Temperature anomalies in central and eastern Tibetan Plateau in relation to general circulation patterns during 1951-1993

Abstract

Temperature anomalies at 44 stations with fairly complete records for the period 1961–1987 were selected from a 74-station database and were analysed by principal component analysis (PCA), producing three major subregions in the eastern part of the Tibetan Plateau. The first subregion is located in the south-central portion of the Tibetan Plateau. The second subregion represents the northeastern portion of the Plateau, mostly in the Qinghai Province, while the third subregion represents the western Sichuan Province. Temperature data during 1951–1993 for 48 stations within these subregions were used to construct temperature anomaly records. In correlation field analyses between subregional temperature anomalies and 500 hPa geopotential height anomalies, it was found that the temperatures in each region were associated with the pressure height anomaly patterns in different ways. In addition, different patterns were identified during cold (October–March) and warm (April–September) seasons. Major extratropical teleconnections in the realm of Eurasia and western Pacific and El Niño–Southern Oscillation (ENSO) events were significantly correlated with the subregional temperature anomalies. Results of multiple regression analyses showed that the macroscale circulation patterns explained up to 26% of the total variation in subregional temperature anomalies during the cold season and 16% of the variation during the warm season. Copyright © 2000 Royal Meteorological Society