Progress of Chinese research in physical oceanography of the Southern Ocean

Abstract

Oceanographic surveying has been one of the key missions of the Chinese National Antarctic Research Expeditionsince 1984. Using the field data obtained in these surveys and the results from remote sensing and numerical models, Chinesephysical oceanographers have investigated the water masses, fronts and circulation patterns in the Southern Ocean. The results ofnearly 30 years of research are summarized in this paper. Most oceanographic observations by Chinese researchers have been conductedin Prydz Bay and the adjacent seas. CTD (Conductivity Temperature and Depth) data, collected during the past 20 years,have been applied to study several features of the water masses in this region: The spatial variation of warm summer surface water,the northward extension of shelf water, the flow of ice shelf water from the cavity beneath the Amery Ice Shelf, the upwelling ofthe Circumpolar Deep Water, and the formation of the Antarctic Bottom Water. The circulation and its dynamic factors have beenanalyzed with dynamic heights calculated from CTD data as well as by numerical models. The structure and strength of the frontsin the southeast Indian Ocean and the Drake Passage were investigated with underway XBT/XCTD (Expendable Bathythermograph/Expendable CTD) and ADCP (Acoustic Doppler Current Profiler) data. Their interannual variations have been determinedand the factors of influence, especially the atmospheric forcing and mesoscale oceanic processes, were studied using remote sensingdata. The dynamic mechanism of the Antarctic Circumpolar Current (ACC) was analyzed by theoretical models. The transportand pattern of the ACC have been well reproduced by coupled sea ice-ocean models. Additional details of ACC variability wereidentified based on satellite altimeter data. The response of the ACC to climate change was studied using reanalysis data. Prospectsfor future research are presented at the end of this paper.