The timing of the seasonal freeze-thaw cycle of arctic lakes affects ecological processes and land-atmosphere energy fluxes. We carried out detailed ice-phenology mapping of arctic lakes, based on daily surface-reflectance time series for 2000–2013 from MODIS at 250 m spatial resolution. We used over 13,300 lakes, area >1 km2, in five study areas distributed evenly across the circumpolar Arctic — the first such phenological dataset. All areas showed significant trends towards an earlier break-up, stronger than previously reported. The mean shift in break-up start ranged from −0.10 days/year (Northern Europe) to −1.05 days/year (central Siberia); the shift in break-up end was between −0.14 and −0.72 days/year. Finally, we explored the effect of temperature on break-up timing and compared results among study areas. The 0 °C isotherm shows the strongest relationship (r = 0.56–0.81) in all study areas. If the trend in early break-up continues, rapidly changing ice phenology will likely generate significant, arctic-wide impacts.
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机译：北极湖泊季节性冻融周期的时间会影响生态过程和陆地-大气能量通量。我们根据MODIS在250 m空间分辨率下2000-2013年的每日表面反射时间序列，对北极湖进行了详细的冰物候学制图。我们在五个研究区域中使用了13,300个湖泊，面积> 1 km 2 ，这些区域均匀地分布在极地北极上，这是第一个此类物候数据集。所有领域均显示出较早分裂的显着趋势，比先前报道的要强大。分手开始的平均变化范围为-0.10天/年（北欧）至-1.05天/年（中西伯利亚）；分手结束时间的变动介于-0.14至-0.72天/年之间。最后，我们探索了温度对分手时间的影响，并比较了研究区域之间的结果。在所有研究区域中，0°C等温线显示出最强的关系（r = 0.56-0.81）。如果早期分裂的趋势继续下去，迅速改变的冰物候态将可能产生重大的北极影响。
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