David Wilmouth's Publications

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...

Wilmouth, D.M., T.F. Hanisco, R.M. Stimpfle, and J.G. Anderson, Chlorine-Catalyzed Ozone Destruction: Cl Atom Production from ClOOCl Photolysis, J. Phys. CHem. A, 113, 14099-14108, doi:10.1021/JP9053204, 2009.

Recent laboratory measurements of the absorption cross sections of the ClO dimer, ClOOCl, have called into question the validity of the mechanism that describes the catalytic removal of ozone by chlorine. Here we describe direct measurements of the rate-determining step of that mechanism, the production of Cl atoms from the photolysis of ClOOCl, under laboratory conditions similar to those in the...

Wilmouth, D. M., R. M. Stimpfle, J. G. Anderson, J. W. Elkins, D. F. Hurst, R. J. Salawitch, and L. R. Lait (2006), Evolution of inorganic chlorine partitioning in the Arctic polar vortexJ. Geophys. Res.111, D16308, doi:10.1029/2005JD006951.

The first simultaneous, in situ atmospheric measurements of ClO, ClOOCl, ClONO2, and HCl, which together nearly compose total inorganic chlorine, Cl-y, were obtained using the NASA ER-2 aircraft, deployed from Kiruna, Sweden, during the SOLVE/THESEO mission. These chlorine measurements, along with Cly inferred from in situ measurements of organic chlorine source gases, offer an unprecedented...

Canty, T., E. D. Rivière, R. J. Salawitch, G. Berthet, J. -B. Renard, K. Pfeilsticker, M. Dorf, A. Butz, H. Bösch, R. M. Stimpfle, D. M. Wilmouth, E. C. Richard, D. W. Fahey, P. J. Popp, M. R. Schoeberl, L. R. Lait, and T. P. Bui, Nighttime OClO in the winter Arctic vortex. J. Geophys. Res.110, D01301, 2005, doi:10.1029/2004JD005035.

We show that a nighttime profile of OClO in the Arctic vortex during the winter of 2000 is overestimated, by nearly a factor of 2, using an isentropic trajectory model constrained by observed profiles of ClOx (ClO + 2 × ClOOCl) and BrO. Calculated abundances of nighttime OClO are shown to be sensitive to the abundance of BrOx (BrO + BrCl), details of the air parcel history during the...

Stimpfle, R. M., D. M. Wilmouth, R. J. Salawitch, and J. G. Anderson, The first measurements of ClOOCl in the stratosphere: The coupling of ClOOCl and ClO in the arctic polar vortex, J. Geophys. Res. 109, D03301, doi:10.1029/2003JD003811, February 4, 2004.

The first measurements of ClOOCl in the stratosphere have been acquired from a NASA ER-2 aircraft, deployed from Kiruna, Sweden (68°N, 21°E), during the joint SOLVE/THESEO-2000 mission of the winter of 1999/2000. ClOOCl is detected by thermal dissociation into two ClO fragments that are measured by the well-known technique of chemical conversion, vacuum ultraviolet resonance fluorescence. Ambient...

Davies, S., M. P. Chipperfield, K. S. Carslaw, B.-M. Sinnhuber, J. G. Anderson, R. M. Stimpfle, D. M. Wilmouth, D. W. Fahey, P. J. Popp, E. C. Richard, P. von der Gathen, H. Jost, and C. R. Webster, Modeling the effect of denitrification on Arctic ozone depletion during winter 1999/2000. J. Geophys. Res.108(D5), 8322, 2002, doi:10.1029/2001JD000445.

We have used the SLIMCAT three‐dimensional chemical transport model together with observations from the Stratospheric Aerosol and Gas Experiment (SAGE III) Ozone Loss and Validation Experiment (SOLVE) and the Third European Stratospheric Experiment on Ozone (THESEO 2000) to quantify the effect of denitrification on Arctic ozone loss. We have used two different denitrification schemes in the model...

Hanisco, T. F., J. B. Smith, R. M. Stimpfle, D. M. Wilmouth, K. K. Perkins, J. R. Spackman, J. G. Anderson, D. Baumgardner, B. Gandrud, C. R. Webster, S. Dhaniyala, K. A. McKinney, and T. P. Bui, Quantifying the rate of heterogeneous processing in the Arctic polar vortex with in situ observations of OH. J. Geophys. Res.107(D20), 8278, 2002, doi:10.1029/2001JD000425.

We present simultaneous in situ observations of OH, HO2, ClONO2, HCl, and particle surface area inside a polar stratospheric cloud undergoing rapid heterogeneous processing. A steady‐state analysis constrained by in situ observations is used to show that concentrations of OH calculated during a processing event are extremely sensitive to the assumptions regarding aerosol composition and...

Hanisco, T. F., J. B. Smith, R. M. Stimpfle, D. M. Wilmouth, J. G. Anderson, E. C. Richard, and T. P. Bui, In situ observations of HO2and OH obtained on the NASA ER-2 in the high-ClO conditions of the 1999/2000 Arctic polar vortex. J. Geophys. Res.107(D20), 8283, 2002, doi:10.1029/2001JD001024.

Extensive observations of OH and HO2 obtained aboard the NASA ER‐2 inside the Arctic polar vortex during the SAGE III Ozone loss and Validation Experiment (SOLVE) provide the opportunity to identify and test interferences during the measurement of HO2 in the presence of high concentrations of ClO. In‐flight calibrations are consistent with small interferences from CH3O2 (8%) and...

Wilmouth, D. M., T. F. Hanisco, N. M. Donahue, and J. G. Anderson, Fourier Transform ultraviolet spectroscopy of the A 23/2 ← X 23/2transition of BrO. J. Phys. Chem. A103, 8935–8945, 1999.

The first spectra of the A 2Π3/2 ← X 2Π3/2 electronic transition of BrO using Fourier transform ultraviolet spectroscopy are obtained. Broadband vibrational spectra acquired at 298 ± 2 K and 228 ± 5 K, as well as high-resolution rotational spectra of the A ← X 7,0 and 12,0 vibrational bands are presented. Wavenumber positions for the spectra are obtained with high accuracy,...

Pages