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The ways in which natural ecosystems respond to global change have become an urgent concern to society. Lakes play a pivotal role in ecosystem changes because of their central position within watersheds and their involvement in various endogenous and cross-system ecological and biogeochemical processes, leaving natural archives accumulated in sediments over time. However, how lake ecosystems have responded to atmospheric changes during the past few centuries is still not fully understood. To analyse the process in more detail, we conducted a case study at Lake Genco, a remote alpine on the southeastern Qinghai-Tibetan Plateau (QTP) and recovered a 170-year history of lake's ecosystem from a 210Pb-dated sediment core. The air temperature increased between 1900 and 1950 CE and 1980 and 2020 CE. Geochemical and physical proxies (magnetic susceptibility, Sr/Ba, K/Al, Na/Al, Ti, Pb, P flux, TN and δ15N org) indicated greater degrees of weathering and erosion, and higher nutrient loadings as terrestrial systems responded to atmospheric changes after 1900 CE. Higher primary aquatic productivity, richer biodiversity and weaker structural stability were found in Lake Genco between 1852 and 2017 CE, although the ecological response was quiet in terms of the compositional change in the diatom community, which was generally dominated by small planktonic Cyclotella ocellata. During warmer periods, diatom PC1 changed directionally due to the overall increase in the abundance of tychoplanktonic Fragilaria construens and periphytic Achnanthes minutissima and the decreasing abundance (∼10%) of C. ocellata. This study provides empirical evidence that ecological changes in remote lakes rely on interactions between the atmosphere and the landscape and helps us to understand the complexity of the various impacts of global climate change. More local and regional studies are needed to generalise the mechanism of biological responses to atmospheric changes in remote lakes, especially in the QTP. • Remote lake ecosystems' responses to climate change have been a key concern in the global warming context. • Modest ecological changes were revealed over the past 170 years in a small high-altitude lake of the southeast Tibetan Plateau. • The relative abundance of planktonic Cyclotella ocellata decreased while primary productivity and biodiversity increased. • Lake surface area may have determined the local ecological response of lakes to atmospheric changes in this region. [ABSTRACT FROM AUTHOR]

• A new retracker named INPPTR which can solve the disadvantage of current retrackers are represented. • The retracker can extracts more accurate main peaks of the waveform with serious waveform pollution. • For the SARin data, the accuracy of INPPTR is significantly higher than the other three retrackers. • For the SAR data, the accuracy of INPPTR is equivalent to other retrackers. As an important technology for measuring water levels, satellite altimetry has been widely using in the lake, river, and wetland in the past two decades. However, the waveform pollution limits its application in areas with complex topography, the accuracy of the existing retracking algorithms need to be further improved. In this study, a new retracking algorithm, named Improved Narrow Primary Peak Threshold Retracking algorithm (INPPTR), based on Narrow Primary Peak Threshold Retracking algorithm (NPPTR) is presented. This retracking algorithm eliminates the noise in the waveform, extracts more accurate main peaks of the waveform, and performs Gaussian fitting on the main peaks with serious waveform pollution. Finally, the more stable water levels in areas with complex terrain can be obtained from Cryosat-2 Synthetic Aperture Radar Interferometer (SARin) waveform. To verify the accuracy of retracking algorithms, the water level time series of eight lakes and one river were retrieved using INPPTR and other three retracking algorithms (NPPTR, NPPOR and MWaPP), then were compared to the in-situ data. For Qinghai Lake, Namco Lake, Selin Lake, Zhair Namco Lake, Issyk Lake, Great Salt Lake, Tahoe Lake and Great Slave Lake, where SARin mode is used, and the root mean squared errors (RMSE) obtained by INPPTR are 18.09 cm, 21.69 cm, 20.48 cm, 34.82 cm, 17.39 cm, 39.68 cm, 26.25 cm and 18.43 cm, respectively. Compared with NPPTR, the RMSE of INPPTR is reduced by 9.91 %, 14.83 %, 7.62 %, 14.74 %, 6.70 %, 4.11 %, 105.37 % and 25.02 %, respectively. For the Amazon River, the RMSE of INPPTR is 58.24 cm, compared with the other three retracking algorithms, the RMSE obtained by INPPTR is the lowest as well. In summary, the accuracy of INPPTR is significantly higher than the other three retracking algorithms, and INPPTR can process Cryosat-2 SARin data effectively and provide more stable and effective water levels, laying the foundation for long-term, high-accuracy water levels monitoring of inland water bodies with complex terrain. [ABSTRACT FROM AUTHOR]