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Convective Distribution of Tropospheric Ozone and Tracers in the Central American ITCZ Region: Evidence from Observations During TC4During the Tropical Composition, Clouds and Climate Coupling (TC4) experiment that occurred in July and August of 2007, extensive sampling of active convection in the ITCZ region near Central America was performed from multiple aircraft and satellite sensors. As part of a sampling strategy designed to study cloud processes, the NASA ER-2, WB-57 and DC-8 flew in stacked "racetrack patterns" in convective cells. On July 24, 2007, the ER-2 and DC-8 probed an actively developing storm and the DC-8 was hit by lightning. Case studies of this flight, and of convective outflow on August 5, 2007 reveal a significant anti-correlation between ozone and condensed cloud water content. With little variability in the boundary layer and a vertical gradient, low ozone in the upper troposphere indicates convective transport. Because of the large spatial and temporal variability in surface CO and other pollutants in this region, low ozone is a better convective indicator. Lower tropospheric tracers methyl hydrogen peroxide, total organic bromine and calcium substantiate the ozone results. OMI measurements of mean upper tropospheric ozone near convection show lower ozone in convective outflow. A mass balance estimation of the amount of convective turnover below the tropical tropopause transition layer (TTL) is 50%, with an altitude of maximum convective outflow located between 10 and 11 km, 4 km below the cirrus anvil tops. It appears that convective lofting in this region of the ITCZ is either a two-stage or a rapid mixing process, because undiluted boundary layer air is never sampled in the convective outflow.
Document ID
20110007971
Acquisition Source
Goddard Space Flight Center
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Avery, Melody
(NASA Langley Research Center Hampton, VA, United States)
Twohy, Cynthia
(Oregon State Univ. Corvallis, OR, United States)
MCabe, David
(California Inst. of Tech. Pasadena, CA, United States)
Joiner, Joanna
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Severance, Kurt
(NASA Langley Research Center Hampton, VA, United States)
Atlas, Eliot
(Miami Univ. Miami, FL, United States)
Blake, Donald
(California Univ. Irvine, CA, United States)
Bui, T. P.
(NASA Ames Research Center Moffett Field, CA, United States)
Crounse, John
(California Inst. of Tech. Pasadena, CA, United States)
Dibb, Jack
(New Hampshire Univ. Durham, NH, United States)
Diskin, Glenn
(NASA Langley Research Center Hampton, VA, United States)
Lawson, Paul
(Spec, Inc. Boulder, CO, United States)
McGill, Matthew
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Rogers, David
(Oregon State Univ. Corvallis, OR, United States)
Sachse, Glen
(National Inst. of Aerospace Hampton, VA, United States)
Scheuer, Eric
(New Hampshire Univ. Durham, NH, United States)
Thompson, Anne M.
(Pennsylvania State Univ. University Park, PA, United States)
Trepte, Charles
(NASA Langley Research Center Hampton, VA, United States)
Wennberg, Paul
(California Inst. of Tech. Pasadena, CA, United States)
Ziemke, Jerald
(Maryland Univ. Baltimore County Baltimore, MD, United States)
Date Acquired
August 25, 2013
Publication Date
October 13, 2010
Publication Information
Publication: Journal of Geophysical Research Atmospheres
Volume: 115
Subject Category
Meteorology And Climatology
Distribution Limits
Public
Copyright
Other

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