 |
| Titel |
Transport of aerosols into the UTLS and their impact on the Asian monsoon region as seen in a global model simulation |
| VerfasserIn |
S. Fadnavis, K. Semeniuk, L. Pozzoli, M. G. Schultz, S. D. Ghude, S. Das, R. Kakatkar |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 13, no. 17 ; Nr. 13, no. 17 (2013-09-03), S.8771-8786 |
| Datensatznummer |
250085670
|
| Publikation (Nr.) |
 copernicus.org/acp-13-8771-2013.pdf |
|
|
|
|
|
| Zusammenfassung |
| An eight-member ensemble of ECHAM5-HAMMOZ simulations for a boreal summer
season is analysed to study the transport of aerosols in the upper
troposphere and lower stratosphere (UTLS) during the Asian summer monsoon
(ASM). The simulations show persistent maxima in black carbon, organic
carbon, sulfate, and mineral dust aerosols within the anticyclone in the
UTLS throughout the ASM (period from July to September), when convective
activity over the Indian subcontinent is highest, indicating that boundary
layer aerosol pollution is the source of this UTLS aerosol layer. The
simulations identify deep convection and the associated heat-driven
circulation over the southern flanks of the Himalayas as the dominant
transport pathway of aerosols and water vapour into the tropical tropopause
layer (TTL). Comparison of model simulations with and without aerosols
indicates that anthropogenic aerosols are central to the formation of this
transport pathway. Aerosols act to increase cloud ice, water vapour, and
temperature in the model UTLS. Evidence of ASM transport of aerosols into
the stratosphere is also found, in agreement with aerosol extinction
measurements from the Halogen Occultation Experiment (HALOE) and
Stratospheric Aerosol and Gas Experiment (SAGE) II. As suggested by the
observations, aerosols are transported into the Southern Hemisphere around
the tropical tropopause by large-scale mixing processes. Aerosol-induced
circulation changes also include a weakening of the main branch of the
Hadley circulation and a reduction of monsoon precipitation over India. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|