基于FY-3C/VIRR海温资料的超强厄尔尼诺演变过程诊断分析

Diagnostic Analysis of Super-El Niňo Based on FY-3C/VIRR Sea Surface Temperature Data Sets

为了定量评估FY-3C卫星可见光红外扫描辐射计的海表面温度(SST)产品数据在厄尔尼诺事件分析中的可用性,利用FY-3CSST产品数据对2014/2016年超强厄尔尼诺形成、发展的时空演变过程进行诊断分析,并与气候态分析中常用的美国气象环境预报中心(NCEP)和美国国家大气研究中心(NCAR)联合制作的最优插值海表温度(OISST)资料进行对比评估。研究认为:FY-3C/VIRR月均海温数据能够刻画出厄尔尼诺期间海表面温度异常升高的基本时空分布特征;FY-3C/VIRRSST与OISST资料相比,海温距平场振幅变化范围较小,FY-3C/VIRRSST全样本资料在进行重采样及异常值剔除处理后的气候特征分析效果更好,在具体应用海温产品时可根据应用目标选取高产品等级像元参与运算;中高纬度与赤道低纬度的海温距平存在区域偏差现象,具体表现为FY-3CSST中高纬度海温暖异常值相比OISST偏高,赤道中东太平洋海温暖异常值相对OISST偏低,全局回归系数的代表性是造成这种区域偏差现象出现的主要原因,为FY-3CSST海温资料在气候态分析中的应用提供了借鉴,并为海温资料的进一步完善提供了改进建议。

For evaluating the availability of FY-3C/VIRR SST (visible infrared radiometer sea surface temperature) data sets when analyzing the El Ni o events,generation and evolution of El Ni o events happened in 2014/2016 are analyzed by using FY-3C/VIRR and NCEP/NCAR (optimum interpolation sea surface temperature,OISST) data sets. Results indicate that the spatial distribution and evolution of anomalous warming in El Ni o events can be depicted by FY-3C/VIRR SST data sets. Compared with the OISST,FY-3C/VIRR SST is associated with smaller amplitude. For improving the efficiency of information extraction,resampling and removing outlier from full-sample FY-3C/VIRR SST data sets and selecting high-level pixels associated with high-quality to participate in the calculation are preferred in the climatic analyzing. In addition,regional deviation is detected in the SST anomalies between mid-high and low latitude areas. Amplitude of sea surface temperature anomalies in mid-high (low) latitude areas is higher (lower) in FY-3C/VIRR SST than OISST data sets. The use of the global regression coefficient in FY-3C/VIRR SST data sets can be responsible for the regional deviation of amplitude in mid-high and low latitude areas. In general,this paper provides the reference for researchers to analyze climate events based on FY-3C SST data sets and proposes the improvement suggestions for FY-3C SST data sets.