Search

Abstract: 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.

The tropical Asian regions are particularly prone to catastrophic droughts due to high temperature and evaporation and their sensitivity to variable oceanic‐atmospheric circulation. The extent to which future global warming may intensify droughts in this populous region is a matter of utmost concern. Palaeoclimatic data can help inform scientists learn more about the temporal patterns and drivers of monsoon change over geological timescales. In this paper, we present a new 8,200 year biomarker record preserved in the annually laminated sediments of Maar Lake Twintaung, Myanmar. The δ13C27‐35sedimentary record is mainly derived from leaf wax lipids in the lake catchment, which is presently dominated by C3vegetation in the modern lake catchment. The δ13C27‐35is mainly regulated by plant physiological and biochemical responses to drought stress and, as such, can be used as a proxy of past changes in moisture. The δ13C27–35record reveals distinct decadal‐to‐centennial‐scale droughts superimposed on a trend of gradually decreasing summer monsoon intensity from the mid‐Holocene to late Holocene. Within the limits of the dating uncertainties, these decadal‐to‐centennial‐scale droughts are found to be well correlated with the southward shift of the Intertropical Convergence Zone. It highlights thepimportance of the Intertropical Convergence Zone shift (tropical monsoon trough) in regulating monsoon rainfall in the region. In addition, most of the droughts are likely to be linked with active volcanism and solar minima and suggest a coupled process between external drivers and internal climate dynamics. Leaf wax n‐alkanes record in varved sediment of Maar lake Twintaung, MyanmarThe result indicates distinct decadal‐to‐centennial‐scale droughts over the past 8.2 kaThe drought cycles link with the ITCZ shift, solar and volcanic eruption