Open AccessModel analysis of trace gas measurements and pollution impact during INDOEX
Author(s) -
Laat A. T. J.,
Gouw J. A.,
Lelieveld J.,
Hansel A.
Publication year - 2001
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2000jd900821
Subject(s) - troposphere , acetonitrile , acetone , stratosphere , atmospheric sciences , environmental science , sink (geography) , trace gas , planetary boundary layer , climatology , chemistry , boundary layer , geology , thermodynamics , chromatography , physics , organic chemistry , cartography , geography
An analysis of acetone (CH 3 COCH 3 ) and acetonitrile (CH 3 CN) measurements, performed during the Indian Ocean Experiment (INDOEX), using a chemistry general circulation model is presented. A comparison with measurements indicates that the model simulates realistic CO and acetone distributions, except toward the Indian west coast near the surface. The latter may be related to a sea breeze circulation at the Indian west coast, which is not resolved by the model. A comparison of the measured and modeled correlation between CO and acetone indicates the presence of a background marine acetone source. A model sensitivity study suggests a global marine emission strength of 15–20 Tg acetone yr −1 , which is a significant contribution to the estimated global acetone source of 56 (37–80) Tg acetone yr −1 . The comparison of measured and modeled CO‐acetonitrile correlation from surface measurements indicates that a model sink of acetonitrile in the marine boundary layer is missing. A model sensitivity study suggests that this could be dry deposition (deposition velocity estimate: 0.01–0.05 cm s −1 ) on the ocean surface. A comparison of measured and modeled tropospheric acetonitrile indicates that the model overestimates the free tropospheric acetonitrile mixing ratios up to a factor of 3, which points to a missing free tropospheric sink of acetonitrile in the model. A possible explanation may be stratospheric loss and subsequent stratosphere‐troposphere exchange, which was not included in the model.