Climatic controls on winter water vapor stable isotopes at Lhasa, Southern Tibetan Plateau

Abstract:

Water stable isotopes from Tibetan ice cores provide important climate information. However, the archived climate signal is an integrated signal of precipitation processes and post-deposition processes. Only very limited datasets of direct Tibetan precipitation and snowfall measurements are available so far. The isotopic composition of atmospheric water vapor traces directly the key physical processes of hydrological cycle, providing the potential of enhancing our knowledge of the climatic explanation from Tibetan ice cores. Thus, Continuous, in situ measurements of water vapor stable isotopes have been conducted at Lhasa, southern Tibetan Plateau, since October 2014, using an integrated cavity output spectroscopy analyser (LGR analyser) and a LGR water isotope standard source (WVISS) to calibrate and drift-correct the outputs. Combined with local meteorological data, TES data and simulations from the LMDZiso model, the climate controls of water vapor at Lhasa are explored at daily and seasonal scales.