The impact of the Northeast Cold Vortex on early summer precipitation anomalies in the Haihe River Basin
-
摘要:
东北冷涡是东亚中高纬度地区的重要天气系统，其频繁活动可能导致显著的气候效应，不仅对东北局地，而且对海河流域地区初夏降水产生影响.本文利用海河流域34个地面气象台站逐日降水资料以及NCEP/NCAR再分析资料，对东北冷涡与海河流域初夏降水的关系进行研究，结果表明：初夏东北冷涡活动与海河流域降水存在显著的相关关系，对其空间分布亦有重要影响.当东北冷涡活动偏多（少）时，海河流域北部地区（尤其是海河下游）初夏降水可能偏多（少），对应时间系数为正（负）时海河流域初夏降水EOF第二模态北多（少）南少（多）的空间分布.在东北冷涡活动偏多年，东北冷涡引导北方"干冷"空气南下推进至海河流域北部，伴随该地区源自西风带水汽输送和水汽辐合的增强，形成了"上干下湿"的不稳定层结，在上升运动的触发下，导致海河流域北部初夏降水偏多；而东北冷涡活动偏少年情况正好相反.东北冷涡活动为海河流域尤其是海河下游地区初夏降水预测提供了具有参考意义的结果，其活动指数与海河下游初夏降水距平的符号一致率在近30年高达83%.
Abstract:The Northeast Cold Vortex (NECV) is a major synoptic system at the mid and high latitudes of East Asia, of which the frequent activities may lead to significant impact on climate change, not just in Northeast China, but in the Haihe River Basin (HRB). In this paper, an objective index of the NECV (NECVI) is defined, and then a significant correlation between the activities of the NECV and precipitation in the HRB is investigated during early summer, by using daily precipitation data of 34 meteorological stations over the HRB and NCEP/NCAR reanalysis data. Results show that frequent (infrequent) activities of the NECV are related to more (less) precipitation in the northern basin, corresponding to the spatial characteristic of precipitation in the HRB, with more (less) in north and less (more) in south, when the second EOF mode time coefficient is positive (negative). During early summer, the frequent activities of the NECV are often related to the cold air moving southward, the intensive moisture convergence, the unstable stratification occurring and strong ascending movements developing in the low troposphere in the northern basin, which offer necessary atmospheric circulation conditions for increasing of precipitation, and vice versa. The symbol consistency in recent three decades between the NECVI and precipitation anomalies in the lower reaches of the HRB is up to 83%. In conclusion, a reference is offered for precipitation prediction in the HRB, especially the lower reaches during early summer.
-
-
图 1
1961—2010年逐年初夏(6月，下同)东北冷涡500 hPa位势高度低压中心在115°E—125°E区域的最南位置
Figure 1.
Southernmost locations of the low pressure center at 500 hPa during the NECV (Northeast Cold Vortex) events over 115°E—125°E in annual early summer (June, the same below) from 1961 to 2010
图 2
(a) 1961—2010年初夏NECVI指数(标准化东北冷涡活动指数，下同)与海河流域降水的相关分布(圆圈表示海河流域34个台站分布；阴影表示置信度水平达到95%的区域)；(b) 1961—2010年海河流域初夏降水量场EOF第二模态空间分布型
Figure 2.
(a) Distribution of correlation coefficients between the NECVI (Northeast Cold Vortex Index, the same below) and precipitation in the Haihe River Basin during early summer from 1961 to 2010. The circles indicate distribution of 34 stations in the Haihe River Basin. Shaded areas denote the values exceeding 95% confidence level. (b) The second empirical orthogonal function (EOF) spatial mode of precipitation in the Haihe River Basin during early summer from 1961 to 2010
图 3
1961—2010年初夏NECVI指数和海河流域降水指数HRBPI时间序列(a)与海河流域初夏降水量场EOF第二模态标准化时间系数(b)的对应关系
Figure 3.
Standardized time series of the NECVI and the HRBPI (Haihe River Basin Precipitation Index) (a) and time coefficient of the second EOF mode of precipitation in the Haihe River Basin (b) during early summer from 1961 to 2010
图 4
1961—2010年初夏NECVI指数与天津地区平均降水量的15年滑动相关系数(曲线)
Figure 4.
15-year sliding correlation coefficients (curve) between the NECVI and average precipitation in Tianjin during early summer from 1961 to 2010
图 5
200 hPa(a)、500 hPa(b)和850 hPa(c)位势高度场在初夏东北冷涡活动异常偏多和偏少年的合成差异(单位：gpm)
Figure 5.
Composite differences in geopotential height at 200 hPa (a), 500 hPa (b), and 850 hPa (c) pressure levels between more and less cold vortex years chosen by early summer over Northeast China (unit: gpm)
图 7
850 hPa水平风场(a，单位：m·s-1)和整层水汽输送(矢量，单位：kg·m-1·s-1)及其散度(等值线，单位：10-6kg·m-2·s-1)(b)在初夏东北冷涡活动异常偏多和偏少年的合成差异
Figure 7.
