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Convective transport and scavenging of peroxides by thunderstorms observed over the central U.S. during DC3
Author(s) -
Barth M. C.,
Bela M. M.,
Fried A.,
Wennberg P. O.,
Crounse J. D.,
St. Clair J. M.,
Blake N. J.,
Blake D. R.,
Homeyer C. R.,
Brune W. H.,
Zhang L.,
Mao J.,
Ren X.,
Ryerson T. B.,
Pollack I. B.,
Peischl J.,
Cohen R. C.,
Nault B. A.,
Huey L. G.,
Liu X.,
Cantrell C. A.
Publication year - 2016
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
eISSN - 2169-8996
pISSN - 2169-897X
DOI - 10.1002/2015jd024570
Subject(s) - scavenging , thunderstorm , chemistry , hydrogen peroxide , storm , environmental chemistry , meteorology , atmospheric sciences , organic chemistry , antioxidant , geology , physics
Abstract One of the objectives of the Deep Convective Clouds and Chemistry (DC3) field experiment was to determine the scavenging of soluble trace gases by thunderstorms. We present an analysis of scavenging of hydrogen peroxide (H 2 O 2 ) and methyl hydrogen peroxide (CH 3 OOH) from six DC3 cases that occurred in Oklahoma and northeast Colorado. Estimates of H 2 O 2 scavenging efficiencies are comparable to previous studies ranging from 79 to 97% with relative uncertainties of 5–25%. CH 3 OOH scavenging efficiencies ranged from 12 to 84% with relative uncertainties of 18–558%. The wide range of CH 3 OOH scavenging efficiencies is surprising, as previous studies suggested that CH 3 OOH scavenging efficiencies would be <10%. Cloud chemistry model simulations of one DC3 storm produced CH 3 OOH scavenging efficiencies of 26–61% depending on the ice retention factor of CH 3 OOH during cloud drop freezing, suggesting ice physics impacts CH 3 OOH scavenging. The highest CH 3 OOH scavenging efficiencies occurred in two severe thunderstorms, but there is no obvious correlation between the CH 3 OOH scavenging efficiency and the storm thermodynamic environment. We found a moderate correlation between the estimated entrainment rates and CH 3 OOH scavenging efficiencies. Changes in gas‐phase chemistry due to lightning production of nitric oxide and aqueous‐phase chemistry have little effect on CH 3 OOH scavenging efficiencies. To determine why CH 3 OOH can be substantially removed from storms, future studies should examine effects of entrainment rate, retention of CH 3 OOH in frozen cloud particles during drop freezing, and lightning‐NO x production.