Changes and variability of permafrost temperatures across Siberia from 1961 through 2013

Abstract:

Studies on changes in permafrost temperatures have received much attention in Arctic scientific community in the past few decades. The objective of this study is to conduct statistical diagnosis of permafrost temperatures using soil temperature records from hydrometeorological stations across Russia. Based on soil temperature data from 26 hydrometeorological stations, we evaluate the changes in permafrost temperatures from 1961 through 2013 and their response to changes in air temperatures and seasonal snow depth. Soil temperatures from 26 stations show a significant increase at all depths with trend ranging from 0.35°C per decade at 20 cm depth to 0.23 °C per decade at 320 cm depth which is more than twice the rate of air temperature increase in the region. Enhanced soil temperature increase was found during cold seasons while no significant trends can be found during warm seasons. Permafrost temperature at 320 cm remains a significant and stable increase in each month. Besides the influence of air temperature, seasonal snow cover also played an important role in ground thermal dynamics. Considering changes both in seasonal snow depth and air temperature can explain much of the variance of soil temperature. This study further demonstrates that climate change signals inferred from permafrost temperatures are complicated by changes in seasonal snow cover.