Vol.18, NO.3, 2007
Turn off MathJax
Article Contents
Article Navigation >  Journal of Applied Meteorological Science  > 2007  >  18(3): 340-349
Yan Hongming, Wang Ling, Zhou Guolian, et al. The relationship between rainfall in Yunnan summer and the circulation in preceding winter. J Appl Meteor Sci, 2007, 18(3): 340-349.
Citation: Yan Hongming, Wang Ling, Zhou Guolian, et al. The relationship between rainfall in Yunnan summer and the circulation in preceding winter. J Appl Meteor Sci, 2007, 18(3): 340-349.
shu

The Relationship Between Rainfall in Yunnan Summer and the Circulation in Preceding Winter

  • 1.

    Climate Center of Yunnan Province, Kunming 650034

  • 2.

    Yunnan Provincial Meteorological Bureau, Kunming 650034

  • Received Date: 2005-12-28
  • Rev Recd Date: 2006-12-29
  • Publish Date: 2007-06-30
    Abstract
  • At present, in view of the limitation of the understanding of the atmospheric movement, the climate change projection depending completely on general circulation model (GCM) is in an immature period, and relying on the anomalous characteristic of early general circulation is still one of the main methods, particularly in provincial and regional meteorological observatory. So investigating on the prediction clue from early circulation anomalies is very important work, which may provides some scientific evidences to accurately predict the following climate anomalies. A lot of previous researches show the close inter-season linkage between early wintertime circulation and the following summer climate anomalies, the precipitation variations in different regions are not only the significant difference, but also the relationships between them, and early circulation anomalies are distinctly different which needs to be further investigated. Yunnan Province is located in Asian monsoon region and is commonly affected by East Asian monsoon and South Asian monsoon. Its climate anomaly is very complicated and different from those in other regions. Further study on the relationship between early circulation anomalies and Yunnan summer precipitation will be beneficial to improving the forecast accuracy and providing the accurate weather information for government's decision-making to prevent and mitigate the damages resulting from disastrous weather. Based on the monthly NCEP/NCAR reanalysis dataset from 1948 to 2004, 124 stations rainfall from 1961 to 2004 and sea surface temperature of the UK Hadley Center from 1948 to 2003, the temporal and spatial variation features of Yunnan summer (JJA) precipitation are firstly analyzed by using EOF and Morlet wavelet analysis method. Secondly, the relationship between the rainfall and preceding general circulation, air temperature is further investigated by using correlation and composite analysis methods. Yunnan summer precipitation in different regions trends to have the similar variation, and has a significant inter-annual variability and period circle feature with 2 and 4 years. The circulation anomalies in mid-high latitude region of Eastern Asia and atmospheric thermal situation from low-high layer in tropical India Ocean and Pacific Ocean in preceding December and January, particularly in January are significant signals indicating the following climate variation of Yunnan. The rainfall increases when East Asian trough deepens and East Asian winter monsoon (EAWM) strengthens, air temperature from low-high layer is cold. The opposite situation occurs when early East Asian trough weakens, EAWM weakens, and air temperature from low-high layer is warm. Furthermore, the anomalous characteristics of SST in tropical Ocean and its possible effect on the linkage relationship between East Asian winter monsoon and summer monsoon are also investigated. The results show that SSTA in tropical Indian Ocean and western Pacific Ocean keep unchanged from winter to summer, which will impact possibly EASM and rainfall in Yunnan summer by changing land-sea thermal contrast.
    • FullText(HTML)
    References(8)

  • Fig. 1  The first (a) and second (b) empirical orthogonal function (EOF) modes of 124 stations precipitation of Yunnan in JJA during 1961—2004

    DownLoad: Full-Size Img PowerPoint

    Fig. 2  The first principal component time coefficient anomaly of 124 stations precipitation of Yunnan in JJA during 1961—2004 (a) with its Morlet wavelet analysis (b)

    (the area encircled by thick solid line denotes that the period is over 95% level)

    DownLoad: Full-Size Img PowerPoint

    Fig. 3  Difference of anomalous monthly 500 hPa geopotential height from preceding October to succedent May in anomalous Yunnan summer rainfall years (isolines, unit: gpm) with t-test (shaded areas)

