基于GODAS数据的西太平洋暖池热状态特征及其对ENSO事件的影响

利用1981—2011年共31 a美国GODAS月平均次表层海温资料,以5~366 m次表层垂直平均海温表征上层海洋热含量(HC),运用合成、相关等统计学方法,分析了西太平洋暖池(以下简称暖池)热状态气候特征及其对ENSO事件的影响。结果表明:暖池区HC异常变化最大,异常变化最大的区域与其高值中心区域并不重合,而是在经向上向其两侧偏离;暖池区HC季节变化与SST季节变化高度一致,年际变率大于SST的年际变率;暖池热状态与ENSO事件有密切联系,最大冷(暖)异常恰好对应于ENSO循环过程中的El Ni1o(La Ni1a)事件,并且ENSO事件前期暖池HC存在明显东传信号。

Characterisitics of the West Pacific warm pool thermal condition and its effects on the ENSO events based on the GODAS data

By using the American Global Ocean Data Assimilation System (GODAS) monthly averaged subsurface temperature data from 1981 to 2011, the 5-366 m subsurface vertical average temperature was characterized as Heat Content(HC) to analyze the characterisitics of the West Pacific warm pool thermal condition and its effects on the ENSO with the synthetic, correlation analysis and other statistical methods. Results show that HC changes in the warm pool area was the biggest, which does not overlap with the high value center, but deviates to its two sides on the longitude direction. Its seasonal variation is highly consistent with Sea Surface Temperature (SST), but its interannual variability is greater than that of SST. The thermal condition of the warm pool is closely related with ENSO events, and the largest cold (warm) SST anomaly corresponds to the El Niño(La Niña) events in the process of ENSO cycle. Futhermore, a clear eastward signals of HC of the warm pool exists before the early ENSO events.