Recent regional warming across the Siberian lowlands: a comparison between permafrost and non-permafrost areas

The northern mid-high latitudes experience climate warming much faster than the global average. However, the difference in the temperature change rates between permafrost and non-permafrost zones remains unclear. In this study, we investigated the temporal changes in temperature means and extremes across the Siberian lowlands (<500 m) over the past six decades (1960-2019) using in situ observations and reanalysis data. The results show that permafrost zones (0.39 degrees C/decade) have warmed faster than non-permafrost zones (0.31 degrees C/decade). The minimum values of the daily maximum (TXn) and minimum (TNn) temperatures changed faster than their maximum values (TXx, TNx), suggesting that low minimum temperatures increase faster, as evidenced by the considerably higher warming rate in the cool season (October-April, 0.43 +/- 0.10 degrees C/decade, n= 126) than that in the warm season (May-September, 0.25 +/- 0.08 degrees C/decade, n= 119). The change rates of TXx and TNx in permafrost areas were 2-3 times greater than those in non-permafrost areas; however, over the last ten years, TXx and TNx in non-permafrost areas showed decreasing trends. Moreover, faster-warming permafrost regions do not exhibit a faster increase in surface net solar radiation than slower-warming non-permafrost regions. While our findings suggest that carbon emissions from thawing soils are likely a potential driver of rapid warming in permafrost-dominated regions, the potential feedback between ground thawing and climate warming in permafrost regions remains uncertain.

Automated summary

The warming rates of permafrost zones in the northern mid-high latitudes are faster than those of non-permafrost zones, especially during the cool season. However, the maximum and minimum temperatures have shown decreasing trends in non-permafrost areas over the past decade, and the exposure to solar radiation is not higher in faster-warming permafrost regions compared to slower-warming non-permafrost regions.