韵律与长期天气预报

RHYTHM AND LONG-RANGE WEATHER FORECASTING

中文摘要:

      本文讨论了对长期天气预报比较重要的韵律问题,共有三部分内容:(1)分析广大台站在相关普查中发现的隔季相关现象,相关间隔自2个月到11个月不等,其中大约半年左右的比较常见,并且地理分布区域性强,大洋上最明显,指出这是韵律现象.(2)月平均环流与海温的相似性分析表明,北半球环流与海温都存在着隔季相似性.例如,春或夏海温距平相似时,大约6个月之后又相似.而秋冬春三季大气环流的相似容易造成夏季大气环流的相似.指出这是大气环流与海洋的韵律活动的表现.(3)讨论了两种可能的韵律形成过程,一种是北太平洋西风漂流区夏季海温通过韵律关系影响半年后的冬季海温,从而影响大气环流和天气.另一种是冬季低纬东太平洋海温与大气环流相互作用,通过韵律关系影响半年之后夏季低纬太平洋的环流,从而影响西太平洋副高及我国天气.

英文摘要:

      Many papers show that the rhytms take an important part in long-range weather forecasting. The rhythms appear in wide band of spectrum varying, from two months to eleven months, but the most dominant is the half year rhythm. Investigations on the development of similarities between two monthly mean circulation maps in the Northern Hemisphere or between two sea surface temperature maps in North Pacific and North Atlantic proved the realities of the rhythm activities. For example, if the sea surface temperature anomalies are similar for two months in spring or summer, then they usually get some similarity in both following autumn or winter. Atmospheric circulation anomalies in summer are formed under the influence of atmospheric circulation anomalies in the past three and four seasons. Two kinds of mechanism controlling rhythms were proposed. The first, summer sea surface temperature in the westerly drift current in the North Pacific can give some influence on the winter sea surface temperature, and then on the atmospheric circulation and weather. The second, both sea surface temperature and atmospheric circulation in the low latitudes at east part of North Pacific in winter act as forcing factors to the atmospheric circulation in the following summer.