Dynamics of Low Frequency Phenomena

该项目将调查热带大气和海洋的低频变化。研究活动分为三大领域。第一，伴随亚洲季风的季节内变化的可预测性。早期的工作表明，季风降雨的变化可能会在南亚造成严重的洪灾和重大的农业影响，这一变化是可以预测的，这项赠款下的工作将构建和测试这种季节内变化的预报方法。第二，决定西太平洋暖池大小的热力学和动力过程，西太平洋暖池是太平洋海表温度最高的区域，以大尺度大气对流和降水为特征。在过去的30年里，暖池的面积急剧增加，而大范围对流的面积却保持不变。在这里开展的工作试图确定控制暖池和对流区大小的因素，并确定它们的年际变化和长期变化。第三，亚洲季风年际变化的基本动力。这项工作将侧重于印度多年季风降雨量极度不足和极端过剩的可能性。这项工作的更广泛影响超出了了解热带气候动力学的科学目标，因为季风降雨量的波动对南亚和东南亚的人口造成了严重影响。这项研究的重点是开发预测方法，这可能具有相当大的实用价值。此外，研究基金将为两名研究生和两名博士后学者提供培训、教育和支持。

This project will investigate the low-frequency variability of the tropical atmosphere and oceans. Research activities fall into three broad areas. First, predictability of intraseasonal variability accompanying the Asian monsoon. Earlier work suggests variations in monsoon rainfall which can cause severe flooding and substantial agricultural impacts in South Asia may be predictable, and work under this grant will construct and test forecasting methods for this intraseasonal variability. Second, the thermodynamic and dynamic processes which determine the size of the western Pacific warm pool, the region of largest sea surface temperature (SST) in the Pacific ocean, which is characterized by large-scale atmospheric convection and precipitation. The area of the warm pool has increased dramatically over the last 30 years, yet the area of large-scale convection has remained constant. Work conducted here seeks to determine the factors which control the size of the warm pool and convecting region and determine their year-to-year variability and long-term secular change. Third, the underlying dynamics of the year-to-year variability of the Asian monsoon. The work will focus on the possibility that years of extremely deficient and extremely excessive monsoon rainfall in India may be predictable.The broader impacts of the work go beyond the scientific goals of understanding tropical climate dynamics, since fluctuations in monsoon rainfall have severe effects on the populations of South and Southeast Asia. The research has a strong emphasis on developing forecast methodologies which could be of considerable practical value. In addition, research funds will provide training, education, and support for two graduate students and two postdoctoral scholars.