|
Titel |
Seven year satellite observations of the mean structures and variabilities in the regional aerosol distribution over the oceanic areas around the Indian subcontinent |
VerfasserIn |
S. K. Nair, K. Parameswaran, K. Rajeev |
Medientyp |
Artikel
|
Sprache |
Englisch
|
ISSN |
0992-7689
|
Digitales Dokument |
URL |
Erschienen |
In: Annales Geophysicae ; 23, no. 6 ; Nr. 23, no. 6 (2005-09-15), S.2011-2030 |
Datensatznummer |
250015285
|
Publikation (Nr.) |
copernicus.org/angeo-23-2011-2005.pdf |
|
|
|
Zusammenfassung |
Aerosol distribution over the oceanic regions around the Indian subcontinent
and its seasonal and interannual variabilities are studied using the aerosol optical depth
(AOD) derived from NOAA-14 and NOAA-16 AVHRR data for the period of November
1995–December 2003. The air-mass types over this region during the Asian
summer monsoon season (June–September) are significantly different from
those
during the Asian dry season (November–April). Hence, the aerosol loading and
its properties over these oceanic regions are also distinctly different in
these two periods. During the Asian dry season, the Arabian Sea and Bay of
Bengal are dominated by the transport of aerosols from Northern Hemispheric
landmasses, mainly the Indian subcontinent, Southeast Asia and Arabia. This
aerosol transport is rather weak in the early part of the dry season
(November–January) compared to that in the later period (February–April).
Large-scale transport of mineral dust from Arabia and the production of
sea-salt aerosols, due to high surface wind speeds, contribute to the high
aerosol loading over the Arabian Sea region during the summer monsoon season.
As a result, the monthly mean AOD over the Arabian Sea shows a clear
annual cycle with the highest values occurring in July. The AOD over the Bay of
Bengal and the Southern Hemisphere Indian Ocean also displays an annual cycle
with maxima during March and October, respectively. The amplitude of the
annual variation is the largest in coastal Arabia and the least in the
Southern Hemisphere Indian Ocean. The interannual variability in AOD is the largest over
the Southeast Arabian Sea (seasonal mean AOD varies from 0.19 to 0.42) and the
northern Bay of Bengal (seasonal mean AOD varies from 0.24 to 0.39) during
the February–April period and is the least over the Southern Hemisphere Indian Ocean.
This study also investigates the altitude regions and pathways of dominant
aerosol transport by combining the AOD distribution with the atmospheric
circulation.
Keywords. Atmospheric composition and structure
(Aerosols and particles) – Meteorology and atmospheric
dynamics (Climatology) – Oceanography: physical (Ocean
fog and aerosols) |
|
|
Teil von |
|
|
|
|
|
|