 |
| Titel |
A Match-based approach to the estimation of polar stratospheric ozone loss using Aura Microwave Limb Sounder observations |
| VerfasserIn |
N. J. Livesey, M. L. Santee, G. L. Manney |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 15, no. 17 ; Nr. 15, no. 17 (2015-09-04), S.9945-9963 |
| Datensatznummer |
250120016
|
| Publikation (Nr.) |
 copernicus.org/acp-15-9945-2015.pdf |
|
|
|
|
|
| Zusammenfassung |
| The well-established "Match" approach to quantifying chemical
destruction of ozone in the polar lower stratosphere is applied to
ozone observations from the Microwave Limb Sounder (MLS) on NASA's
Aura spacecraft. Quantification of ozone loss requires distinguishing
transport- and chemically induced changes in ozone abundance. This is
accomplished in the Match approach by examining cases where
trajectories indicate that the same air mass has been observed on
multiple occasions. The method was pioneered using ozonesonde
observations, for which hundreds of matched ozone observations per
winter are typically available. The dense coverage of the MLS
measurements, particularly at polar latitudes, allows matches to be
made to thousands of observations each day. This study is enabled by
recently developed MLS Lagrangian trajectory diagnostic (LTD) support
products. Sensitivity studies indicate that the largest influence on
the ozone loss estimates are the value of potential vorticity (PV)
used to define the edge of the polar vortex (within which matched
observations must lie) and the degree to which the PV of an air mass is
allowed to vary between matched observations. Applying Match
calculations to MLS observations of nitrous oxide, a long-lived tracer
whose expected rate of change is negligible on the weekly to monthly
timescales considered here, enables quantification of the impact of
transport errors on the Match-based ozone loss estimates. Our loss
estimates are generally in agreement with previous estimates for
selected Arctic winters, though indicating smaller losses than many
other studies. Arctic ozone losses are greatest during the 2010/11
winter, as seen in prior studies, with 2.0 ppmv (parts per million by
volume) loss estimated at 450 K potential temperature (~ 18 km
altitude). As expected, Antarctic winter ozone losses are
consistently greater than those for the Arctic, with less interannual
variability (e.g., ranging between 2.3 and 3.0 ppmv at 450 K). This
study exemplifies the insights into atmospheric processes that can be
obtained by applying the Match methodology to a densely sampled
observation record such as that from Aura MLS. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|