来自大气内部的季节气候可预测性初探

这是一个十分初步的工作结果.通常认为,气候的季节-年际可预测性主要来自缓慢变化的大气外强迫的异常(如海表温度、积雪、土壤温度和湿度等).作者从大气月平均风场异常的持续性以及与东亚季风年际异常相关的全球大气环流异常特征两个方面初步探讨东亚夏季气候的可预测性.初步结果说明,大气月平均风场在对流层上层和平流层下层的热带区域及一些关键区域可持续性可以超过一个季节,并且与东亚季风有显著相关,从而使得从大气内部变化来考虑东亚夏季风气候仍然有一定的可预测性.

Preliminary Research on the Inner-Atmosphere-Originated Seasonal Climate Predictability

This is a very preliminary work on detection of seasonal climate predictability arising from the internal atmosphere. Generally speaking, seasonal climate predictability is mostly determined by the external forcing that has larger scale of temporal variation, namely, the sea surface temperature, snow cover, soil wetness, and so on. Based on analyzing the persistence of monthly mean wind anomalies and the East Asian monsoon-related global-scale atmospheric circulation anomalies, the inner-atmosphere-originated seasonal climate predictability is discussed. The results show that the wind anomalies in spring in many key regions like upper troposphere and lower stratosphere in the tropics, which is closely related to the East Asian monsoon, may persist for up to 4 to 5 months. Thus, climate predictability may be partly originated by the internal processes of the atmosphere.