Climate warming in the Czech Republic: Evidence stored in shallow subsurface

Abstract

Present-day climate is undergoing a general warming, which is manifested by the steadily increasing mean annual air temperatures. Data from the local Czech meteorological stations were completed with the long-term monitoring of the subsurface temperature field as the response to the changing surface conditions. Temperature changes on the surface propagate into the subsurface and due to the fact that the Earth's surface effectively filters out high frequency variations, such as daily and annual, temperature records from depth below approx. 20-30 m may suitably evidence climate evolution on a longer timescale and help in climate reconstruction. Subsurface temperatures were monitored at three experimental sites (Sporilov, Kocelovice and Potucky) to the depth of 40-50 m in different environmental conditions. Additional experiments focused to describe the GST-SAT coupling (ground surface temperature vs. surface air temperature) and to assess the effect of snow cover, ground freezing and rain precipitation on the forcing mechanism. Monitoring series clearly confirmed warming rates ranging from 0.02 to 0.04 K/year, which are in good agreement with meteorological data as well as with the results of the previous inversion program to extract the recent climate signal from the borehole temperature logs. The results also seem to sustain a potential anthropogenic component contributing to a more pronounced warming in areas of large urban agglomeration. © Springer Science + Business Media B.V. 2010.