Abstract
The wind-stress field in the North Pacific Ocean during 1961–75 is computed from nearly five million ship reports. With a drag coefficient having a linear relation to wind speed, annual mean and monthly mean wind-stress fields are obtained, and their features are described.
Compared with the stress fields obtained byHellerman (1967) andWyrtki andMeyers (1976), the eastward component of the stress in the present study is larger in magnitude and the northward one smaller in magnitude, especially in the trade wind region. Differences in the drag coefficient do not have a pronounced effect on the estimated stress field. Long-period inter-annual variations in the wind field are the most likely cause of the discrepancies between the present study and those of the above authors.
The maximum of the wind-stress curl, estimated from the annual mean wind-stress fields, is as large as 1.0×10−8dyn cm−3 around 30°N, and is larger than that estimated byEvenson andVeronis (1975). The discrepancy is considered to be mainly due to differences in the computed stress field itself rather than due to differences in the grid size used in the stress computations.
The Sverdrup transports integrated from the eastern boundary on the basis of the present stress field have a maximum greater than 40×10−12cm3 s−1 (Sv.) near the western boundary around 30°N. This value is closer to the observed transport of the Kuroshio than that based on Hellerman's stress field.
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Kutsuwada, K. New computation of the wind stress over the North Pacific Ocean. Journal of the Oceanographical Society of Japan 38, 159–171 (1982). https://doi.org/10.1007/BF02110287
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DOI: https://doi.org/10.1007/BF02110287