太平洋TIWs海表流场的年际变化及其动力机制

热带不稳定波（Tropical Instability Waves, TIWs）是热带太平洋最显著的中尺度海洋运动，是赤道中东太平洋特殊的信风海洋环流结构不稳定作用产生的独特动力现象，能直接影响当地海洋动力、生物地球化学和大气环境变化，对热带太平洋大尺度海洋环流和气候有重要的反馈作用。年际变化是热带太平洋的主要变化特征之一，显著影响TIWs的发生、发展和变化。但由于TIWs海流观测和诊断难度的限制，TIWs海流年际变化的研究较少，其变化特征和动力机制仍不清楚。本项目拟采用非平衡态海表流诊断模型，综合利用现有海表高度、海表温度、海面风场、赤道锚系阵列、Argo浮标等观测资料去诊断和描述TIWs海表流的年际变化特征，揭示其年际变化规律和背后的海气调节机制。该项目将有助于全面认识和监测TIWs动力变化，进一步理解TIWs与大尺度海洋环流和气候之间的跨尺度关系。

Tropical Instability Waves (TIWs) are the most prominent mesoscale ocean activities in the tropical Pacific, internally generated by the instability of the special, local wind-driven circulation structure. TIWs influence the local ocean dynamics, biogeochemistry and atmospheric variabilities, and play an important role in the large-scale ocean circulation and climate variabilities in the tropical Pacific via nonlinear feedbacks. Interannual variability is one of the dominant features of tropical Pacific Ocean, having a significant impact on the variability of TIWs. However, due to the difficulties of the TIW velocity observation and estimation, the interannual variability of the TIW velocity remains unclear and to be derived from the long records of satellite observations. Based on satellite and in-situ observations, the proposed project intends to use an unbalanced surface current diagnostic model to estimate the interannual variability of the TIW surface velocity, and reveal the dynamic mechanism of the variability. The project will help to fully understand and monitor the variability of TIW dynamics, and further clarify the cross-scale relationship between TIWs and the large-scale ocean circulation and climate variability.