Spatial-temporal variations of lake ice phenology in the Hoh Xil region from 2000 to 2011

Abstract

Lake ice phenology, i.e. the timing of freeze-up and break-up and the duration of the ice cover, is regarded as an important indicator of changes in regional climate. Based on the boundary data of lakes, some moderate-high resolution remote sensing datasets including MODIS and Landsat TM/ETM+ images and the meteorological data, the spatial-temporal variations of lake ice phenology in the Hoh Xil region during the period 2000-2011 were analyzed by using RS and GIS technology. And the factors affecting the lake ice phenology were also identified. Some conclusions can be drawn as follows. (1) The time of freeze-up start (FUS) and freeze-up end (FUE) of lake ice appeared in the late October-early November, mid-November-early December, respectively. The duration of lake ice freeze-up was about half a month. The time of break-up start (BUS) and break-up end (BUE) of lake ice were relatively dispersed, and appeared in the early February-early June, early May-early June, respectively. The average ice duration (ID) and the complete ice duration (CID) of lakes were 196 days and 181 days, respectively. (2) The phenology of lake ice in the Hoh Xil region changed dramatically in the last 10 years. Specifically, the FUS and FUE time of lake ice showed an increasingly delaying trend. In contrast, the BUS and BUE time of lake ice presented an advance. This led to the reduction of the ID and CID of lake. The average rates of ID and CID were-2.21 d/a and-1.91 d/a, respectively. (3) The variations of phenology and evolution of lake ice were a result of local and climatic factors. The temperature, lake area, salinity and shape of the shoreline were the main factors affecting the phenology of lake ice. However, the other factors such as the thermal capacity and the geological structure of lake should not be ignored as well. (4) The spatial process of lake ice freeze-up was contrary to its break-up process. The type of lake ice extending from one side of lakeshore to the opposite side was the most in the Hoh Xil region.

Variations of Lake Ice Phenology on the Tibetan Plateau From 2001 to 2017 Based on MODIS Data

“…Consistent with the results of this study, Dogaicoring Qangco and Lexiewudan Co are the rare lakes in this region with advancing freezeup dates and delayed breakup dates, and the reason for these changes will be discussed in the following section. However, in this study, the freezeup start and breakup end dates of Taiyang Lake have been delayed over 17 years, which is different from an advancing breakup end date in Yao et al (). From 2000 to 2011, the breakup end date of Taiyang Lake did show an advancing trend with a rate of 1.51 day/year.…”

“…Lakes with long freezeup durations in the Inner basin such as Qinghai Lake, Selin Co, and Ngangla Ringco are all lakes with areas larger than 500 km 2 (Table ). In theory, lakes with higher mineralizations should have a lower ice point, as well as a later freezeup date, earlier breakup date, and shorter ice cover duration (Yao et al, ). Lakes, such as Selin Co, Nam Co, and Tu Co, with large areas but low mineralization may affect the results of the correlation analysis (Table ).…”

“…Shallow lakes require less heat to freezeup and have earlier freezeup dates (Kropáček et al, ; Yao et al, ). The physical characteristics determine the thermodynamics of a lake and sometimes have more of an impact on the ice phenology than do the chemical conditions.…”

“…As “the Third Pole of the Earth,” the TP is very sensitive to global climate change (Kang et al, ; Liu & Chen, ; Qiu, ). Changes in air and water surface temperatures related to climatic changes are important factors in the lake ice phenology changes (Adrian et al, ; Dörnhöfer & Oppelt, ; Yao et al, ; Zhang, Yao, Xie, Zhang, et al, ). At the same time, the state and type of lake ice and their change to open water system in turn affect the local or regional climate (Brown & Duguay, ; Rouse et al, ).…”

Numerical study on the response of the largest lake in China to climate change

“…The variations in break-up and freeze-up dates are sensitive to the meteorological conditions, e.g. air temperature, solar radiation and wind (Duguay et al, 2006;Latifovic and Pouliot, 2007;Ye et al, 2011;Kirillin et al, 2012;Yao et al, 2016). In the SL experiment, the simulated maximum ice thickness demonstrated a negative correlation of −0.52 (p < 0.01) to the mean air temperature anomaly from January to April in Qinghai Lake.…”