Lake level change in China from TOPEX/Poseidon altimetry: climate implications
Cheinway Hwang(1) , Jinsheng Ning(2) , Luo Jia(3) , and Sui Chung-Hsiung(4)
National Chiao Tung University,
1001 Ta Hsueh Road,
(2) Wuhan University, 129 Luoyu Road, Wuhan 430079, China
(3) Wuhan University,, 129 Luoyu Road, Wuhan 430079, China
(4) National Central University, No.300, Jhongda Rd., 320 Jhongli , Taiwan
More than 10 years of TOPEX/Poseidon (T/P) altimeter data were used to compute time series of lake levels at six inland lakes in China. To verify our T/P data processing strategy, the T/P-derived lake levels at the Bosten Lake (west China) and at the Huron Lake (north America) are compared with lake gauge records, yielding good agreement between the T/P and the gauge results. Wavelet spectra indicate annual and interannual variations of these lake levels, which are also sensitive to climate variability. At the interannual time scale, the lake levels of Hulun (north China), Bosten (west China) and Ngangzi (east Tibet) are correlated with precipitation and ENSO, in particular they all respond to the 1997-1998 El Niño. The Bosten Lake level increased monotonically since 1993 due to increased temperature in Tianshan Mountain that feeds water into this lake. The lake levels of Hongze and Gaoyou (east China) show minor decreasing trends. The lake level of La’nga (west Tibet) decreased steadily from 1993 to 2001 with a total drop of 4 m. The lake level of Ngangzi decreased from 1/1993 to 12/1997, but after the peak of the 1997-1998 El Niño the slope was reversed and the lake level increased monotonically till present.