Climate of the Past Discussions www.clim-past-discuss.net 1814-9340 1814-9359 3 2 2007 10.5194/cpd-3-631-2007 http://www.clim-past-discuss.net/3/631/2007/ http://www.clim-past-discuss.net/3/631/2007/cpd-3-631-2007.html http://www.clim-past-discuss.net/3/631/2007/cpd-3-631-2007.pdf 631 653 2007-03-20 Repeated temperature logs from the sites of the Czech, Slovenian and Portuguese borehole climate stations J. Šafanda jsa@ig.cas.cz D. Rajver A. Correia P. Dědeček Geophysical Institute Prague, Boční II/1401, 141 31 Praha, Czech Republic Geological Survey of Slovenia, Dimičeva 14, Ljubljana, Slovenia Department of Physics, University of Evora, 7000 Evora, Portugal Two borehole climate stations were established in Slovenia and Portugal within a joint Czech-Slovenian-Portuguese project in the years 2003–2005. They completed the older Czech station, which has been operating since the year 1994. We report here on the repeated temperature logs carried out within 6 boreholes at the sites of the stations and their surroundings within a time span of 8–20 years (1985–2005). The repeated logs revealed subsurface warming in all the boreholes amounting to 0.2–0.6°C below the depth of the annual run at 20 m. The depth of the Czech borehole (140 m) and the Portuguese borehole (180 m) was sufficient enough for a reconstruction of the ground surface temperature (GST) history of the last 150–200 years and their comparison with the surface air temperature (SAT) series measured in Prague (since 1771) and Lisbon (1856), respectively. The reconstructed histories reproduce reasonably well the amplitude of the recent warming, 1–1.5°C above the long-term mean. The depth of all four Slovenian boreholes, 100 m, did not allow the inversion, but it was possible to apply it to a deep borehole 5 km apart from the Slovenian station. 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