青海地区冬季气温年际变化及其成因分析
作者简介:王冀(1973-),男,河北武强人,博士,高级工程师,主要从事全球气候变化研究。E-mail: wangji_zl@163.com
收稿日期: 2013-08-25
要求修回日期: 2013-11-20
网络出版日期: 2015-01-15
基金资助
国家科技支撑计划课题(2009BAC51B05)、中国气象局气候变化专项(CCSF2011-15)资助
Interannual Variability and Its Causes of Winter Temperature in Qinghai Region
Received date: 2013-08-25
Request revised date: 2013-11-20
Online published: 2015-01-15
Copyright
王冀 , 申红艳 , 张英娟 , 王振宇 . 青海地区冬季气温年际变化及其成因分析[J]. 地理科学, 2015 , 35(1) : 99 -106 . DOI: 10.13249/j.cnki.sgs.2015.01.99
Interannual variation of temperature in winter over Qinghai and its mechanisms are analyzed using data(1961-2010) from 38 stations over the region as well as National Centers for Environmental Prediction(NCEP) reanalysis data. It unveiled that there exist two major temperature anomaly patterns in winter over Qinghai: unipole mode from north to south and dipole mode between east and west region. During cold winter a “+-+” wave train lay over mid-high latitude with a quasi-barotropic vertical structure. West Pacific index has the most prominent correlation with time coefficient of prime component 1, secondly, the Euro-Asian index and Pacific-North America index. Sea surface temperature anomalies (SSTA) over the south part of North Atlantic in winter may influence atmosphere circulations over Europe and Asian by setting off a Euro-Asian train. Besides, SSTA in both west wind drift and Kuroshio current region have a negative feedback to the East Asian winter monsoon. Also during an El Nino Modoki episode, moist warm air from low latitude transport northward no farther than East China, which make colder winter in Qinghai on account of strong westerly and boreal airflow.
Key words: Qinghai region; winter temperature; teleconnection; Interannual variation
Fig. 1 Distribution of meteorological stations in Qinghai Province图1 青海地区站点分布 |
Fig.2 Spatial patterns of the first two EOF of the DJF mean temperature anomalies in Qinghai Province in 1961-2010图2 1961-2010年青海地区冬季气温EOF分解前2个特征向量的空间模态 |
Fig.3 Correlations between the related time serise coefficients of the first two EOF and the DJF mean anomalies of temperature in 1961-2010图3 EOF前2两个特征向量对应的时间系数与中国160站冬季气温距平的相关系数空间分布(1961-2010年) |
Fig.4 DJF mean differences of the composite geoptential height between high and low temperature years on interannual timescale图4 青海地区冬季气温 EOF第一特征向量所对应的时间系数年际尺度典型低、高温年的位势高度差值场 |
Table 1 The correlation coefficients between the times series of the first modes of the DJF mean temperature anomalies and the indices of Tele-connection patterns表1 EOF 第一模态对应的时间序列与各遥相关指数的相关系数 |
EOF 模态 | 北极涛动 (AO) | 太平洋北美型 (PNA) | 北大西洋涛动 (NAO) | 太平洋西部型 (WP) | 北太平洋涛动 (NPO) | 欧亚遥相关 (EU) |
---|---|---|---|---|---|---|
提前一季 | -0.08 | 0.13 | 0.09 | 0.45 | 0.03 | 0.11 |
同季 | -0.20 | -0.331 | -0.23 | 0.62 | 0.21 | -0.46 |
Fig.5 The simultaneous regression of 500 hPa geopotential height(a), 200 hPa geopotential height(b) on the winter mean EU index图5 冬季EU指数对同期(a)500 hPa、(b)200 hPa 高度场的线性回归 |
Fig.6 The simultaneous regression of 500 hPa geopotential height(a), 700 hPa wind vector field(b) on the winter mean WP index图6 冬季太平洋西部型指数对同期500 hPa高度场(a)及700 hPa风场线性回归(b) |
Table 2 The correlation coefficients between the series in typical years about first modes and the index in Nino3, Nino4 region表2 EOF第一模态对应的年际尺度典型年份时间序列与Nino3、Nino4指数相关系数 |
Nino指数 | (0) | (-1) | (-2) | (-3) |
---|---|---|---|---|
Nino3 | 0.17 | 0.05 | 0.16 | 0.07 |
Nino4 | 0.21 | 0.13 | 0.16 | 0.17 |
注:(0)表示同期相关;(-1)表示提前一季;(-2)表示提前两季;(-3)表示提前三季 |
Fig.7 The correlation coefficients between the time series of coefficient of first EOF of the winter temperature and SST of the North Atlantic(a, autumn; b, winter) and SST of the North Pacific (c, autumn; d, winter)图7 青海冬季气温EOF第一模态时间系数与北大西洋(a.秋季; b.冬季)和北太平洋海温(c.秋季; d.冬季)相关分布 |
Fig.8 DJF mean differences of the composite 850 hPa wind vector field(a) and anomaly(b)in center El-Nino years图8 中部型EL-Nino年850 hPa风场合成(a)和距平(b) |
The authors have declared that no competing interests exist.
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