Tibetan Plateau summer precipitation: covariability with circulation indices
Relations between Tibetan Plateau precipitation and large-scale climate indices are studied based on the Standardized Precipitation Index (SPI) and the boreal summer season. The focus is on the decadal variability of links between the large-scale circulation and the plateau drought and wetness. Analysis of teleconnectivity of the continental northern hemisphere standardized summer precipitation reveals the Tibetan Plateau as a major SPI teleconnectivity center in south-eastern Asia connecting remote correlation patterns over Eurasia. Employing a moving window approach, changes in covariability and synchronizations between Tibetan Plateau summer SPI and climate indices are analyzed on decadal time scales. Decadal variability in the relationships between Tibetan Plateau summer SPI and the large-scale climate system is characterized by three shifts related to changes in the North Atlantic, the Indian Ocean, and the tropical Pacific. Changes in the North Atlantic variability (North Atlantic Oscillation) result in a stable level of Tibetan Plateau summer SPI variability; the response to changes in tropical Pacific variability is prominent in various indices such as Asian monsoon, Pacific/North America, and East Atlantic/Western Russia pattern.
KeywordsTibetan Plateau Standardize Precipitation Index Pacific Decadal Oscillation Western North Pacific Circulation Index
Referees’ comments are appreciated, which helped to improve the manuscript. Financial support by the Deutsche Forschungsgemeinschaft and the Klimacampus Hamburg is appreciated. KF and XZ acknowledge support of the Max Planck Society. NCEP Reanalysis derived data is provided by the NOAA/OAR/ESRL PSD, Boulder, Colorado, USA, from their Web site at http://www.esrl.noaa.gov/psd/, as is the AMO index. Further data is obtained from the DWD, the CPC at NOAA, the FRCGCC, the International Pacific Research Center, and the Joint Institute for the Study of the Atmosphere and Ocean.
- Beck C, Grieser J, Rudolf B (2005) A new monthly precipitation climatology for the global land areas for the period 1951 to 2000. Climate Status Report No. 2004, German Weather Service: Offenbach, pp. 181–190.Google Scholar
- Efron B, Tibshirani RJ (1993) An introduction to the Bootstrap, Monographs on Statistics and Applied Probability, Vol. 57. Chapman & Hall/CRC, 436 pp.Google Scholar
- Flohn H (1968) Contributions to a meteorology of the Tibetan highlands. Atmospheric Science Paper 130.Google Scholar
- Fowler HJ, Archer DR (2005) Hydro-climatological variability in the upper Indus basin and implications for water resources. Regional hydrological impacts of climatic change—impact assessment and decision making. IAHS Publ 295:131–138Google Scholar
- Kumar K, Rajagopalan B, Cane MA (1999) On the weakening relationship between the Indian monsoon and ENSO. Science 284: 2156–2159, doi: 10.1126/science.284.5423.2156, http://www.sciencemag.org/cgi/reprint/284/5423/2156.pdf.
- McKee TB, Doeskin NJ, Kleist J (1993) The relationship of drought frequency and duration to time scales. 8th Conference on applied climatology, American Meteorological Society, Anaheim, Canada, 179–184.Google Scholar
- NOAA (2005–2008) Northern hemisphere teleconnection patterns. Online resource: http://www.cpc.noaa.gov/data/teledoc/telecontents.shtml.
- NOAA (2008) Previous ENSO events. Online resource: http://www.cpc.noaa.gov/products/monitoring_and_data/ENSO_connections.shtml.
- Saeed S, Müller WA, Hagemann S, Jacob D (2010) Circumglobal wave train and the summer monsoon over northwestern India and Pakistan: the explicit role of the surface heat low. Climate Dynamics. In press. doi: 10.1007/s00382-010-0888-x
- Saji NH, Goswami BN, Vinayachandran PN, Yamagata T (1999) A dipole mode in the tropical Indian Ocean. Nature 401:361–363Google Scholar