Thermal Regime of A Deep Temperate Lake and Its Response to Climate Change: Lake Kuttara, Japan
Thermal Regime of A Deep Temperate Lake and Its Response to Climate Change: Lake Kuttara, Japan
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DOI：
10.3390/hydrology5010017
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发表时间：
2018-02
期刊：
影响因子：
3.2
通讯作者：
K. Chikita;H. Oyagi;Tadao Aiyama;M. Okada;H. Sakamoto;T. Itaya
中科院分区：
文献类型：
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作者：
K. Chikita;H. Oyagi;Tadao Aiyama;M. Okada;H. Sakamoto;T. Itaya
日本北海道库塔拉湖是一个深温带湖泊（最深处148米），世纪的每个冬天都完全被冰层覆盖。然而，在21世纪世纪，该湖出现了三次冬季无冰条件，这可能是由于全球变暖。为了了解湖泊的热状况如何响应气候变化，在湖泊平均水温的变化，从热存储的变化计算通过集成观测水温超过水深和通过数值计算的热收支组件的水文气象数据的基础上。结果表明，由热量收支计算的湖泊平均水温的时间变化与实测水温的时间变化是非常合理的（决定系数R2 = 0.969）。最低湖平均温度为-1.87 °C，参考6.80 °C的零水平。库塔拉附近一个气象站1978-2017年的数据表明，气温（+0.024 °C/年）和风速（-0.010 m/s/年）存在显著（低于5%水平）的长期趋势。为了评估气候变化对封冻模式的影响，对计算的湖泊平均水温进行了敏感性分析。人们注意到，二十年后，该湖可能每两年一次无冰。
A deep temperate lake, Lake Kuttara, Hokkaido, Japan (148 m deep at maximum) was completely ice-covered every winter in the 20th century. However, ice-free conditions of the lake over winter occurred three times in the 21st century, which is probably due to global warming. In order to understand how thermal regime of the lake responds to climate change, a change in lake mean water temperature from the heat storage change was calculated by integrating observed water temperature over water depths and by numerical calculation of heat budget components based on hydrometeorological data. As a result, a temporal variation of lake mean water temperature from the heat budget calculation was very reasonable to that from the observed water temperature (determination coefficient R2 = 0.969). The lowest lake mean temperature for non-freeze was then evaluated at −1.87 °C, referring to the zero level at 6.80 °C. The 1978–2017 data at a meteorological station near Kuttara indicated that there are significant (less than 5% level) long-term trends for air temperature (+0.024 °C/year) and wind speed (−0.010 m/s/year). In order to evaluate the effects of climate change on freeze-up patterns, a sensitivity analysis was carried out for the calculated lake mean water temperature. It is noted that, after two decades, the lake could be ice-free once per every two years.