Evidence of change in the sea of okhotsk: Implications for the north pacific

Abstract

Russian data from five cruises during the period 1949 to 1952 are compared with observations taken during the World Ocean Circulation Experiment (WOCE) P1W in 1993 to examine changes which may have occurred in the Sea of Okhotsk during the latter half of the last century. A basin‐wide warming (0.1°‐0.3°C) and freshening (0.05–0.1 psu) of the Sea of Okhotsk was found to have occurred over the latter part of the 20th century. Since the Sea of Okhotsk is thought to be the major source for North Pacific Intermediate Water (NPIW), calculations were made to determine whether or not these changes in the Sea of Okhotsk water properties were consistent with evidence of large‐scale freshening of intermediate waters in the North Pacific. From several Okhotsk‐to‐Pacific salt flux calculations, we conclude that the Sea of Okhotsk was capable of causing the freshening noted in the NPIW over the past half century under certain assumed outflow conditions.