When the waves meet the western boundary, they are reflected, and the model predicts that Rossby waves will be broken into numerous coastal Kelvin waves carrying the same negative sea-level signal. These eventually shoot toward the equator, and then head eastward along the equator propelled by the rotation of the Earth at a speed of about 250 kilometers per day. When enough Kelvin waves of sufficient amplitude arrive from the western Pacific, their negative sea-level signal overcomes the feedback mechanism tending to raise the sea level, and they begin to drive the system into the opposite cold mode. This produces a gradual shift in winds, one that will eventually send positive sea-level Rossby waves westward, waves that will eventually return as cold cycle-ending positive Kelvin waves, beginning another warming cycle.
数学模型最近对厄尔尼诺的出现所作出的显然是成功的预测使研究者们兴奋不已。所谓厄尔尼诺,即一股沿南美洲太平洋海岸周期性发展的海洋暖流。早在20年之前,雅各皮叶克尼斯指出了风何以可能在东部赤道太平洋地区形成反常温暖或反常寒冷的水域。虽然如此,在上述数学模型得以发展之前,还没有任何人能够解释情况为什么应该有规律地从一种转变为另一种,正如在暖厄尔尼诺和冷厄尔尼诺出现之间周期性的交替变化中所发生的那样。问题的答案至少如果目前将海洋的行为与大气层的行为联系起来的模型是正确的话应从海洋中寻找。
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