    DownLoad: Full-Size Img PowerPoint

    Fig. 4  Correlations between Yunnan summer rainfall and meridional wind (a), zonal wind (b) in preceding January for 1961—2001

    (shaded areas indicate changes at the 95% confindence level)

    DownLoad: Full-Size Img PowerPoint

    Fig. 5  Meridional section along 135°—145°E average (a, b) and zonal section along 10°—25°N average (c, d) stream anomaly in preceding January in anomalous Yunnan summer rainfall years

    (solid and dashed lines denote meridional and zonal wind; light shaded areas denote ascending flow with velocity above 0.005 Pa·s-1 and dark shaded areas denote descending flow with velocity below-0.005 Pa·s-1; arrow heads denote meridional and zonal wind anomaly)

    DownLoad: Full-Size Img PowerPoint

    Fig. 6  Difference of surface temperature anomalies and its t-test (shaded areas) in preceding December (a) and January (b), correlation between Yunnan summer rainfall and surface temperature in preceding December (c) and January (d)

    (shaded areas denote exceeding the test of 95% level)

    DownLoad: Full-Size Img PowerPoint

    Fig. 7  Zonal section of 20°S—20°N temperature average in January of positive rainfall anomaly (a) and negative rainfall anomaly (b)

    DownLoad: Full-Size Img PowerPoint

    Fig. 8  Composites of anomalous wind (unit: m/s) at 850 hPa (a) positive rainfall anomaly, (b) negative rainfall anomaly (shaded areas are exceeding 95%, 98% and 99% level, respectively)

    DownLoad: Full-Size Img PowerPoint

    Fig. 9  Regional averaged SSTA from January to August in equatorial east India ocean (10°S—10°N, 80°—110°E)(a), equatorial west India ocean (10°S—10°N, 40°—80°E)(b), northwest Pacific ocean (10°—30°N, 120°—150°E)(c), and equatorial east Pacific ocean (5°S—5°N, 90°—150°W)(d)

    DownLoad: Full-Size Img PowerPoint
  • [1]
    孙淑清, 孙柏民.东亚冬季风环流异常与我国江淮流域夏季旱涝天气的关系.气象学报, 1995, 53(4):438-450. http://www.cnki.com.cn/Article/CJFDTOTAL-QXXB504.006.htm
    [2]
    孙淑清, 陈隽. 异常东亚冬季风对夏季南海地区风场和热力场的影响∥气候与环境研究, 2005, 5(4): 400-415.
    [3]
    何敏, 宋文玲. 南海夏季风对中国夏季降水的影响和预测∥南海夏季风爆发和演变及其与海洋的相互作用论文集. 北京: 气象出版社, 1999: 112-116.
    [4]
    朱锦红, 王绍武.用冬季大气环流预测中国夏季降水型.北京:气象出版社, 2000.
    [5]
    陈兴芳, 宋文玲. 初夏降水的大气环流和海温特征分析及其预报∥"八·五"长期天气预报理论和方法的研究论文集. 北京: 气象出版社, 1996: 101-107.
    [6]
    陈烈庭, 吴仁广.中国东部夏季雨带类型与前期北半球500 hPa环流异常的关系.大气科学, 1998, 22(6):849-856. http://www.cnki.com.cn/Article/CJFDTOTAL-DQXK806.004.htm
    [7]
    晏红明, 段玮, 肖子牛.东亚冬季风与中国气候变化.热带气象学报, 2004, 19(4):365-376. http://www.cnki.com.cn/Article/CJFDTotal-RDQX200304003.htm
    [8]
    晏红明, 肖子牛.印度洋海温异常对亚洲季风区天气气候影响的数值模拟研究.热带气象学报, 2000, 16(1):18-27. http://www.cnki.com.cn/Article/CJFDTOTAL-RDQX200001002.htm
    • Relative Articles
    • Supplements(0)
    • Cited By
  • 加载中
  • -->

Catalog

    Figures(9)

    Get Citation
    PDF
    XML
    Article views (3285) PDF downloads(1084) Cited by()
    • Received : 2005-12-28
    • Accepted : 2006-12-29
    • Published : 2007-06-30
    Journal Online
    Contact

    © 2020 Journal of Applied Meteorological Science   京ICP备15006967号-1

    Supported by Beijing Renhe Information Technology Co. Ltd

    /

    DownLoad:  Full-Size Img  PowerPoint
    Return