Kathryn McKain
A5059253408- Atmospheric and Environmental Gas Dynamics
- Atmospheric chemistry and aerosols
- Atmospheric Ozone and Climate
- Air Quality Monitoring and Forecasting
- Cryospheric studies and observations
- Air Quality and Health Impacts
- Climate change and permafrost
- Methane Hydrates and Related Phenomena
- Hydrocarbon exploration and reservoir analysis
- Vehicle emissions and performance
- Climate variability and models
- Spectroscopy and Laser Applications
- Meteorological Phenomena and Simulations
- Ocean Acidification Effects and Responses
- Geochemistry and Geologic Mapping
- Marine and coastal ecosystems
- Atmospheric aerosols and clouds
- Peatlands and Wetlands Ecology
- Wind and Air Flow Studies
- Calibration and Measurement Techniques
- Fire effects on ecosystems
- Ionosphere and magnetosphere dynamics
- Forest ecology and management
- CO2 Sequestration and Geologic Interactions
- Remote Sensing and LiDAR Applications
Cooperative Institute for Research in Environmental Sciences
2015-2025
National Oceanic and Atmospheric Administration
2016-2025
University of Colorado Boulder
2016-2023
NOAA Earth System Research Laboratory
2018-2023
Harvard University Press
2012-2020
University of California, San Diego
2019
Ames Research Center
2019
Bay Area Environmental Research Institute
2019
NSF National Center for Atmospheric Research
2019
Langley Research Center
2019
We analyzed 13 years (1992−2004) of CO 2 flux data, biometry, and meteorology from a mixed deciduous forest in central Massachusetts. Annual net uptake ranged 1.0 to 4.7 Mg‐C ha −1 yr , with an average 2.5 . Uptake rates increased systematically, nearly doubling over the period despite age 75–110 years; there were parallel increases midsummer photosynthetic capacity at high light level (21.5−31.5 μ mole m −2 s ), woody biomass (101−115 1993−2005, mostly due growth one species, red oak), peak...
Significance Most recent analyses of the environmental impact natural gas have focused on production, with very sparse information emissions from distribution and end use. This study quantifies full seasonal cycle methane fractional contribution for urbanized region centered Boston. Emissions are found to be two three times larger than predicted by existing inventory methodologies industry reports. Our findings suggest that natural-gas–consuming regions may sources atmosphere is currently...
International agreements to limit greenhouse gas emissions require verification ensure that they are effective and fair. Verification based on direct observation of atmospheric concentrations will be necessary demonstrate estimated emission reductions have been actualized in the atmosphere. Here we assess capability ground-based observations a high-resolution (1.3 km) mesoscale transport model determine change over time from metropolitan region. We test method with network CO 2 surface...
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...
With the pending withdrawal of United States from Paris Climate Accord, cities are now leading US actions toward reducing greenhouse gas emissions. Implementing effective mitigation strategies requires ability to measure and track emissions over time at various scales. We report CO2 in Boston, MA, urban region September 2013 December 2014 based on atmospheric observations an inverse model framework. Continuous measurements five sites around Boston were combined with a high-resolution...
The hydroxyl radical (OH) fuels tropospheric ozone production and governs the lifetime of methane many other gases. Existing methods to quantify global OH are limited annual global-to-hemispheric averages. Finer resolution is essential for isolating model deficiencies building process-level understanding. In situ observations from Atmospheric Tomography (ATom) mission demonstrate that remote tightly coupled loss formaldehyde (HCHO), a major hydrocarbon oxidation product. Synthesis this...
Significance Understanding the sources of tropospheric ozone is important for effective air quality management and accurate radiative forcing attribution. Biomass burning emits large quantities precursors to lower atmosphere. This source can drive regional-scale production, but its impact on global poorly constrained. Here, we present unique in situ aircraft observations continental pollution tracers. Ozone enhancements attributable biomass equal or exceed those from urban emissions, a...
Abstract This article provides an overview of the NASA Atmospheric Tomography (ATom) mission and a summary selected scientific findings to date. ATom was airborne measurements modeling campaign aimed at characterizing composition chemistry troposphere over most remote regions Pacific, Southern, Atlantic, Arctic Oceans, examining impact anthropogenic natural emissions on global scale. These dominate chemical reactivity are exceptionally important for air quality climate. data provide in situ...
Abstract. The Total Carbon Column Observing Network (TCCON) measures column-average mole fractions of several greenhouse gases (GHGs) beginning in 2004 from over 30 current or past measurement sites around the world, using solar absorption spectroscopy near infrared region. TCCON GHG data have been used extensively for multiple purposes, including studies carbon cycle and anthropogenic emissions as well to validate improve observations made spacebased sensors. Here, we describe an update...
Abstract. The Total Carbon Column Observing Network (TCCON) measures column-average mole fractions of several greenhouse gases (GHGs), beginning in 2004, from over 30 current or past measurement sites around the world using solar absorption spectroscopy near-infrared (near-IR) region. TCCON GHG data have been used extensively for multiple purposes, including studies carbon cycle and anthropogenic emissions, as well to validate improve observations space-based sensors. Here, we describe an...