Composite differences in 850 hPa winds (a) (unit: m·s-1) and the whole layer water vapor transportation (vector, unit: kg·m-1·s-1) and its divergence (contour, unit: 10-6kg·m-2·s-1) (b) between more and less cold vortex years chosen by early summer over Northeast China
图 6
850 hPa温度场在初夏东北冷涡活动异常偏多和偏少年的合成差异(单位：℃)
Figure 6.
Composite difference in 850 hPa temperature field between more and less cold vortex years chosen by early summer over Northeast China (unit: ℃)
图 8
850 hPa(a)和300 hPa(b)相对湿度场在初夏东北冷涡活动异常偏多和偏少年的合成差异(单位：%)
Figure 8.
Composite differences in relative humidity at 850 hPa (a) and 300 hPa (b) pressure levels between more and less cold vortex years chosen by early summer over Northeast China (unit: %)
-
Duan C F. 2012. Climate characteristics, effects and its influencing factors of cold vortex over Northeast China[Ph. D. thesis] (in Chinese). Nanjing:Nanjing University of Information Science and Technology.
Duan L Y, Rong Y S, Liang P D. 2008. Effect of west pacific subtropical high on summer precipitation in North China. Meteorological Science and Technology (in Chinese), 36(3):273-276. http://www.en.cnki.com.cn/Article_en/CJFDTOTAL-QXKJ200803004.htm
He J H, Wu Z W, Jiang Z H, et al. 2006a. "Climate effect" of the northeast cold vortex and its influences on Meiyu. Chinese Science Bulletin, 52(5):671-679. http://d.wanfangdata.com.cn/Periodical/kxtb-e200705015
He J H, Wu Z W, Qi L, et al. 2006b. Relationships among the Northern Hemisphere annual mode, the northeast cold vortex and the summer rainfall in Northern China. Journal of Meteorology and Environment (in Chinese), 22(1):1-5. http://en.cnki.com.cn/Article_en/CJFDTOTAL-LNQX200601000.htm
Hu K X, Lu R Y, Wang D H. 2011. Cold vortex over Northeast China and its climate effect. Chinese Journal of Atmospheric Sciences (in Chinese), 35(1):179-191. http://en.cnki.com.cn/Article_en/CJFDTotal-DQXK201101016.htm
Ju J H, Lu J M, Cao J, et al. 2005. Possible impacts of the Arctic Oscillation on the interdecadal variation of summer monsoon rainfall in East Asia. Advances in Atmospheric Sciences, 22(1):39-48. doi: 10.1007/BF02930868
Kalnay E, Kanamitsu M, Kistler R, et al. 1996. The NCEP/NCAR 40-year reanalysis project. Bulletin of the American Meteorological Society, 77(3):437-471. doi: 10.1175/1520-0477(1996)077<0437:TNYRP>2.0.CO;2
Li J P, Wang J X L. 2003. A modified zonal index and its physical sense. Geophysical Research Letters, 30(12):1632, doi:10.1029/2003GL017441.
Liang P, He J H, Chen L X, et al. 2007. Anomalous moisture sources for the severe precipitation over North China during summer. Plateau Meteorology (in Chinese), 26(3):460-465. http://en.cnki.com.cn/Article_en/CJFDTOTAL-GYQX200703003.htm
Miao C S, Wu Z W, He J H, et al. 2006. The anomalous features of the Northeast cold vortex during the first flood period in the last 50 years and its correlation with rainfall in South China. Chinese Journal of Atmospheric Sciences (in Chinese), 30(6):1249-1256. http://www.oalib.com/paper/1556351
Simmonds I, Bi D H, Hope P. 1999. Atmospheric water vapor flux and its association with rainfall over China in summer. Journal of Climate, 12(5):1353-1367. doi: 10.1175/1520-0442(1999)012<1353:AWVFAI>2.0.CO;2
Sun L, Zheng X Y, Wang Q. 1994. The climatological characteristics of Northeast cold vortex in China. Quarterly Journal of Applied Meteorology (in Chinese), 5(3):297-303. http://en.cnki.com.cn/Article_en/CJFDTOTAL-YYQX403.005.htm
Sun L, An G, Lian Y, et al. 2000. A study of the persistent activity of northeast cold vortex in summer and its general circulation anomaly characteristics. Acta Meteorological Sinica (in Chinese), 58(6):704-714. http://www.cmsjournal.net/qxxben/ch/reader/view_abstract.aspx?file_no=20000606&flag=1
Tian H, Guo P W, Lu W S. 2002. Features of water vapor transfer by summer monsoon and their relations to rainfall anomalies over China. Journal of Nanjing Institute of Meteorology (in Chinese), 25(4):496-502. http://en.cnki.com.cn/Article_en/CJFDTotal-NJQX200204008.htm
Zhai Y J, Li Y H, Shi C H. 2013. Temporal and spatial characteristics of August precipitation in North China and its causes in last 50 years. Plateau Meteorology (in Chinese), 32(3):787-797, doi:10.7522/j.issn.1000-0534.2012.00073.
