systematics production retention not fully quantified, posing an obstacle to interpretation core measurements. Here we provide first comprehensive characterization at accumulation site (Summit, Greenland), including...
Oil and natural gas (O&G) production processing activities have changed markedly across the U.S. over past several years. However, impacts of these changes on air pollution greenhouse emissions are not clear. In this study, we examine ethane (C
Abstract. Atmospheric non-methane hydrocarbons (NMHCs) play an important role in the formation of secondary organic aerosols and ozone. After a multidecadal global decline atmospheric mole fractions ethane propane – most abundant NMHCs previous work has shown reversal this trend with increasing abundances from 2009 to 2015 Northern Hemisphere. These concentration increases were attributed unprecedented growth oil natural gas (O&amp;NG) production North America. Here, we supplement...
Abstract. Atmospheric non-methane hydrocarbons (NMHCs) play an important role in the formation of secondary organic aerosols and ozone. After a multidecade global decline atmospheric mole fractions ethane propane – most abundant NMHCs previous work has shown reversal this trend with increasing abundances from 2009 to 2015 Northern Hemisphere. These concentration increases were attributed unprecedented growth oil natural gas (O&amp;NG) production North America. Here, we supplement...
Ethane-based chlorofluorocarbons and hydrochlorofluorocarbons can have multiple isomers that are difficult to separate using gas chromatography with detection by electron capture (GC-ECD) or even mass spectrometry (GC-MS). Examples include CFC-113 CFC-113a; CFC-114 CFC-114a; CFC-112 CFC-112a; HCFC-124 HCFC-124a.&#160; As a result, atmospheric histories reported in the past most laboratories for more abundant isomer represent an ill-defined combination of both chemicals.&#160; This is...