Theoretical and Applied Climatology

, Volume 104, Issue 3, pp 337–347

Statistical properties of moisture transport in East Asia and their impacts on wetness/dryness variations in North China

  • Zengxin Zhang
  • Qiang Zhang
  • Xi Chen
  • Jinchi Zhang
  • Jianwei Zhou
Original Paper

DOI: 10.1007/s00704-010-0346-z

Cite this article as:
Zhang, Z., Zhang, Q., Chen, X. et al. Theor Appl Climatol (2011) 104: 337. doi:10.1007/s00704-010-0346-z

Abstract

Dryness and wetness variations in east China were analyzed using the standardized precipitation index (SPI) based on monthly precipitation data for 1961–2005. A drying trend over North China was observed, which can be attributed to decreasing precipitation since the late 1970s. Moreover, NCAR/NCEP reanalysis dataset was used to investigate causes behind the drying trend in North China. The moisture flux on the regional boundaries of East China was calculated and a higher wavelet power spectrum for low-latitude boundaries (based on 20 and 25°N) occurred with significant periods in a 1-year band during 1961–2005; however, since 1977, a significant 1-year period can no longer be detected on the northern boundary of South China (based on 35°N). The summer moisture flux during 1961–1977, when compared to the same during 1978–2005, has increased in East China. Good matches are found between moisture alterations and precipitation changes, and are also confirmed by the periods of moisture transport along different latitudes. The significant 1-year periods of moisture transport along the mid-latitude boundary (based on 35°N) have disappeared since 1977, which could be the causes behind the drought in North China. The disappearance of the significant 1-year band of moisture transport along the mid-latitude boundary (based on 35°N) in the late 1970s could be a result of the significantly decreased moisture transport in North China in summer. When southerly winds are weakened in East Asia, the southwesterly winds can only reach the south of the lower Yangtze River, which is the major cause behind the frequent summer droughts in North China in the recent years.

Copyright information

© Springer-Verlag 2010

Authors and Affiliations

  • Zengxin Zhang
    • 1
    • 2
    • 3
  • Qiang Zhang
    • 4
    • 5
  • Xi Chen
    • 2
  • Jinchi Zhang
    • 1
  • Jianwei Zhou
    • 3
  1. 1.Jiangsu Key Laboratory of Forestry Ecological EngineeringNanjing Forestry UniversityNanjingChina
  2. 2.State Key Laboratory of Hydrology-Water Resources and Hydraulic EngineeringHohai UniversityNanjingChina
  3. 3.Key Laboratory of Meteorological Disaster of Ministry of EducationNanjing University of Information Science & TechnologyNanjingChina
  4. 4.Department of Water Resources and EnvironmentSun Yat-sen UniversityGuangzhouChina
  5. 5.Key Laboratory of Water Cycle and Water Security in Southern China of Guangdong High Education InstituteSun Yat-sen UniversityGuangzhouChina