TY - JOUR
T1 - The Ekman temperature and salt fluxes at 8°30′N in the Arabian Sea during the 1995 southwest monsoon
AU - Chereskin, T. K.
AU - Wilson, W. D.
AU - Beal, L. M.
N1 - Funding Information:
The R.V. Knorr and R.V. Baldridge transects were supported by the National Science Foundation (NSF) and the National Oceanic and Atmospheric Administration (NOAA), respectively. We thank the chief scientists on I1 (Harry Bryden and John Morrison) and IR1 (Amy Ffield) for use of the CTD data, John Kindle for providing us with the NOGAPS wind data, and Carolyn Harris for help with some of the calculations. Margaret Yelland graciously provided us with results from the air-flow distortion study of the R.V. Knorr. The maps of sea level anomalies (MLSA) were generated by the AVISO group from TOPEX/POSEIDON and ERS satellite altimetry observations http://www-aviso.cls.cnes.fr . Comments from the anonymous reviewers improved the manuscript. Support from NSF Grants OCE94-13174 and OCE99-06776 is gratefully acknowledged.
Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2002
Y1 - 2002
N2 - The Arabian Sea Ekman transport is an important component of the meridional overturning circulation of the Indian Ocean. Chereskin et al. (Geophys. Res. Lett. 24 (1997) 2541) presented direct estimates of the Ekman transport across latitude 8°30′N in the Arabian Sea for June and September during the 1995 southwest monsoon. In this paper, we use these measurements to determine the Ekman depth and the resultant heat and salt fluxes. In June, at the monsoon onset, the Ekman temperature and salt fluxes were estimated to be southward, 2.4 ± 0.4 PW and 0.71 ± 0.1 × 109 kg s-1. The transport-weighted Ekman temperature and salinity were 29.0 ± 0.5°C and 35.31 ± 0.03 psu, not significantly different from surface values, 29.2°C and 35.28 psu, respectively. In September at the end of the monsoon, the Ekman temperature and salt fluxes had decreased in magnitude but were still southward, 0.77 ± 0.4 PW and 0.27 ± 0.1 × 109 kg s-1. The transport-weighted temperature, 25.8 ± 0.5°C, was 1.1°C colder than the surface value, and the transport-weighted salinity, 35.83 ± 0.03 psu, was not significantly different from the surface value of 35.86 psu. For this pair of sections, the top of the pycnocline appeared to be a better approximation for the Ekman depth than either the mixed layer or a fixed depth, and our estimates of the Ekman heat and salt fluxes were integrated from the surface to the top of the pycnocline. Although uncertainty in the Ekman mass transport dominates the error in the Ekman heat and salt fluxes, determining the Ekman depth is also important in estimating the Ekman contribution to the heat budget of the tropical Indian Ocean. A decrease in Ekman temperature by 1.1°C resulted in a 5% decrease in the temperature transport estimated for September.
AB - The Arabian Sea Ekman transport is an important component of the meridional overturning circulation of the Indian Ocean. Chereskin et al. (Geophys. Res. Lett. 24 (1997) 2541) presented direct estimates of the Ekman transport across latitude 8°30′N in the Arabian Sea for June and September during the 1995 southwest monsoon. In this paper, we use these measurements to determine the Ekman depth and the resultant heat and salt fluxes. In June, at the monsoon onset, the Ekman temperature and salt fluxes were estimated to be southward, 2.4 ± 0.4 PW and 0.71 ± 0.1 × 109 kg s-1. The transport-weighted Ekman temperature and salinity were 29.0 ± 0.5°C and 35.31 ± 0.03 psu, not significantly different from surface values, 29.2°C and 35.28 psu, respectively. In September at the end of the monsoon, the Ekman temperature and salt fluxes had decreased in magnitude but were still southward, 0.77 ± 0.4 PW and 0.27 ± 0.1 × 109 kg s-1. The transport-weighted temperature, 25.8 ± 0.5°C, was 1.1°C colder than the surface value, and the transport-weighted salinity, 35.83 ± 0.03 psu, was not significantly different from the surface value of 35.86 psu. For this pair of sections, the top of the pycnocline appeared to be a better approximation for the Ekman depth than either the mixed layer or a fixed depth, and our estimates of the Ekman heat and salt fluxes were integrated from the surface to the top of the pycnocline. Although uncertainty in the Ekman mass transport dominates the error in the Ekman heat and salt fluxes, determining the Ekman depth is also important in estimating the Ekman contribution to the heat budget of the tropical Indian Ocean. A decrease in Ekman temperature by 1.1°C resulted in a 5% decrease in the temperature transport estimated for September.
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U2 - 10.1016/S0967-0645(01)00168-0
DO - 10.1016/S0967-0645(01)00168-0
M3 - Article
AN - SCOPUS:0036222013
VL - 49
SP - 1211
EP - 1230
JO - Deep-Sea Research Part II: Topical Studies in Oceanography
JF - Deep-Sea Research Part II: Topical Studies in Oceanography
SN - 0967-0645
IS - 7-8
ER -