海温异常对广东省极端暖冬影响的数值模拟研究

Numerical Simulation of the Impact of SSTA on Extreme Warm Winter in Guangdong

关键词:  极端暖冬  海温异常  数值模拟  东亚冬季风

Key words:  extreme warm winter  sea surface temperature anomalies  numerical simulation  East Asian winter monsoon

摘要:

基于广东省国家气象观测站数据、ERA5再分析资料和NOAA海温等数据，分析了广东省极端暖冬的气温分布特征和对应的大气环流状况，考察了与广东省极端暖冬相关的关键海区，并通过大气环流模式验证关键海区对广东省冬季温度的相对贡献。结果表明：广东省极端暖冬温度模态表现为全区一致偏暖分布型，温度正异常强度由南岭山脉向沿海一带递增，对应同期东亚冬季风强度明显偏弱。与广东冬季气温显著相关的海区主要分布在北太平洋、热带西太平洋、热带中东太平洋、热带印度洋和北大西洋。各海区海温单独强迫数值模拟结果表明，上述五个关键海区的海温均可造成广东的温度正异常，但各海区对暖冬的贡献大小存在差异。此外，单独去除各海区强迫的数值模拟结果表明，相比其他海区，热带西太平洋和北大西洋海温异常总体上对广东极端暖冬的贡献突出，两个关键海区的各自影响以及协同作用都对广东极端暖冬的产生发挥了重要影响。

Abstract:

Based on observation data from the Guangdong national meteorological stations, ERA5 reanalysis data, and NOAA sea surface temperature data, this study analyzes the temperature distribution characteristics and the corresponding atmospheric circulation conditions of extreme warm winters in Guangdong. The key regions of sea surface temperature anomalies (SSTA) related to extreme warm winters in Guangdong, and the relative contribution of key regions to winter temperatures in Guangdong via Atmospheric Circulation Climate Model (AGCM) experiments are also discussed. During the extreme warm winter in Guangdong, the surface temperature anomaly shows a uniform warming pattern throughout the whole region, with the intensity of positive temperature anomalies increasing gradually from the Nanling Mountains to the coastal areas, which corresponds to the weak intensity of the East Asian winter monsoon simultaneously. The SSTA correlated with winter temperatures in Guangdong are mainly distributed in the North Pacific, tropical western Pacific, tropical central-eastern Pacific, tropical Indian Ocean, and North Atlantic. By conducting AGCM experiments for each key region, it is found that the SSTAs in all five key regions cause positive temperature anomalies in Guangdong. But the contribution of each region to warm winters is different. Furthermore, sensitivity experiment removing the SSTA forcing of each key region separately demonstrate that, compared to other key regions, the overall contribution of SSTAs in the tropical western Pacific and North Atlantic to the extreme warm winter in Guangdong are prominent, highlighting that the independent and synergistic effects of the two key regions played an important role in the occurrence of the extreme warm winter in Guangdong.