PHYSICAL-MATHEMATICAL PROBLEM OF THE RECENT CLIMATE RECONSTRUCTION FROM SUBSURFACE TEMPERATURE LOGS

Conventional methods of studying the recent climate history are associated with statistical processing of accomplished meteorological data. These investigations have focused attention on meteorological records of air temperature, which can provide information on the only last 100-200 years. Number of the records is absolutely insufficient and their areal coverage is limited, some oldest meteorological stations may have been affected by local warming connected with urban and industrial growth. At the same time significant climate changes are accompanied by the corresponding variations in the Earth's surface (soil) temperature. This effect is based on the known physical law that temperature waves at the surface propagate downward into the subsurface with an amplitude attenuation and time delay increasing with depth. Earth's temperature profiles, measured by precise temperature logging T(z) in boreholes to depth of about 300-400 meters, have a “memory” on what has happened on the surface during approximately three-four last centuries. In the present paper authors demonstrate application of the developed computer program calculating the temperature anomalies versus depth for four different models of changing the “surface” temperatures. From the four constructed physical-mathematical models has been selected a model of climate sudden changing. This investigation has been conducted within the UNESCO program “Past Climate Change Inferred from the Analysis of the Underground Temperature Field”.