通过ICOADS (The International Comprehensive Ocean-Atmosphere Data Set)船测资料, 验证了El Ni?o引发的北印度洋(North Indian Ocean, NIO)海表温度(SST)的2次增暖过程。前人研究发现, 第1次增暖发生在El Ni?o盛期, 源于El Ni?o导致的大气环流变化产生了正的短波辐射及潜热通量异常; 第2次增暖发生在El Ni?o消亡的夏季, 是由于反对称风场异常导致蒸发失热减少所造成。 研究进一步发现, 短波辐射和潜热通量在这两次增暖中都有着重要作用, 但二者的作用在时间上并不一致。 两次增暖过程都是短波辐射首先产生影响, 其后才是风场导致的潜热通量的变化。两次增暖在东西两个海盆也存在差异, 第1次增暖主要集中在阿拉伯海区域, 第二次增暖在东西两个海盆都较明显。另外, 通过El Ni?o和La Ni?a对比发现, ENSO对北印度洋SST的影响具有不对称性。El Ni?o期间北印度洋产生2到3次增暖, 而La Ni?a只有第二年夏季的降温比较明显, 强度也比较弱。
The Sea Surface Temperature (SST) warming in the North Indian Ocean (NIO) is examined in terms of its association with ENSO using ICOADS monthly data for the period 1979?2007. The results indicate there are two SST warming periods in the NIO, occurring in El Ni?o developing year and decay year, respectively. The responses in the Arabian Sea and the Bay of Bengal are different. The change in surface heat fluxes related to ENSO is an important forcing to the NIO warming. The influences of shortwave radiation and latent heat flux are not simultaneous: the former is two or three months earlier than the latter. When the SST warms up in the NIO, the shortwave radiation turns to be a damping effect to the change in SST. Furthermore, the responses of SST in the NIO to El Ni?o and La Ni?a are asymmetric. During the El Ni?o, the SST increase displays two or three peaks. During the La Ni?a, only one significant cooling is formed over the NIO.
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