Estimation of interbasin transport using ocean bottom pressure: Theory and model for Asian marginal seas

Abstract

The Asian Marginal Seas are interconnected by a number of narrow straits, such as the Makassar Strait connecting the Pacific Ocean with the Indian Ocean, the Luzon Strait connecting the South China Sea with the Pacific Ocean, and the Korea/Tsushima Strait connecting the East China Sea with the Japan/East Sea. Here we propose a method, the combination of the “geostrophic control” formula of Garrett and Toulany (1982) and the “hydraulic control” theory of Whitehead et al. (1974), allowing the use of satellite‐observed sea‐surface‐height (SSH) and ocean‐bottom‐pressure (OBP) data for estimating interbasin transport. The new method also allows separating the interbasin transport into surface and bottom fluxes that play an important role in maintaining the mass balance of the regional oceans. Comparison with model results demonstrates that the combined method can estimate the seasonal variability of the strait transports and is significantly better than the method of using SSH or OBP alone.

Circulation and oxygenation of the glacial South China Sea

“…Meanwhile, results demonstrate that winter season net westward through LS is ca. 3.8 10 times higher than summer season, and this is consistent with plenty of field observations (Lan et al, 2004), and numerical models carried out in the LS (Fang et al, 2005;Song, 2006;Yaremchuk et al, 2009;Zhao et al, 2009b). For the LSL condition with doubled wind speed enforcement (HQSK2), increased westward transport results in a residence time of 18.4 years, which is nearly the same as that of the PSL condition.…”

Sub-seasonal variability of Luzon Strait Transport in a high resolution global model

“…Although the agreement that the Kuroshio mainly inflows into SCS at the Luzon Strait has been reached (Li and Wu , 1989;Liang et al, 2008), estimation of the mean LST into the SCS in different papers still have big differences, varying from 0.5 to 10 Sv (Wyrtki, 1961;Metzger and Hurlburt, 1996;Lebedev and Yaremchuk, 2000;Chu and Li, 2000;Xue et al, 2004;Yaremchuk and Qu, 2004;Song, 2006;Wang et al, 2006;Yu et al, 2007). The big differnces between these estimates may be caused by time-scale and precision of the observations, data processing methods, numerical model settings and other factors.…”

Transport and Dynamics of the Panay Sill Overflow in the Philippine Seas*

“…Qu and Song (2009) published estimates of Mindoro Strait transport using satellite-derived sea surface height and ocean bottom pressure measurements. Their model was based on rectangular hydraulic control theory and geostrophic control (Whitehead 1989;Garrett and Toulany 1982;Song 2006) to estimate a full-watercolumn transport of 2.4 Sv and a bottom-layer transport of 1.3 Sv. Although we do not estimate the full water column transport here, our bottom layer estimates are significantly lower, 0.3 versus 1.3 Sv.…”