SAM Tropospheric Ozone

Kim J. H., S. Na, M. J. Newchurch, R. V. Martin (2005), Tropical tropospheric ozone morphology and seasonality seen in satellite and in situ measurements and model calculations, J. Geophys. Res., 110, D02303, doi:10.1029/2003JD004332. Full Text

Using the scan angle method the Northern Atlantic paradox is analyzed for its validity.  The scan angle method along with the GEOS-CHEM chemical transport model illustrates the seasonality seen with in situ ozone measurements.  However, this seasonality is not shown using the residual based method of tropospheric ozone retrieval.  Based upon this information it is concluded that the Northern Atlantic paradox does not actually exist.

Figure 4. Distribution of (a) fire counts from ATSR averaged for 1996–2000, (b) aerosol index from TOMS averaged for 1996–2000, (c) CO from MOPITT for 2000, (d) tropospheric ozone column (DU) from SAM averaged for 1996–2000, (e) tropospheric ozone column (DU) from CCD averaged for 1996–2000, and (f) tropospheric ozone column (DU) from GEOS-CHEM model for 1997 in the December-January-February time period.

The above figure illustrates that during the months of December, January, and February the residual based method of tropospheric ozone retrieval does not agree with the location of the ozone precursors as monitored by MOPITT.  Use of the scan angle method shows better agreement with the location of CO from MOPITT as well as the modeled tropospheric column ozone from GEOS-CHEM.