A preliminary study on Geosat altimeter observation in the Southern Ocean

• Main Authors: Takashi Kikuchi, Akira Shibata, Masaaki Wakatsuchi
• Format: Report
• Language: English
• Published: Institute of Low Temparature Science, Hokkaido University 1993
• Subjects: Antarctic; Drake Passage; New Zealand; Southern Ocean; The Antarctic; Antarc*; Polar meteorology and glaciology; Proceedings of the NIPR Symposium on Polar Meteorology and Glaciology
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=3778; http://id.nii.ac.jp/1291/00003778/; https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=3778&item_no=1&attribute_id=18&file_no=1

The Geosat sea-level anomaly in the Southern Ocean south of 30°S in the period from November 1986 to December 1987 is calculated by pplying the collinear method to retrieve sea-level from the Geosat altimeter data. The Geosat sea-level data are used to investigate the variation and time-dependancy in sea-level anomaly in the Southern Ocean.Regions with high variability in sea-level anomaly correspond to the confluence zones of subtropical and subantarctic water and to the Antarctic Circumpolar Current(ACC). Two regions with higher variability exist in the ACC. High variability south of New Zealand is closely irelated to the bottom topography. The sea-level anomaly in this region does not show a clear propagation ignal, while the strong anomaly generated in Drake Passage propagates down stream at a speed of 4.5 cm/s. In the southern regions of the ACC we were not able to find any significant variation of the Geosat sea-level data. time-dependency of sea-level variation along a latitude of 40°S suggests that the Agulhas eddies are generated near 30°S and move westward at a speed of 10-15 cm/s.