摘要
The environmental significance of levoglucosan(LEV) records in Tibetan glacier ice layers on sub-annual to annual scales, in particular their suitability as a specific biomarker for indicating past fire changes, is poorly understood at present. In this work, a continuous LEV record was reconstructed in a central Tibetan ice core for the period 1990–2012. The LEV record was classified into two categories based on its LEV concentrations: background levels and extreme events. Annually-resolved LEV records and background levels in the ice core were strongly correlated with satellite observations of fire occurrence frequency over the northern Indian peninsula between 2003 and 2012, especially for strong fire events during the pre-monsoon season(March–May). In addition, peaks in LEV concentrations may represent extreme fire events in regions around the Tibetan Plateau. LEV records in the ice core reflect a longterm increasing trend in fire background and also an increase in fire extreme events, across the Tibetan Plateau and its surroundings. We therefore conclude that LEV records in Tibetan ice cores can be used as a powerful tool for calibrating and reconstructing past fire changes over subtropical Asia.
The environmental significance of levoglucosan(LEV) records in Tibetan glacier ice layers on sub-annual to annual scales, in particular their suitability as a specific biomarker for indicating past fire changes, is poorly understood at present. In this work, a continuous LEV record was reconstructed in a central Tibetan ice core for the period 1990–2012. The LEV record was classified into two categories based on its LEV concentrations: background levels and extreme events. Annually-resolved LEV records and background levels in the ice core were strongly correlated with satellite observations of fire occurrence frequency over the northern Indian peninsula between 2003 and 2012, especially for strong fire events during the pre-monsoon season(March–May). In addition, peaks in LEV concentrations may represent extreme fire events in regions around the Tibetan Plateau. LEV records in the ice core reflect a longterm increasing trend in fire background and also an increase in fire extreme events, across the Tibetan Plateau and its surroundings. We therefore conclude that LEV records in Tibetan ice cores can be used as a powerful tool for calibrating and reconstructing past fire changes over subtropical Asia.
基金
supported by the Strategic Priority Research Program of Chinese Academy of Sciences(XDA20100000)
the National Natural Science Foundation of China(41701078,41805127)
International Partnership Program of Chinese Academy of Sciences(GJHZ1674)
the Second Comprehensive Scientific Expedition on Tibetan Plateau
