摘要
应用气候态月平均的Levitus和COADS(ComprehensiveOceanAtmosphereDataSet)温度资料及COADS海面通量资料,探讨了南海气候态意义下春季暖池(温度大于29.5℃的水体)的演变过程及其生消的动力学机制。研究发现,在气候态意义下,南海表层海温在5月份存在显著的增温,在南海中南部形成了大面积、具有一定厚度(约15m深)的春季暖池,暖池面积在6月份迅速减小以至消失。对南海春季暖池的生消机制研究发现,春季暖池的产生过程是由于在不断增长的海面净热通量的作用下,埃克曼抽吸导致的下降流有效地抑制了底部冷水的上涌,进而维持了海温的持续增暖;消亡过程则是由于局地涌升增强以及东南向的埃克曼流导致。以上的研究表明海洋动力因素在春季暖池形成及消亡过程中起着重要的作用。
The climatology monthly mean sea temperature from Levitus and Comprehensive Ocean-Atmosphere Data Set(COADS), and sea surface flux from COADS are used to study the formation and decay of spring warm pool in the South China Sea (SCS). In May, SST is rapidly increased and a large area of warm water(greater than 29.5℃) of the large area named spring warm pool appears in the central SCS, and its thickness is about 15 m. At that time, northeast monsoon is gradually weakened and disappears. As a result, the mixed layer depth becomes shallow, which means that the upper layer water is easier warmed than before. Spring warm pool decays in June when southwest monsoon prevails in the SCS and disappears in July. From the above, spring warm pool is a transient phenomenon in response to the atmosphere change, which influences SST variation by ocean dynamics. According to the upper mixed layer dynamical equation, the formation and the decay of spring warm pool are investigated here. It shows that the formation is due to increasing surface net heat flux and the downwelling caused by Ekman pumping, which effectively restrain the cold water upwelling and maintain the water warming. The decay of spring warm pool is because of local strengthening upwelling and southeast Ekman currents. All that means ocean dynamics plays the determinant roles in this process.
出处
《大气科学》
CSCD
北大核心
2005年第4期565-572,共8页
Chinese Journal of Atmospheric Sciences
基金
国家自然科学基金资助项目40306003
40376004
中国科学院知识创新工程项目KZCX3SW227
关键词
南海
春季暖池
海洋动力
the South China Sea, spring warm pool, ocean dynamics