Zhang Q Y, Tao S Y. 1998. Influence of Asian mid-high latitude circulation on East Asian summer rainfall. Acta Meteorologica Sinica (in Chinese), 56(2):199-211. http://en.cnki.com.cn/article_en/cjfdtotal-qxxb802.006.htm
Zhang Q Y, Tao S Y, Zhang S L. 2001. A study of excessively heavy rainfall in the Songhuajiang-Nenjiang River Valley in 1998. Chinese Journal of Atmospheric Sciences (in Chinese), 25(4):567-576. http://en.cnki.com.cn/Article_en/CJFDTOTAL-DQXK200104012.htm
Zhao S X, Sun J H. 2007. Study on cut-off low-pressure systems with floods over Northeast Asia. Meteorology and Atmospheric Physics, 96(1-2):159-180. doi: 10.1007/s00703-006-0226-3
Zhou X X, Ding Y H, Wang P X. 2008. Features of moisture transport associated with the precipitation over North China during July-August. Chinese Journal of Atmospheric Sciences (in Chinese), 32(2):345-357. http://en.cnki.com.cn/Article_en/CJFDTOTAL-DQXK200802012.htm
段春峰. 2012. 东北冷涡的气候学特征、效应及其影响因素[博士论文]. 南京: 南京信息工程大学.
段丽瑶, 荣艳淑, 梁平德. 2008.西太平洋副热带高压位置对华北盛夏降水的影响.气象科技, 36(3):273-276. http://www.cnki.com.cn/Article/CJFDTOTAL-QXKJ200803004.htm
何金海, 吴志伟, 江志红等. 2006a.东北冷涡的"气候效应"及其对梅雨的影响.科学通报, 51(23):2803-2809. http://www.cnki.com.cn/Article/CJFDTOTAL-KXTB200623016.htm
何金海, 吴志伟, 祁莉等. 2006b.北半球环状模和东北冷涡与我国东北夏季降水关系分析.气象与环境学报, 22(1):1-5. http://www.cnki.com.cn/Article/CJFDTOTAL-LNQX200601000.htm
胡开喜, 陆日宇, 王东海. 2011.东北冷涡及其气候影响.大气科学, 35(1):179-191. http://www.cnki.com.cn/Article/CJFDTOTAL-DQXK201101016.htm
梁萍, 何金海, 陈隆勋等. 2007.华北夏季强降水的水汽来源.高原气象, 26(3):460-465. http://www.cnki.com.cn/Article/CJFDTOTAL-GYQX200703003.htm
苗春生, 吴志伟, 何金海等. 2006.近50年东北冷涡异常特征及其与前汛期华南降水的关系分析.大气科学, 30(6):1249-1256. http://www.cnki.com.cn/Article/CJFDTOTAL-DQXK200606018.htm
孙力, 郑秀雅, 王琪. 1994.东北冷涡的时空分布特征及其与东亚大型环流系统之间的关系.应用气象学报, 5(3):297-303. http://www.cnki.com.cn/Article/CJFDTOTAL-YYQX403.005.htm
孙力, 安刚, 廉毅等. 2000.夏季东北冷涡持续性活动及其大气环流异常特征的分析.气象学报, 58(6):704-714. doi: 10.11676/qxxb2000.071
田红, 郭品文, 陆维松. 2002.夏季水汽输送特征及其与中国降水异常的关系.南京气象学院学报, 25(4):496-502. http://www.cnki.com.cn/Article/CJFDTOTAL-NJQX200204008.htm
翟颖佳, 李耀辉, 施春华. 2013.近50年华北区8月降水异常的时空特征及其成因分析.高原气象, 32(3):787-797, doi:10.7522/j.issn.1000-0534.2012.00073.
张庆云, 陶诗言. 1998.亚洲中高纬度环流对东亚夏季降水的影响.气象学报, 56(2):199-211. doi: 10.11676/qxxb1998.019
张庆云, 陶诗言, 张顺利. 2001. 1998年嫩江、松花江流域持续性暴雨的环流条件.大气科学, 25(4):567-576. http://www.cnki.com.cn/Article/CJFDTOTAL-DQXK200104012.htm
周晓霞, 丁一汇, 王盘兴. 2008.影响华北汛期降水的水汽输送过程.大气科学, 32(2):345-357. http://www.cnki.com.cn/Article/CJFDTOTAL-DQXK200802012.htm
-
下载:
图(9)
计量
- 文章访问数: 1816
- PDF下载数: 471
- 施引文献: 0