Local and remote atmospheric response to tropical instability waves: A global view from space
Local and remote atmospheric response to tropical instability waves: A global view from space
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DOI：
10.1029/2000jd900684
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发表时间：
2001-05-27
影响因子：
4.4
通讯作者：
Takeuchi, K
中科院分区：
文献类型：
--
作者：
Hashizume, H;Xie, SP;Takeuchi, K
1999年在赤道太平洋发生了一次拉尼娜现象，并发展出强烈的热带不稳定波（TIWs），导致赤道和北纬3度之间的海表温度（SST）锋面出现大的弯曲。高分辨率的卫星测量被用来描述的SST，地面风速，柱集成的水汽，云液态水，和降水与这些强TIW在1999年的变化。在太平洋和大西洋都出现了连贯的海洋-大气模式，显示出丰富的区域特征。在远东太平洋，东南风贸易加强（减弱）的正（负）SST异常，显然是由于增强（减少）与高空高速风的混合。在中太平洋，我们发现的证据表明，SST引起的海平面压力的变化也大大有助于风的波动。南半球沿着2 ° S也存在类似的SST-风协变，但单位SST距平引起的风变比赤道以北大得多。在赤道锋较宽的中太平洋，北方SST型具有较大的纬向尺度，最北可达6 ° N。在热带辐合带（ITCZ）以北，局部海温异常较小，云和降水存在显著的变化，这与地面风辐合进一步相关。在大西洋，在SST中的TIW信号被强烈地捕获在赤道附近，但是它们在ITCZ中引起显著的远程响应，ITCZ比太平洋对应物更靠南，因此更容易受到TIW的影响。
A La Nina took place in the equatorial Pacific in 1999, and strong tropical instability waves (TIWs) developed, causing large meanders of a sea surface temperature (SST) front between the equator and 3 degreesN. High-resolution satellite measurements are used to describe the variability of SST, surface wind velocity, column-integrated water vapor, cloud liquid water, and precipitation associated with these strong TIWs in 1999. Coherent ocean-atmosphere patterns emerge in both the Pacific and Atlantic, revealing rich regional characteristics. In the far eastern Pacific, southeasterly trades strengthen (weaken) over positive (negative) SST anomalies, apparently due to enhanced (reduced) mixing with high-speed winds aloft. In the central Pacific we find evidence that SST-induced sea level pressure changes also contribute substantially to wind fluctuations. Similar SST-wind covariability also exists in the Southern Hemisphere along 2 degreesS, but the wind variability induced by unit SST anomaly is much larger than that north of the equator. In the central Pacific where the equatorial front is broad, the northern SST pattern has a large meridional scale and reaches as far north as 6 degreesN. Further to the north in the Intertropical Convergence Zone (ITCZ) where local SST anomalies are small, significant variability is found in clouds and precipitation, which is further correlated with surface wind convergence. In the Atlantic, TIW signals in SST are strongly trapped near the equator, but they induce significant remote response in the ITCZ, which takes a more southern position than its Pacific counterpart and thus more susceptible to TIW influence.