Water exchange through the Kerama Gap estimated with a 25-year Pacific HYbrid Coordinate Ocean Model

作者：Zhou Wenzheng; Yu Fei^*; Nan Feng

来源：Chinese Journal of Oceanology and Limnology, 2017, 35(6): 1287-1302.

DOI：10.1007/s00343-017-6141-2

• Kerama Gap
• Kuroshio
• Ryukyu Current
• HYbrid Coordinate Ocean Model (HYCOM)
• water exchange

Variations in water exchange through the Kerama Gap (between Okinawa Island and Miyakojima Island) from 1979 to 2003 were estimated with the 0.08 degrees Pacific HYbrid Coordinate Ocean Model (HYCOM). The model results show that the mean transport through the Kerama Gap (KGT) from the Pacific Ocean to the East China Sea (ECS) was 2.1 Sv, which agrees well with the observed mean KGT (2.0 Sv) for 2009-2010. Over the time period examined, the monthly KGT varied from -10.9 Sv to 15.8 Sv and had a standard deviation of +/- 5.0 Sv. The water mainly enters the ECS via the subsurface layer (300-500 m) along the northeastern slope of the Kerama Gap and mainly flows out of the ECS into the southwest of the Kerama Gap. The seasonal and interannual variations of the KGT and the Kuroshio upstream transport were negatively correlated. The Kuroshio upstream transport was largest in summer and smallest in autumn while the KGT was smallest in summer (1.02 Sv) and largest in spring (2.94 Sv) and autumn (2.44 Sv). The seasonal and interannual variations in the Kuroshio downstream (across the PN-line) transport differed significantly from the Kuroshio upstream transport but corresponded well with the KGT and the sum of the transport through the Kerama Gap and the Kuroshio upstream, which indicates that information about variation in the KGT is important for determining variation in the Kuroshio transport along the PN-line.

• 出版日期2017-11
• 单位中国科学院大学; 中国科学院海洋研究所