Some characteristics of summer ocean structure off the Queen Maud Land, Antarctica

• Main Authors: Nobuo Ono, Tatsuo Motoi
• Format: Report
• Language: English
• Published: The Institute of Low Temperature Science, Hokkaido University 1983
• Subjects: Antarctic; Austral; Weddell; Queen Maud Land; Orcadas; Antarc*; Antarctica; Memoirs of National Institute of Polar Research; Polar Research
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=1507; http://id.nii.ac.jp/1291/00001507/; https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=1507&item_no=1&attribute_id=18&file_no=1

The hydrographic data of FUJI (Japanese Antarctic Research Expedition : JARE) obtained in the austral summers of 1966-1969 and 1973-1975 in a sector of 60°-70°S and 30°W-15°E, where the Weddell polynya appeared during the winters of 1973-1977,are examined for finding out the influence of a winter polynya on summer ocean structure, in comparison with the cruise-12 data of the ARA ISLAS ORCADAS obtained in the same sector in the austral summer of 1977. The vertical profiles of temperature, salinity and sigma-t at station 75-7 (67°27′S, 2°04′E) on February 26,1975,for the JARE-16 show anomalous characteristics featuring the absence of water below 0℃, both the weak minimum and the weak maximum temperature profile, a high-salinity water at the depth where the temperature is minimum, and a shallow picnocline. These features, which reveal the upward movement of saline water, are different from the anomalous features at station 115 of the cruise of the ISLAS ORCADAS, where the sinking of the cooled surface water occurred, as explained by GORDON (J. Phys. Oceanogr., 8,600,1978) and KILLWORTH (J. Phys. Oceanogr., 9,531,1979). The same features as the profiles at stations 75-7 and 115 are found at stations 118 and 125 respectively in the ISLAS ORCADAS data. These four stations were located near the margin of the polynya in the preceding winter, and both types of anomalous features reveal that strong convection, which occurred locally in the polynya area in the preceding winter, influences summer ocean structure.