近35a南海海-气温差不同资料比对及变化特征分析

COMPARATIVE ANALYSIS ON DIFFERENT DATA OF AIR-SEA TEMPERATURE DIFFERENCE AND ANALYSIS ON VARIATION CHARACTERISTICS FOR SOUTH CHINA SEA IN THE PAST 35 YEARS

基于ICOADS、ERA-Interim 2种资料,对近35 a南海海-气温差空间分布进行比对,并使用经验正交分解及小波分析讨论了该区域海-气温差的时空分布变化特征。结果表明:ICOADS及ERA-Interim资料均可反映南海海-气温差的实际分布,但同一区域内ERA-Interim下的海-气温差数值较ICOADS偏低,且ERA-Interim在近岸特征不明显;南海南北部海-气温差呈跷跷板型变化,4、5月达南负北正峰值,11月达南正北负峰值;夏、秋季南海海-气温差的年际变化呈波动下降趋势,夏季海-气温差在北部湾与南海主体海域间呈跷跷板关系,秋季南沙群岛海域存在明显海-气温差高值区;四个季节南海海-气温差准3 a振荡周期显著,冬、春季还具有准11 a振荡周期;海-气温差与夏、秋季Ni?o3.4指数呈正相关,冬、春季呈负相关。

Using the ICOADS and ERA-Interim data, the spatial distribution characteristics of air-sea temperature difference（ASTD） in the South China Sea（SCS） for the past 35 years are compared, and the variation characteristics of spatial and temporal distribution of ASTD in this region are discussed by using the empirical orthogonal function（EOF） decomposition and wavelet analysis methods. The results indicate that both ICOADS and ERA-Interim data can reflect the real distribution characteristics of ASTD in the SCS, but the value of ASTD with the ERA-Interim data is lower than that of the ICOADS data in the same region. In addition, the characteristics of ASTD are not obvious inshore with the ERA-Interim data. A seesaw type of north-south distribution of ASTD is dominant in the SCS： a positive peak in the south is associated with a negative peak in the north in November, while a negative peak in the south is accompanied with a positive peak in the north in April and May. The interannual variations of ASTD in summer or autumn are declining in fluctuation. There is a seesaw type distribution of ASTD between the Beibu Bay and the bulk part of the SCS in summer, and the center of high values is located in the Nansha Island area in autumn. The ASTD in the SCS has a significant quasi-3a oscillation period in all seasons, and it also has a quasi-11 a oscillation period in winter and spring. The ASTD is positively correlated with the Ni？o3.4 index in summer and autumn, but negatively correlated with the Ni？o3.4 index in spring and winter.