Combined ICESat and CryoSat-2 Altimetry for Accessing Water Level Dynamics of Tibetan Lakes over 2003–2014
نویسندگان
چکیده
Long-term observations of lake water level are essential to our understanding of the evolution of Tibetan lake system. CryoSat-2 radar altimetry data over the Tibetan Plateau (2010–2014, P2) is used to extend lake level measurements from ICESat laser altimetry (2003–2009, P1). This study evaluates the performance of CryoSat-2 data by comparing with gauge-based water levels that are calibrated by ICESat-observed water level time series, and quantifies the uncertainty of water-level change rate estimates from satellite altimetry measurements. We completely investigate the 131 lakes that were observed by both ICESat and CryoSat-2. The mean change rate of water level for all of examined lakes in P2 (0.19 ± 0.03 m·year–1) is slightly lower than that (0.21 ± 0.02 m·year–1) observed in P1. The extended lake level time series also indicates that, in the past few years, lakes in the Northern Changtang (especially in Hol Xil) showed accelerated growth; and that the extensive lake level rises north to the Gangdise Mountains, during 2003–2009, were found dampened during the CryoSat-2 observation period. The spatio-temporal heterogeneity of precipitation observed from weather stations can be used to partly explain the observed temporal pattern of lake level changes over different sub-zones of the plateau. OPEN ACCESS
منابع مشابه
ICESat derived elevation changes of Tibetan lakes between 2003 and 2009
The Tibetan plateau contains thousands of small and big lakes. Changes in the water level of these lakes can be an important indicator for the water balance of the Tibetan plateau, but were until now extremely difficult to monitor: performing continuous in situ measurements at a large number of lakes is not feasible because of their remoteness, while radar altimetry is only capable of monitorin...
متن کاملCryoSat-2 Altimetry Applications over Rivers and Lakes
Monitoring the variation of rivers and lakes is of great importance. Satellite radar altimetry is a promising technology to do this on a regional to global scale. Satellite radar altimetry data has been used successfully to observe water levels in lakes and (large) rivers, and has also been combined with hydrologic/hydrodynamic models. Except CryoSat-2, all radar altimetry missions have been op...
متن کاملInternational Workshop on Terrestrial Water Cycle Observation and Modeling from Space: Innovation and Reliability of Data Products Determining geometric links between glaciers and lakes on the Tibetan plateau
The Tibetan plateau and surrounding mountain ranges contain the largest amount of ice outside the polar region. The Tibetan plateau also contains more than one thousand lakes and is the origin of a large part of the water resources of South and East Asia, the most densely populated regions on earth. Recent studies concluded that the glacial area on the Tibetan plateau and surroundings has decre...
متن کاملThe Impact of Geophysical Corrections on Sea-Ice Freeboard Retrieved from Satellite Altimetry
Satellite altimetry is the only method to monitor global changes in sea-ice thickness and volume over decades. Such missions (e.g., ERS, Envisat, ICESat, CryoSat-2) are based on the conversion of freeboard into thickness by assuming hydrostatic equilibrium. Freeboard, the height of the ice above the water level, is therefore a crucial parameter. Freeboard is a relative quantity, computed by sub...
متن کاملAssessing Orographic Variability in Glacial Thickness Changes at the Tibetan Plateau Using ICESat Laser Altimetry
Monitoring glacier changes is essential for estimating the water mass balance of the Tibetan Plateau. In this study, we exploit ICESat laser altimetry data in combination with the SRTM DEM and the GLIMS glacier mask to estimate trends in change in glacial thickness between 2003 and 2009 on the whole Tibetan Plateau. Considering acquisition conditions of ICESat measurements and terrain surface c...
متن کامل