ABSTRACT
Recent hypotheses, based on atmospheric records and models, suggest that permafrost carbon (PF-C) accumulated during the last glaciation may have been an important source for the atmospheric CO2 rise during post-glacial warming. However, direct physical indications for such PF-C release have so far been absent. Here we use the Laptev Sea (Arctic Ocean) as an archive to investigate PF-C destabilization during the last glacial-interglacial period. Our results show evidence for massive supply of PF-C from Siberian soils as a result of severe active layer deepening in response to the warming. Thawing of PF-C must also have brought about an enhanced organic matter respiration and, thus, these findings suggest that PF-C may indeed have been an important source of CO2 across the extensive permafrost domain. The results challenge current paradigms on the post-glacial CO2 rise and, at the same time, serve as a harbinger for possible consequences of the present-day warming of PF-C soils.
ABSTRACT
Investigations of 3d transition metal (TM) compounds by means of linear dichroism in TM K-NEXAFS will be reported. At this, the decomposition of the angular-dependent NEXAFS into orbital projected components are important problems. A survey is given on methods how to extract information on the geometrical, electronic and magnetic structure from linearly polarized NEXAFS and EXAFS spectra. New results on CuO and CuPc (Copper Phthalocyanine) are reported. A reference is given to the novel method for spin-resolving of NEXAFS by analysis of resonantly scattered X-ray core lines.
