Lake ice phenology is a sensitive indicator reflecting global warming. In this article, the long-term changes in lake ice phenology of the second-largest lake at Tibetan Plateau (i.e., the Nam Co) in response to climate change are investigated based on mathematical modeling. The model has been testified capable of reproducing daily surface temperature of the lake in both frozen and unfrozen seasons. The lake ice phenology determined according to the simulated lake surface temperature is found consistent with that derived from satellite observations. For the Nam Co during the period 1978–2017, the freezing date has been delayed (reached up to 0.57 days/year), whereas the thawing date became earlier (−0.23 days/year). The trend of lake ice phenology is significantly correlated to the annual minimal lake surface and air temperature. Modeling experiment suggests that lake ice phenology of the Nam Co is very sensitive to a warmer climate. Under warmer future, much later freezing date and earlier thawing date are expected; hence the ice-covering duration would be significantly shortened.

中文翻译：

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青藏高原湖冰物候对气候变化的响应

湖冰物候是反映全球变暖的敏感指标。本文基于数学模型研究了青藏高原第二大湖（即纳木错）湖冰物候随气候变化的长期变化。该模型已被证明能够在结冰和未结冰季节再现湖泊的每日表面温度。根据模拟湖面温度确定的湖冰物候与卫星观测结果一致。Nam Co 在 1978-2017 年期间，冻结日期延迟（达到 0.57 天/年），而解冻日期提前（-0.23 天/年）。湖冰物候变化趋势与年最小湖面和气温显着相关。模拟实验表明，Nam Co 的湖冰物候对温暖的气候非常敏感。在温暖的未来，预计冻结日期和解冻日期会更晚；因此，覆冰时间将大大缩短。