 |
| Titel |
Overshooting of clean tropospheric air in the tropical lower stratosphere as seen by the CALIPSO lidar |
| VerfasserIn |
J.-P. Vernier, J.-P. Pommereau, L. W. Thomason, J. Pelon, A. Garnier, T. Deshler, J. Jumelet, J. K. Nielsen |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 11, no. 18 ; Nr. 11, no. 18 (2011-09-20), S.9683-9696 |
| Datensatznummer |
250010088
|
| Publikation (Nr.) |
 copernicus.org/acp-11-9683-2011.pdf |
|
|
|
|
|
| Zusammenfassung |
| The evolution of aerosols in the tropical upper troposphere/lower
stratosphere between June 2006 and October 2009 is examined using the
observations of the space borne CALIOP lidar aboard the CALIPSO satellite.
Superimposed on several volcanic plumes and soot from an extreme
biomass-burning event in 2009, the measurements reveal the existence of
fast-cleansing episodes in the lower stratosphere to altitudes as
high as 20 km. The cleansing of the layer, which extends from 14 to 20 km, takes place
within 1 to 4 months during the southern tropics convective season that
transports aerosol-poor tropospheric air into the lower stratosphere. In
contrast, the convective season of the Northern Hemisphere summer shows an
increase in the particle load at the tropopause consistent with a lofting of
air rich with aerosols. These aerosols can consist of surface-derived
material such as mineral dust and soot as well as liquid sulfate and organic
particles. The flux of tropospheric air during the Southern Hemisphere
convective season derived from CALIOP observations is shown to be 5 times at
16 km and 20 times at 19 km larger, respectively, than that associated with
flux caused by slow ascent through radiative heating. These results suggest
that convective overshooting is a major contributor to
troposphere-to-stratosphere transport with concomitant implications for the
Tropical Tropopause Layer top height, the humidity, the photochemistry and
the thermal structure of the layer. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|