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Long‐term change of potential evapotranspiration over southwest China and teleconnections with large‐scale climate anomalies
Author(s) -
Liu Bingjun,
Chen Xiuhong,
Li Yuan,
Chen Xiaohong
Publication year - 2017
Publication title -
international journal of climatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.58
H-Index - 166
eISSN - 1097-0088
pISSN - 0899-8418
DOI - 10.1002/joc.5309
Subject(s) - climatology , environmental science , sunshine duration , evapotranspiration , teleconnection , relative humidity , climate change , wind speed , cloud cover , atmospheric sciences , geography , meteorology , geology , el niño southern oscillation , cloud computing , oceanography , ecology , computer science , biology , operating system
Potential evapotranspiration (PET) is a sensitive factor for atmospheric and ecological systems over southwest China which is characterized by intensive karst geomorphology and fragile environment. Based on daily meteorological data of 94 stations during 1961–2013, the spatiotemporal characteristics of PET are analysed. The changing characteristics of local meteorological factors and large‐scale climatic features are also investigated to explain the potential reasons for changing PET. Study results are as follows: (1) The high‐value centre of PET with a mean value of 1097 mm a −1 locates in the south mainly resulted from the regional climatic features of higher air temperature (TEM), sunshine duration (SSD) and lower relative humidity (RHU), and the low‐value centre of PET with a mean value of 831 mm a −1 is in the northeast primarily attributed to higher RHU and weaker SSD. (2) Annual PET decreases at −10.04 mm decade −1 before the year 2000 but increases at 50.65 mm decade −1 thereafter, and the dominant factors of PET change are SSD, RHU and wind speed (WIN), with the relative contributions of 33.29, 25.42 and 22.16%, respectively. (3) The abrupt change of PET in 2000 is strongly dominated by large‐scale climatic anomalies. The strengthened 850 hPa geostrophic wind (0.51 m s −1 decade −1 ), weakened total cloud cover (−2.25% decade −1 ) and 500 hPa water vapour flux (−2.85% decade −1 ) have provided advantageous dynamic, thermal and dry conditions for PET over southwest China since the 21st century.