北半球冬季大气活动中心的基本态特征及影响研究  

STUDY OF NORTHERN WINTER ATMOSPHERIC ACTIVE CENTERS(AAC) CLIMATE BASE-STATE WITH ITS CLIMATE VARIABILITY AND EFFECTS

作　　者：施能[1] 陈辉[1] 谌芸[1] 

机构地区：[1]南京气象学院,江苏南京210044

出　　处：《热带气象学报》2001年第3期215-222,共8页Journal of Tropical Meteorology

基　　金：国家自然科学基金(No:49875019)资助

摘　　要：通过研究近100多年北半球全部大气活动中心30年以上的慢变平均值(气候基本态)、气候变率特征及时间演变规律,指出阿留申低压与冰岛低压的基本态改变最大。基本态变化最小的是北太平洋高压,其次是北美高压。基本态的变化表现为两个基本模态:第一模态为弱(强)的NA0,较弱(强)的NPO,强(弱)的西伯利亚高压和较弱(强)的阿留申低压的特征;第二模态主要表现为弱(强)的阿留申低压及弱(强)的西伯利亚高压的特征。近期北半球环流基本态是处于第一模态明显的负位相,第二模态明显的正位相下,即特别弱的西伯利亚高压、特别强的阿留申低压及强NA0的慢变环流背景下。这种慢变的环流背景场还可能维持30年左右。所以北半球冬季今后还将长期处于气候暖背景下。Study is undertaken of > 30 year slowly-varying means, called climate base state (CBS), of northern winter AAC's in the past 100 years and more, with the CBS variability and its temporal evolution investigated, indicating that Aleutian low and Icelandic low (North Pacific high and North American high) experience maximum (minimum) variation in the CBS. The CBS exhibits two modes for its variation. The positive (negative) phase of mode I presents a weak (strong) NAO, a weaker (stronger) NPO, a robust (feeble) Siberian high and a quite weak (vigorous) Aleutian low whilst the positive (negative) phase of mode II reveals a feeble (strong) Aleutian low and a weak (robust) Siberian high. Also, the research shows that the recent CBS of northern circulations is in a remarkably negative phase of mode I and a noticeably positive phase of mode II, viz., in the background of slowly-varying circulations of an exceptionally weak Siberian high, an extremely vigorous Aleutian low and an intense NAO. The background field is likely to persist for a matter of 30 years such that northern winter temperature is expected to be in such a warm situation for a long period to follow.

关 键 词：大气活动中心 气候基本态 气候变革 北半球 冬季 长期变化 

分 类 号：P467[天文地球—大气科学及气象学]