The browser you are using is not supported by this website. All versions of Internet Explorer are no longer supported, either by us or Microsoft (read more here: https://www.microsoft.com/en-us/microsoft-365/windows/end-of-ie-support).

Please use a modern browser to fully experience our website, such as the newest versions of Edge, Chrome, Firefox or Safari etc.

Profile photo of Ronny Berndtsson

Ronny Berndtsson

Professor, Dep Director, MECW Dep Scientific Coordinator

Profile photo of Ronny Berndtsson

Integrated large‐scale circulation impact on rainy season precipitation in the source region of the Yangtze River

Author

  • Yiheng du
  • Ronny Berndtsson
  • Dong An
  • Linus Tielin Zhang
  • Feifei Yuan
  • Zhenchun Hao

Summary, in English

Monthly precipitation data at regular grids of 0.5° × 0.5° derived from observations during June–August 1961–2016 were used to reveal characteristics of large‐scale circulations associated with rainy season precipitation over the source region of the Yangtze River (SRYR). The integrated impact of major influencing circulation patterns was examined by principal component analysis and composites. Results showed that the first rainy season precipitation mode associates with the Southern Oscillation Index (SOI) and the Pacific Decadal Oscillation (PDO), explaining 64% of spatial and temporal rainy season precipitation variance in the region. Composites of precipitation pattern under different phases of SOI and PDO revealed that the effect of PDO on precipitation varies with the SOI phase. When out of phase with the SOI, PDO‐induced precipitation anomalies are magnified. When they are in phase, anomalies weaken or even disappear. Composites of moisture flux patterns show that large‐scale atmospheric circulation affects the strength of westerlies that transport moisture to the study area and formation of convergence. In coming decades, the PDO is likely to continue in a negative phase with La Niña (positive SOI) events, implying more precipitation during the rainy season. Consequently, this knowledge can be used to improve decision making regarding water supply and flood risk management in the SRYR.

Department/s

  • Division of Water Resources Engineering
  • Centre for Advanced Middle Eastern Studies (CMES)
  • MECW: The Middle East in the Contemporary World
  • LTH Profile Area: Water

Publishing year

2020-03-30

Language

English

Pages

2285-2295

Publication/Series

International Journal of Climatology

Volume

40

Issue

4

Document type

Journal article

Publisher

John Wiley & Sons Inc.

Topic

  • Oceanography, Hydrology and Water Resources
  • Climate Science

Keywords

  • moisture flux
  • SRYR
  • PDO
  • precipitation
  • SOI

Status

Published

Project

  • Present and future precipitation variations in the source region of the Yangtze River, China

ISBN/ISSN/Other

  • ISSN: 1097-0088