Potential evapotranspiration (PET) is a key factor involved in regional and global Earth system processes. This is particularly important for Arctic region, which faces amplified warming and is vulnerable to climate change. In this study, we estimate the PET during 1975-2014 at 190 meteorological stations in Siberian river basins using three frequently used models including a combination model (Penman–Monteith, PM), a radiation-based model (Priestley–Taylor, PT), and a temperature-based model (Hamon, H). Based on the estimated PET, the spatiotemporal variations, and differences among the three models are analyzed, and the PET changes are attributed to the changes in meteorological drivers. The results show that the annual values estimated by PM and PT models are close and are much larger than that estimated by H model. The trends of PET from PM model are generally insignificant while these from H model exhibit widespread increase in much of the Yenisey and Lena river basins. The contributions of changes in air temperature and net radiation to PET changes are less than 20% at most of stations, while the increasing VPD and decreasing wind speed contribute more than 80% to the changes of PET. This finding highlights the importance of VPD and wind speed in PET estimates in the Siberian river basins. Using different PET models can substantially affect estimates of aridity index. It further indicates that cautions must be taken when selecting PET model for hydrological and climate change studies in the arctic region.

潜在的蒸散量（PET）是参与区域和全球地球系统过程的关键因素。对于北极地区而言，这一点尤其重要，因为北极地区的气候变暖加剧，容易受到气候变化的影响。在这项研究中，我们使用三种常用模型（包括组合模型（Penman–Monteith，PM），辐射模型（Priestley–Taylor，PT），以及基于温度的模型（Hamon，H）。基于估计的PET，分析了三个模型之间的时空变化和差异，并将PET的变化归因于气象驱动因素的变化。结果表明，由PM和PT模型估算的年均值接近且远大于由H模型估算的年均值。PM模型的PET趋势通常微不足道，而H模型的PET趋势在Yenisey和Lena流域的大部分地区表现出广泛的增长。在大多数站点中，气温和净辐射变化对PET变化的贡献小于20％，而VPD的增加和风速的下降对PET变化的贡献超过80％。这一发现凸显了VPD和风速在西伯利亚流域PET估算中的重要性。使用不同的PET模型会严重影响干旱指数的估算。它进一步表明，在为北极地区的水文和气候变化研究选择PET模型时，必须谨慎行事。在大多数站点中，气温和净辐射变化对PET变化的贡献小于20％，而VPD的增加和风速的下降对PET变化的贡献超过80％。这一发现凸显了VPD和风速在西伯利亚流域PET估算中的重要性。使用不同的PET模型会严重影响干旱指数的估算。它进一步表明，在为北极地区的水文和气候变化研究选择PET模型时，必须谨慎行事。在大多数站点中，气温和净辐射变化对PET变化的贡献小于20％，而VPD的增加和风速的下降对PET变化的贡献超过80％。这一发现凸显了VPD和风速在西伯利亚流域PET估算中的重要性。使用不同的PET模型会严重影响干旱指数的估算。它进一步表明，在为北极地区的水文和气候变化研究选择PET模型时，必须谨慎行事。使用不同的PET模型会严重影响干旱指数的估算。它进一步表明，在为北极地区的水文和气候变化研究选择PET模型时，必须谨慎行事。使用不同的PET模型会严重影响干旱指数的估算。它进一步表明，在为北极地区的水文和气候变化研究选择PET模型时，必须谨慎行事。