 |
| Titel |
A review of the Match technique as applied to AASE-2/EASOE and SOLVE/THESEO 2000 |
| VerfasserIn |
G. A. Morris, B. R. Bojkov, L. R. Lait, M. R. Schoeberl |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 5, no. 9 ; Nr. 5, no. 9 (2005-09-28), S.2571-2592 |
| Datensatznummer |
250003077
|
| Publikation (Nr.) |
 copernicus.org/acp-5-2571-2005.pdf |
|
|
|
|
|
| Zusammenfassung |
| We apply the NASA Goddard Trajectory Model to data from a series of
ozonesondes to derive ozone loss rates in the lower stratosphere for the
AASE-2/EASOE mission (January-March 1992) and for the SOLVE/THESEO 2000
mission (January-March 2000) in an approach similar to Match. Ozone loss
rates are computed by comparing the ozone concentrations provided by
ozonesondes launched at the beginning and end of the trajectories connecting
the launches. We investigate the sensitivity of the Match results to the
various parameters used to reject potential matches in the original Match
technique. While these filters effectively eliminate from consideration
80% of the matched sonde pairs and >99% of matched observations in
our study, we conclude that only a filter based on potential vorticity
changes along the calculated back trajectories seems warranted. Our study
also demonstrates that the ozone loss rates estimated in Match can vary by
up to a factor of two depending upon the precise trajectory paths calculated
for each trajectory. As a result, the statistical uncertainties published
with previous Match results might need to be augmented by an additional
systematic error. The sensitivity to the trajectory path is particularly
pronounced in the month of January, for which the largest ozone loss rate
discrepancies between photochemical models and Match are found. For most of
the two study periods, our ozone loss rates agree with those previously
published. Notable exceptions are found for January 1992 at 475K and late
February/early March 2000 at 450K, both periods during which we generally
find smaller loss rates than the previous Match studies. Integrated ozone
loss rates estimated by Match in both of those years compare well with those
found in numerous other studies and in a potential vorticity/potential
temperature approach shown previously and in this paper. Finally, we suggest
an alternate approach to Match using trajectory mapping. This approach uses
information from all matched observations without filtering and uses a
two-parameter fit to the data to produce robust ozone loss rate estimates.
As compared to loss rates from our version of Match, the trajectory mapping
approach produces generally smaller loss rates, frequently not statistically
significantly different from zero, calling into question the efficacy of the
Match approach. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|