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International Journal of Marine Science 2013, Vol.3, No.18, 145-150
http://ijms.sophiapublisher.com
145
Research Article Open Access
Long-term Changes in Sea Surface Temperature at Selected Locations in the
Sea of Oman and the Arabian Sea off Oman
Y.V.B. Sarma
1
, Anesh Govender
1
, Ebenezer S. Nyadjro
2
, Sergey Piontkovski
1
1. College of Agricultural and Marine Science, Sultan Qaboos University, P.O. Box.34, Al Khod, P.C. 123, Muscat, Oman
2. NOAA Pacific Marine Environmental Laboratory, 7600 Sandpoint Way NE, Seattle, WA 98115, USA
Corresponding author email: sarma@squ.edu.om
International Journal of Marine Science, 2013, Vol.3, No.18 doi: 10.5376/ijms.2013.03.0018
Received: 08 Apr., 2013
Accepted: 19 Apr., 2013
Published: 22 Apr., 2013
Copyright
©
2013 Sarma, This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted use,
distribution, and reproduction in any medium, provided the original work is properly cited.
Preferred citation for this article:
Sarma et al, 2013, Long-term Changes in Sea Surface Temperature at Selected Locations in the Sea of Oman and the Arabian Sea off Oman, International
Journal of Marine Science, Vol.3, No.18 145
-
150 (doi: 10.5376/ijms.2013.03.0018)
Abstract
Long-term changes in the sea surface temperature (SST) at two locations off Oman were investigated using Hadley
Center SST for the period 1961~2009. A mean annual increase in SST by 0.32
℃
was noticed in the Sea of Oman while an increase
of 0.53
℃
was noticed in the western Arabian Sea. The shift in SST is higher off Muscat than off Masirah during the study period.
The bi-modal variability of the SST in the study region is successfully simulated by a cyclic model developed utilizing SST data for
1961~2009 period. An increase in summer warming and decrease in winter cooling are evident in the annual SST distribution at both
the locations. The decadal variability off Masirah in the western Arabian Sea showed that the standard deviation of SST switched its
character post-1990. The SST variance in Sea of Oman showed a decadal-scale change but in western Arabian Sea, it was nearly
unchanged until 1990 and rapidly declined post-1990 period. The large shifts in SST apparently caused higher variability in the sea
surface height (SSH) anomalies post-1990 period.
Keywords
Sea of Oman; Western Arabian Sea; Sea surface temperature; Sea level changes; Long-term SST change
Introduction
Sea surface temperature (SST) is an important
oceanographic variable as it provides the basis for sea
level and climate change studies. Regime shifts in
SST are noticed worldwide and are characterized by
an abrupt transition from one quasi-steady climatic
state to another. The transition period being much
shorter than the lengths of the individual epochs of
each climatic state and tend to impact the other
dynamics such as biological processes (Yasunaka and
Hanawa, 2002; 2005). The seasonal nature of the SST
in the Arabian Sea is bi-modal while in the Sea of
Oman, it is unclear, but reported to be largely
uni-modal (Colborn, 1971). The Indian Ocean experienced
anomalous warming in 1976~1977 indicating an
abrupt shift in climate (Nitta and Yamada, 1989; Aoki
et al., 2003; Terray and Dominiak, 2005). Khan et al
(2004, 2008) reported an increasing trend of SST in
the Arabian Sea over the period 1985~1998 and
argued that the northern coast of Oman in the Sea of
Oman and the east coast of Oman in the northwestern
Arabian Sea exhibited different time scales of
inter-annual and seasonal variability of the SST.
Anomalous and persistent increase in SST during
early summer by about 2
℃
off Masirah Island as well
as in the Sea of Oman was noticed before the severe
cyclones
“
Gonu
”
in 2007, and
“
Phet
”
in 2010 made
landfall along the east coast of Oman (Sarma, 2011).
Long-term trends in SST variability in the Sea of
Oman and the northwestern Arabian Sea along Oman
are largely under-investigated till date. In this study,
we investigated the SST variability at two locations
along Oman, which have different warming and
cooling patterns. A cyclic model was developed to
simulate the bi-modal nature of the seasonal SST
changes and the long-term trend in SST at the two
selected locations. Further, the SST anomalies (SSTA)
at the study locations are compared with sea surface
height anomalies (SSHA) to examine the impact of
the SST changes on sea level changes at the selected
locations.
2 Data and Methods
Sea surface temperature (SST) over a one degree-square
at two locations; Muscat (23~24°N, 59~60°E) in Sea
of Oman and Masirah Island (19~20°N, 58~59°E) in