Ozone transport by mesoscale convective storms in western Senegal

被引:27
作者
Grant, Deanne D.
Fuentes, Jose D.
DeLonge, Marcia S.
Chan, Stephen
Joseph, Everette [1 ]
Kucera, Paul [2 ]
Ndiaye, Seydi A. [3 ]
Gaye, Amadou T. [3 ]
机构
[1] Howard Univ, Dept Phys, Washington, DC 20059 USA
[2] NCAR, Boulder, CO USA
[3] UCAD, Lab Phys Atmospher & Ocean Simeon Fongang, Ecole Super Polytech, Dakar, Senegal
关键词
Ozone; Convection; Dry deposition; Ozone fluxes; Boundary layer;
D O I
10.1016/j.atmosenv.2008.05.044
中图分类号
X [环境科学、安全科学];
学科分类号
08 ; 0830 ;
摘要
During the rainy period of August and September 2006, a study was conducted to investigate the prevailing diurnal patterns of ozone in rural western Senegal. Ground-level ozone was continuously measured with gas analyzers. During selected days, ozone and atmospheric thermodynamic measurements were also made in the troposphere. Ground-level ozone exhibited diurnal variations in response to the local photochemical processes and vertical transport. Maximum ground-level ozone mixing ratios reached 30 parts per billion on a volume basis (ppbv) during 1200-1600 h, local time. Deviations from the expected diurnal ozone patterns were observed during most rainy days. The observed deviations were manifested as ozone increases which were associated with downdrafts of mesoscale convective storms. The magnitude of the ozone increases depended on the strength of convective velocities which exceeded 10 m s(-1). Downdrafts increased the ground-level ozone by 10-30 ppbv. Based on field observation in Senegal and elsewhere, a conceptual model is presented to explain the influences of convective storms on the redistribution of ozone in the continental troposphere. 2008 Elsevier Ltd. All rights reserved.
引用
收藏
页码:7104 / 7114
页数:11
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