 |
| Titel |
The Arabian Sea as a high-nutrient, low-chlorophyll region during the late Southwest Monsoon |
| VerfasserIn |
S. W. A. Naqvi, J. W. Moffett, M. U. Gauns, P. V. Narvekar, A. K. Pratihary, H. Naik, D. M. Shenoy, D. A. Jayakumar, T. J. Goepfert, P. K. Patra, A. Al-Azri, S. I. Ahmed |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1726-4170
|
| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 7, no. 7 ; Nr. 7, no. 7 (2010-07-05), S.2091-2100 |
| Datensatznummer |
250004890
|
| Publikation (Nr.) |
 copernicus.org/bg-7-2091-2010.pdf |
|
|
|
|
|
| Zusammenfassung |
| Extensive observations were made during the late Southwest Monsoon of 2004
over the Indian and Omani shelves, and along a transect that extended from
the southern coast of Oman to the central west coast of India, tracking the
southern leg of the US JGOFS expedition (1994–1995) in the west. The data
are used, in conjunction with satellite-derived data, to investigate
long-term trends in chlorophyll and sea surface temperature, indicators of
upwelling intensity, and to understand factors that control primary
production (PP) in the Arabian Sea, focussing on the role of iron. Our
results do not support an intensification of upwelling in the western
Arabian Sea, reported to have been caused by the decline in the
winter/spring Eurasian snow cover since 1997. We also noticed, for the first
time, an unexpected development of high-nutrient, low-chlorophyll condition
off the southern Omani coast. This feature, coupled with other
characteristics of the system, such as a narrow shelf and relatively low
iron concentrations in surface waters, suggest a close similarity between
the Omani upwelling system and the Peruvian and California upwelling
systems, where PP is limited by iron. Iron limitation of PP may complicate
simple relationship between upwelling and PP assumed by previous workers,
and contribute to the anomalous offshore occurrence of the most severe
oxygen (O2) depletion in the region. Over the much wider Indian shelf,
which experiences large-scale bottom water O2-depletion in summer,
adequate iron supply from reducing bottom-waters and sediments seems to
support moderately high PP; however, such production is restricted to the
thin, oxygenated surface layer, probably because of the unsuitability of the
O2-depleted environment for the growth of oxygenic photosynthesizers. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|