Magnetic characteristics of insoluble microparticles in ice core (Nojingkangsang) from the southern Tibetan Plateau and its environmental significance.

Insoluble microparticles in ice cores are related closely to the transportation of eolian dust, and thus are important natural media to reconstruct climate change. In this study, we conducted a systematic mineral-magnetic investigation of insoluble microparticles in the Nojingkangsang ice core (29°2.1′N, 90°11.88′E, 5950 m) from the Southern Tibetan Plateau. Results indicate that the dominant magnetic mineral is magnetite, and its concentration has grown significantly since the 1980s, which coincides with trends in climate warming of the Tibetan Plateau. Influenced by regional warming, the glacial recession around Nojingkangsang shortens the distance between the dust source and glacial areas and thus increases the concentration of coarse-grained magnetic minerals in ice cores. However, the frequency of dust storms, associated with annual precipitation, could play only a regulatory role on the magnetic content over yearly (or seasonal) time scales. Therefore, using a new approach, the magnetic index of insoluble microparticles in ice cores of this region is seen as mainly reflecting trends in climate warming. [ABSTRACT FROM AUTHOR]