浪致混合对2016年北太平洋海表温度季节性预测的影响

Effect of wave-induced mixing on sea surface temperature seasonal prediction in the North Pacific in 2016

上层海洋通过海气交换影响大气-海洋耦合系统,海浪引起的垂向混合影响上层海洋结构,从而在气候预测过程中发挥着重要的作用。本文基于国家海洋局第一海洋研究所地球系统模式(FIO-ESM),以2016年为例,分别开展了耦合和关闭海浪模式情况下的短期气候预测实验,分析浪致混合对北太平洋海表温度(SST)季节性预测的影响。通过对模式预测的SST异常(SSTA)进行定量评估发现,浪致混合能够显著降低北太平洋高纬度海区预测误差,在(45°N,150°E)附近海区SSTA改善可达1℃,气候模式能够更好地预测SSTA的经向分布特征,特别是能够准确地反映25°～45°N海区SSTA分布特征。通过分析有浪和无浪两个实验的热收支贡献发现,垂向混合是导致上层海洋温度差异的主导影响因子。海浪通过改变垂向混合,使2016年北太平洋SST在高纬度海区大幅降低,在低纬度海区略有升高,最终提升了模式对北太平洋SST的季节性预测能力。

The vertical mixing induced by waves affects the structure of the upper ocean,which dominates the atmosphere-ocean coupling system through air-sea exchanges.Hence waves have an important effect on climate prediction.Based on the First Institute of Oceanography Earth System Model(FIO-ESM),a group of prediction experiments are conducted.One of the experiments is coupled with the wave model and the other is not.The prediction results in 2016 are applied to study the effects of wave-induced mixing on the seasonal prediction of the North Pacific sea surface temperature(SST).Considering the wave-induced mixing,the prediction error is significantly reduced at high latitudes of the North Pacific.The predicted sea surface temperature anomaly(SSTA)can be improved by 1℃near(45°N,150°E).The climate model well predicts the meridional distribution of SSTA,especially the distribution characteristics during 25°-45°N.Then,the heat budgets of the two experiments are analyzed to find the reason for this improvement.The result indicates that the vertical mixing is the main influencing factor.The wave-induced mixing causes SST to reduce substantially at high latitudes and to increase slightly at low latitudes in 2016,which plays a key role in SST seasonal prediction in the North Pacific.