Detecting Lake Level Change From 1992 to 2019 of Zhari Namco in Tibet Using Altimetry Data of TOPEX/Poseidon and Jason-1/2/3 Missions

Zhari Namco, a large lake in the Tibetan Plateau (TP), is sensitive to climate and environmental change. However, it difficult retrieve accurate continuous levels for Namco. A robust strategy, including atmospheric delay correction, waveform retracking, outlier deletion, inter-satellite adjustment, proposed generate long-term series of Namco through multi-altimeter data. Apparent biases are found troposphere correction from different altimeter products adjusted using an identical model. The threshold (20%) algorithm employed retracking. two-step method combining sliding median filter 2? criterion used eliminate outliers. Tandem mission data altimeters estimate bias. Finally, 27-year-long level time constructed TOPEX/Poseidon-Jason1/2/3 (T/P-Jason1/2/3) 1992 2019, resulting accuracy 10.1 cm T/P-Jason1/2/3. Temperature, precipitation, area, equivalent water height, situ gauge validation. correlation coefficient more than 0.90 can be observed between this result Compared with previous studies existing database products, our yields sequences best observational quality longest monitoring indicates that has increased by ? 5.7 m, overall trend 0.14 ± 0.01 m/yr, showing fluctuating rate (1992–1999: ?0.25 0.05 2000–2008: 0.26 0.04 2009–2016: ?0.05 0.03 2017–2019: 1.34 0.34 m/yr). These findings will enhance understanding budget effect change TP.