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Scanning micro-X-ray fluorescence analysis with synchrotron radiation was applied to obtain the depth-variation profiles of element compositions of banded clays in Peyungda Lake (Krasnoyarsk krai, Evenkia) located 30 km southwest of the epicenter of the Tunguska event (1908). The age model was confirmed by a dated layer of anomalous thickness related to the fall and explosion of the Tunguska Cosmic Body (TCB). The variations in the element content in dated core layers were compared with the instrumental meteorological observation data over the last century. The regional average annual temperature and element compositions of the coeval bottom sediments (transfer function) were found to be interrelated. The approximation of the transfer function to the sampling depth of the sedimentary section made it possible to reconstruct the air temperature in the studied region over the past 1000 years. The average annual temperature reconstructions in the study area compared with the global temperature reconstructions in the Arctic region for the same period made it possible to reveal general trends and extreme values. [ABSTRACT FROM AUTHOR]

Abstract: Laboratory experiments were conducted in a hermetically sealed growth chamber with two soil samples obtained from the arctic tundra zone with different levels of moisture. Samples were maintained at a growing season typical of the region from which they were taken, and for the sample with a high level of moisture it was made twice: with the temperature in accord with natural conditions and one increased by 2°C. It has been shown that heating of the overmoistened tundra soil by 2°C can increased the average carbon dioxide emissions by almost two times (from 75 to 100-150 mg m-2 h-1). Upon the application of heat, no significant increase in methane emission was observed. [ABSTRACT FROM AUTHOR]