Faster increase in evapotranspiration in permafrost-dominated basins in the warming Pan-Arctic

•Evapotranspiration (ET) increased largely across the Pan-Arctic during 1981–2020.•Permafrost-dominated basins showed faster increases in ET than those with less permafrost.•Permafrost thawing may contribute to increased evapotranspiration. Land evapotranspiration (ET) is a key factor in the hydrological cycle and is particularly sensitive to climate change. In the past few decades, the Pan-Arctic region has witnessed a strong warming trend, causing substantial changes in ground surface conditions. However, it remains poorly understood how ET varies across such a region. Here, we investigated the spatial–temporal changes in ET over six large Pan-Arctic river basins using corrected ET estimates from GLEAM and ERA5-Land during 1981–2020. The 40-year mean annual ET in the Ob, Yenisei, Lena, Kolyma, Yukon, and Mackenzie River basins were approximately 366 mm·yr−1, 271 mm·yr−1, 228 mm·yr−1, 239 mm·yr−1, 278 mm·yr−1, and 295 mm·yr−1, respectively. Climatologically, permafrost-dominated basins tend to have lower ET than those with less permafrost. Temporally, the annual ET in permafrost-dominated basins has increased faster than that in less permafrost-developed basins over the past four decades. This increase is particularly prominent in the Kolyma River basin (completely covered by permafrost), where the significant trend in ET (7.5 mm·decade−1, p