Based on the ERA40 reanalysis dataset and the observed precipitation data from Chinese stations, two major modes of wintertime westerly from Northern Atlantic to the upstream region of Qinghai-Xizang Plateau (QXP) were investigated through empirical orthogonal function (EOF) and their connections with the wintertime regional precipitation of China and the Northern Atlantic Oscillation (NAO). It reveals that the associated time series of the first two major modes of wintertime westerly (EOF1 and EOF2) over the upstream area of QXP are significantly correlated with the NAO, while their connections with the regional wintertime precipitation of China are totally different. The EOF1 is evidently correlated with the precipitation over the south-west of the QXP as well as the precipitation over the middle and lower reaches of Yangtze River. However, the EOF2 delineates no significant correlation with the wintertime precipitation over China. Further analysis suggests that the anomalous westerly in the low altitudes associated with EOF1 can reach to the upstream of QXP in the mid-south Asia-Europe continent, increases the creeping flow over the south-west of the QXP, enhances the precipitation over the south-west of the QXP, and vice versa. Due to the topography blocking, the detouring flow around the south side of QXP becomes stronger, converges with the anomalous south-easterly from the south side of anomalous west-Pacific subtropical high over the middle-lower reaches of Yangtze River, enhances the ascending movement, increases the anomalous precipitation over the middle and lower reaches of Yangtze River, and vice versa. While, the relationship between the EOF2 and the wintertime precipitation over China is not significant due to the anomalous zonal wind component in the low latitudes associated with EOF2 does not extend eastward. From this study, the extension of the westerly over the upstream region of QXP plays an important role in affecting the wintertime precipitation over China, and the westerly wave train associated with EOF1 in westerly is an important medium for NAO to influence the wintertime precipitation over China.
YU Jingjing
,
LIU Yimin
,
LI Xiaofeng
. Connections between the Dominant Modes of Westerly over the Upstream Region of Qinghai-Xizang Plateau and the Regional Precipitation of China and NAO in Winter[J]. Plateau Meteorology, 2014
, 33(4)
: 877
-886
.
DOI: 10.7522/j.issn.1000-0534.2013.00108
[1]陶诗言, 卫捷. 2008年1月我国南方严重冰雪灾害过程分析[J]. 气候与环境研究, 2008, 13(4): 337-350.
[2]张自银, 龚道溢, 郭栋, 等. 我国南方冬季异常低温和异常降水事件分析[J]. 地理学报, 2008, 63(9): 899-912.
[3]王林, 冯娟. 我国冬季降水年际变化的主模态分析[J]. 大气科学, 2011, 35(6):1105-1116.
[4]许立言, 武炳义. 欧亚大陆积雪与2010年中国春末夏初降水的关系[J]. 高原气象, 2012, 31(3): 706-714.
[5]何溪澄, 丁一汇, 何金海, 等. 中国南方地区冬季风降水异常的分析[J]. 气象学报, 2006, 64(5): 594-604.
[6]钱卓蕾. 长江中下游冬季降水特征和影响因素分析[J]. 高原气象, 2013, 32(6): 1795-1802, doi: 10.7522/j.issn.1000-0534.2012.00166.
[7]曾剑, 张强, 王同美. 东亚冬季风与中国南方冬季降水的关系分析[J]. 高原气象, 2010, 29(4): 975-981.
[8]帅嘉冰, 郭品文, 庞子琴.中国冬季降水与AO关系的年代际变化[J]. 高原气象, 2010, 29(5): 1126-1136.
[9]丁一汇. 东亚冬季风的统计研究[J]. 热带气象学报, 1990, 6(2): 119-128.
[10]陈隆勋, 朱乾根, 罗汇邦. 东亚季风[M]. 北京: 气象出版社, 1991:62-67.
[11]黄荣辉, 顾雷, 陈际龙, 等. 东亚季风系统的时空变化及其对我国气候异常影响的最近研究进展[J]. 大气科学, 2008, 32(4): 691-719.
[12]龚道溢, 朱锦红, 王绍武. 西伯利亚高压对亚洲大陆的气候影响分析[J]. 高原气象, 2002, 21(1): 8-14.
[13]Thompson D W J, Wallace J M. The Arctic Oscillation signature in the wintertime geopotential height and temperature fields[J]. Geophys Res Lett, 1998, 25(9): 1297-1300.
[14]Thompson D W J, Wallace J M. Annular modes in the extratropical circulation. Part I: Month-to-month variability[J]. J Climate, 2000, 13(5): 1000-1016.
[15]Kerr R A. Getting a handle on the Norths El Nio[J]. Science, 2001, 294(5542): 494-495.
[16]段安民, 吴国雄. 青藏高原气温的年际变率与大气环状波动模[J]. 气象学报, 2005, 63(5):790-798.
[17]龚道溢, 王绍武. 近百年北极涛动对中国冬季气候的影响[J]. 地理学报, 2003, 58(4): 559-568.
[18]李建平. 北极涛动的物理意义及其与东亚大气环流的关系[M]//俞永强, 陈文. 海-气相互作用对我国气候变化的影响. 北京: 气象出版社, 2005:169-176.
[19]Li J, Yu R C, Zhou T J, et al. Why is there an early spring cooling shift downstream of the Tibetan Plateau?[J]. J Climate, 2005, 18(22): 4660-4668.
[20]Li J, Yu R C, Zhou T J. Teleconnection between NAO and climate downstream of the Tibetan Plateau[J]. J Climate, 2008, 21(18): 4680-4690.
[21]王林, 冯娟. 我国冬季降水年际变化的主模态分析[J]. 大气科学, 2011, 35(6): 1105-1116.
[22]宇婧婧, 刘屹岷, 吴国雄. 冬季青藏高原大气热状况分析Ⅰ:气候平均[J]. 气象学报, 2011, 69(1): 79-88.
[23]宇婧婧, 刘屹岷, 吴国雄. 冬季青藏高原大气热状况分析Ⅱ:年际变化[J]. 气象学报, 2011, 69(1): 89-98.
[24]North G R, Bell T L, Cahalan R F, et al. Sampling errors in the estimation of empirical orthogonal functions[J]. Mon Wea Rev, 1982, 110(7): 699-706.
[25]李崇银, 李桂龙. 北大西洋涛动和北太平洋涛动的演变与20世纪60年代的气候突变[J]. 科学通报, 1999, 44(16): 1765-1769.
[26]Yeh T C. On the formation of quasi-geostraphic motion in the atmosphere[J]. J Meteor Soc Japan. The 75\+th Anniversary Volume of the Meteorological Society of Japan, 1957: 130-134.
[27]曾庆存. 初始扰动结构对适应过程的影响及观测风场的应用[J]. 气象学报, 1963, 33(1): 37-50.
[28]Barnston A G, Livezey R E. Classification, seasonality and persistence of low-frequency atmospheric circulation patterns[J]. Mon Wea Rev, 1987, 115(6):1083-1126.
[29]Rogers J C. Patterns of low-frequency monthly sea level pressure variability (1899-1986) and associated wave cyclone frequencies[J]. J Climate, 1990, 3(12):1364-1379.
[30]Hurrell J W, Van Loon H. Decadal variations in climate associated with the North Atlantic Oscillation[J]. Climatic Change, 1997, 36(3):301-326.
[31]Jung T, Hilmer M, Ruprecht E, et al. Characteristics of the recent eastward shift of interannual NAO variability[J]. J Climate, 2003, 16(20): 3371-3382.
