Publications

Anderson, J. G., D. K. Weisenstein, K. P. Bowman, C. R. Homeyer, J. B. Smith, D. M. Wilmouth, D. S. Sayres, J. E. Klobas, S. S. Leroy, J. A. Dykema, and S. C. Wofsy (2017), Stratospheric ozone over the United States in summer linked to observations of convection and temperature via chlorine and bromine catalysis, Proceedings of the National Academy of Sciences 114: E4905-E4913; doi: 10.1073/pnas.1619318114.

We present observations defining (i) the frequency and depth of convective penetration of water into the stratosphere over the United States in summer using the Next-Generation Radar system; (ii) the altitude-dependent distribution of inorganic chlorine established in the same coordinate system as the radar observations; (iii) the high resolution temperature structure in the stratosphere over the...

Sayres, D. S., R. Dobosy, C. Healy, E. Dumas, J. Kochendorfer, J. Munster, J. Wilkerson, B. Baker, and J. G. Anderson (2017), Arctic regional methane fluxes by ecotope as derived using eddy covariance from a low-flying aircraft, Atmos. Chem. Phys. 17(13): 8619-8633; doi: 10.5194/acp-17-8619-2017.

The Arctic terrestrial and sub-sea permafrost region contains approximately 30 % of the global carbon stock, and therefore understanding Arctic methane emissions and how they might change with a changing climate is important for quantifying the global methane budget and understanding its growth in the atmosphere. Here we present measurements from a new in situ flux observation system designed for...

Smith, J. B., D. M. Wilmouth, K. M. Bedka, K. P. Bowman, C. R. Homeyer, J. A. Dykema, M. R. Sargent, C. Clapp, S. S. Leroy, D. S. Sayres, J. M. Dean-Day, T. P. Bui, and J. G. Anderson (2017), A case-study of convectively sourced water vapor observed in the overworld stratosphere over the United States, J. Geophys. Res. Atmos. 122, doi:10.1002/2017JD026831.

On August 27, 2013, during the Studies of Emissions and Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys (SEAC4RS) field mission, NASA’s ER-2 research aircraft encountered a region of enhanced water vapor, extending over a depth of approximately 2 km and a minimum areal extent of 20,000 km2 in the stratosphere (375 K to 415 K potential temperature), south of the Great...

Klobas, J. E., D. M. Wilmouth, D. K. Weisenstein, J. G. Anderson, and R. J. Salawitch (2017), Ozone depletion following future volcanic eruptions, Geophys. Res. Lett. 44, 7490-7499; doi: 10.1002/2017GL073972.

While explosive volcanic eruptions cause ozone loss in the current atmosphere due to an enhancement in the availability of reactive chlorine following the stratospheric injection of sulfur, future eruptions are expected to enhance total column ozone as halogen loading approaches pre-industrial levels. The timing of this shift in the impact of major volcanic eruptions on the thickness of the ozone...

Dobosy, R., D. Sayres, C. Healy, E. Dumas, M. Heuer, J. Kochendorfer, B. Baker, and J. Anderson (2017), Estimating random uncertainty in airborne flux measurements over Alaskan tundra: Update on the Flux Fragment Method, J. Atmos. Oceanic Technol., in press; doi: 10.1175/JTECH-D-16-0187.1.

Airborne turbulence measurement gives a spatial distribution of air-surface fluxes that networks of fixed surface sites typically can not capture. Much work has improved the accuracy of such measurements and the estimation of the uncertainty peculiar to streams of turbulence data measured from the air. A particularly significant challenge and opportunity is to distinguish fluxes from different...

Canty, T. P.R. J. Salawitch, and D. M. Wilmouth (2016), The kinetics of the ClOOCl catalytic cycleJ. Geophys. Res. Atmos.12113,76813,783, doi:10.1002/2016JD025710.

We use simultaneous in situ observations of [ClO] and [ClOOCl] obtained in the Arctic polar vortex to evaluate the kinetics of the ClOOCl catalytic cycle. Available laboratory measurements of the ClOOCl absorption cross sections, the ClO + ClO + M reaction rate constant, and the ClO/ClOOCl equilibrium constant are considered, along with compendium evaluations of these...

J. B. Burkholder, S. P. Sander, J. Abbatt, J. R. Barker, R. E. Huie, C. E. Kolb, M. J. Kurylo, V. L. Orkin, D. M. Wilmouth, and P. H. Wine "Chemical Kinetics and Photochemical Data for Use in Atmospheric Studies, Evaluation No. 18," JPL Publication 15-10, Jet Propulsion Laboratory, Pasadena, 2015, http://jpldataeval.jpl.nasa.gov.

Anderson, J. G., D. M. Wilmouth, J. B. Smith, and D. S. Sayres, UV Dosage Levels in Summer: Increased Risk of Ozone Loss from Convectively Injected Water Vapor, Science 337, 835 (2012).

The observed presence of water vapor convectively injected deep into the stratosphere over
the United States can fundamentally change the catalytic chlorine/bromine free-radical chemistry of the lower stratosphere by shifting total available inorganic chlorine into the catalytically active free-radical form, ClO. This chemical shift markedly affects total ozone loss rates and makes
the catalytic...

Spackman, J. R., E. M. Weinstock, J. G. Anderson, D. F. Hurst, H.-J. Jost, and S. M. Schauffler (2007), Aircraft observations of rapid meridional transport from the tropical tropopause layer into the lowermost stratosphere: Implications for midlatitude ozoneJ. Geophys. Res.112, D12308, doi:10.1029/2006JD007618.

Meridional transport from the tropics redistributes ozone and water vapor at middle and high latitudes. In situ measurements of water vapor, CH4, and N2O, acquired aboard the NASA ER-2 aircraft during January-March 2000 in a campaign to survey the Arctic vortex, are used to examine transport into the lowermost stratosphere in the context of middle- and high-latitude ozone declines observed over...

Dobosy, R., E. J. Dumas, D. L. Senn, B. Baker, D. S. Sayres, M. F. Witinski, C. Healy, J. Munster, and J. G. Anderson (2012), Calibration and Quality Assurance of an Airborne Turbulence Probe in an Aeronautical Wind Tunnel, J. Atmos. Oceanic Technol. 30: 182-196; doi:10.1175/JTECH-D-11-00206.1.

The Best Aircraft Turbulence (BAT) probe is used by multiple research groups worldwide. To promote an accurate interpretation of the data obtained from the probe’s unusual nine-port design, a detailed understanding of the BAT probe’s function along with a characterization and minimization of its systematic anomalies is necessary. This paper describes recent tests to enhance understanding of...

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