Abstract. Here we present a global and regionally resolved terrestrial net biosphere exchange (NBE) dataset with corresponding uncertainties between 2010–2018: Carbon Monitoring System Flux Net Biosphere Exchange 2020 (CMS-Flux NBE 2020). It is estimated using the NASA (CMS-Flux) top-down flux inversion system that assimilates column CO2 observations from Greenhouse Gases Observing Satellite (GOSAT) NASA's Observatory 2 (OCO-2). The regional monthly fluxes are readily accessible as tabular...
[Figure: see text].
Abstract. Ozone is a key constituent of the troposphere, where it drives photochemical processes, impacts air quality, and acts as climate forcer. Large-scale in situ observations ozone commensurate with grid resolution current Earth system models are necessary to validate model outputs satellite retrievals. In this paper, we examine measurements from Atmospheric Tomography (ATom; four deployments 2016–2018) HIAPER Pole-to-Pole Observations (HIPPO; five 2009–2011) experiments, two...
Significance Methane emissions from distribution and end use of natural gas (NG) are not well known. We analyzed atmospheric methane measurements to quantify NG in the Boston area over ∼8 y, finding approximately three times larger than calculated by usage-based inventories. observed no change 8 y despite efforts state address pipeline leaks. Seasonal directly related consumption NG, implying that sources other pipelines, such as transmission appliances, important may require future policy...
Urban areas contribute approximately three-quarters of fossil fuel derived CO2 emissions, and many cities have enacted emissions mitigation plans. Evaluation the effectiveness efforts will require measurement both emission rate its change over space time. The relative performance different estimation methods is a critical requirement to support efforts. Here we compare results including an inventory-based method two top-down atmospheric approaches implemented for Indianapolis, Indiana,...
Long-term atmospheric CO2 mole fraction and δ13CO2 observations over North America document persistent responses to the El Niño-Southern Oscillation. We estimate these corresponded 0.61 (0.45 0.79) PgC year-1 more American carbon uptake during Niño than La Niña between 2007 2015, partially offsetting increases of net tropical biosphere-to-atmosphere flux around Niño. Anomalies in derived ecosystem exchange (NEE) display strong but opposite correlations with surface air temperature seasons,...
Abstract Earth's atmosphere oxidizes the greenhouse gas methane and other gases, thus determining their lifetimes oxidation products. Much of this occurs in remote, relatively clean free troposphere above planetary boundary layer, where chemistry is thought to be much simpler better understood than it urban regions or forests. The NASA airborne Atmospheric Tomography study (ATom) was designed produce cross sections detailed atmospheric composition remote over Pacific Atlantic Oceans during...
Abstract. The global oxidation capacity, defined as the tropospheric mean concentration of hydroxyl radical (OH), controls lifetime reactive trace gases in atmosphere such methane and carbon monoxide (CO). Models tend to underestimate CO concentrations throughout troposphere, which is consistent with excessive OH. Approximately half non-methane volatile organic compounds (VOCs) thought occur over oceans where oxidant chemistry has received little validation due a lack observational...
Abstract. Characteristics of the Version 9 (V9) MOPITT (Measurements Pollution in Troposphere) satellite retrieval product for tropospheric carbon monoxide (CO) are described. The new V9 includes many CO retrievals over land which, previous versions, would have been discarded by cloud detection algorithm. Globally, number daytime has increased 30 %–40 % relative to 8 product, although increase coverage exhibits significant geographical variability. Areas benefiting from improved performance...
Pyrocumulonimbus (pyroCb) are wildfire-generated convective clouds that can inject smoke directly into the stratosphere. PyroCb have been tracked for years, yet their apparent rarity and episodic nature lead to highly uncertain climate impacts. In situ measurements of pyroCb reveal its distinctive exceptionally stable aerosol properties define long-term influence activity on stratospheric budget. Analysis 13 years airborne observations shows responsible 10 25% black carbon organic aerosols...
Abstract. Optimal estimation retrievals of trace gas total columns require prior vertical profiles the gases retrieved to drive forward model and ensure retrieval problem is mathematically well posed. For well-mixed gases, it possible derive accurate using an algorithm that accounts for general patterns atmospheric transport coupled with measured time series in questions. Here we describe used generate GGG2020, a new version GGG analyze spectra from solar-viewing Fourier transform...
The hydroxyl radical (OH) fuels atmospheric chemical cycling as the main sink for methane and a driver of formation loss many air pollutants, but direct OH observations are sparse. We develop evaluate an observation-based proxy short-term, spatial variations in (Proxy
Abstract Continuous measurements of atmospheric methane (CH 4 ) mole fractions measured by NOAA's Global Greenhouse Gas Reference Network in Barrow, AK (BRW), show strong enhancements above background values when winds come from the land sector July to December 1986 2015, indicating that emissions arctic tundra continue through autumn and into early winter. Twenty‐nine years little change seasonal mean CH enhancements, despite an increase annual temperatures 1.2 ± 0.8°C/decade (2 σ ). The...
Abstract The Southern Ocean plays a critical role in the global climate system by mediating atmosphere–ocean partitioning of heat and carbon dioxide. However, Earth models are demonstrably deficient Ocean, leading to large uncertainties future air–sea CO2 flux projections under warming incomplete interpretations natural variability on interannual geologic time scales. Here, we describe recent aircraft observational campaign, O2/N2 Ratio Airborne (ORCAS) study, which collected measurements...