摘要
西伯利亚高压是冬季影响亚洲大陆地区的重要环流因子 ,本文用冬季 (1～ 3月 ) 70°～ 12 0°E ,40°～ 6 0°N区域平均海平面气压值代表其强度 ,分析其变化特征。结果表明 ,从 192 2年到 1970年代中期 ,西伯利亚高压略有增强趋势 ,但并不显著。但近 2 0多年来的显著减弱非常突出。用NCAR资料计算的线性趋势是 - 1.78hPa/ 10a(1976— 2 0 0 0年 ) ,用CRU气压资料计算的趋势是 - 2 .15hPa/ 10a(1976— 1995年 )。西伯利亚高压对中高纬亚洲大陆平均 (30°～ 140°E ,30°～ 70°N)温度和降水都有显著影响 ,与两个要素的相关系数分别达到 - 0 .5 8和 - 0 .44。如果同时考虑其他的影响因子 (如北极涛动、欧亚遥相关型等 ) ,72 %的温度变化及 2 6 %的降水变化能得到解释。其中北极涛动对亚洲大陆的温度贡献最高达到 30 % ,西伯利亚高压的贡献为 2 4%。而区域平均降水变化的 9.
Siberian High is a very important atmospheric circulation system in wintertime (from January to March). It influences the temperature and precipitation in mid-high Asia remarkably. Its variability was investigated for 79 years (from 1922 to 2000). The central pressure intensity which reflects the air mass over the Siberian High center was measured by the mean sea level pressure averaged over 70°～120°E, 40°～60°N. Strong weakening in the central pressure intensity has occurred in recent couples of decades. From 1922 to the middle 1970s, Siberian High intensity showed slight positive trends, but not significant. The striking weakening in recent 20 years are most remarkable. Linear trend for NCAR series is -1.78 hPa/10a from 1976 to 2000, for CRU data sets the trend is -2.15 hPa/10a from 1976 to 1995.There are also very strong coupling between Siberian High and the undersurface climate across Asian continent.Averaged temperature over 30°～140°E and 30°～70°N correlates to Siberian High at -0.58 for 78 winters from 1922 to 1999. For precipitation, the correlation is -0.44 during 1922 to 1998, both statistically significant above 99% confidence level. Siberian High, Arctic Oscillation, Eurasian Pattern and Southern Oscillation together can explain 72% and 26% variance in temperature and precipitation, respectively. The fraction solely related to the Siberian High is 24% and 9.8% in temperature and precipitation
出处
《高原气象》
CSCD
北大核心
2002年第1期8-14,共7页
Plateau Meteorology
基金
国家重点基础研究发展规划首批项目 (G19980 40 90 0 )
国家自然科学基金项目 ( 4 0 10 5 0 0 7)资助
