Seasonal Climatic Variations Inferred From Pollen in a Laminated Glacier in the Southeastern Tibetan Plateau

A new, seasonal, laminated ice core pollen record spanning the last 13 years (2000-2012) from Zuoqiupu Glacier (5,600 m a.s.l.), located on the southeastern Tibetan Plateau (TP), reveals clear variations in pollen concentration and assemblage. A total of 117 continuous ice core layers were used for pollen analysis. Samples with high concentrations of Pinus and Tsuga could be identified as layers accumulated in spring, samples with high concentrations of Alnus and Artemisia could be identified as layers accumulated in autumn, and samples rich in herbaceous plant pollen could be regarded as layers deposited in summer. Three peaks of Tsuga pollen concentration accompanied by high Pinus content occurred in the spring of 2003, 2007, and 2010, which corresponded to wetter and warmer conditions modulated by the El Nino decaying phase (April-May in 2003, 2007, and 2010). Thus, pollen grains deposited on the Zuoqiupu Glacier can be used to study the impacts of atmospheric circulations on seasonal climate change over the southeastern TP.