Climatology

Quaternary Tipping Points of Lake Systems in the Arid Zone of Central Asia (Q-TiP)

Project researchers

 - Completed project -

The research project Quaternary Tipping Points (Q-TiP) of Lake Systems in the Arid Zone of Central Asia was part of the CAME II program, funded by the German Federal Ministry of Education and Research (BMBF). The Qaidam Basin (QB) is an endorheic, intermontane basin located in the Northeast of the Tibetan Plateau. While the lower part of the QB has a hyperarid climate today, paleographic studies show it was a freshwater mega-lake system during the middle Pliocene (ca. 3.3-3.0 Ma BP). Although the surrounding areas continued to dry up in this series, the lake remained for a long time. It was not until the beginning of the Pleistocene, about 2.6 Ma BP, that the lake began to shrink and finally almost disappeared. The question of how the mega lake system could resist the regional trend of continuous aridification for so long has not been conclusively answered scientifically to this day.

The existence of a mega-lake system during the Pliocene implies that the long-term water balance of the QB catchment must have been balanced or positive on average. If this had not been the case, the lake would have dried up in the meantime, leaving layers of evaporite rocks.

Research

This research project addresses how the long-term mean annual water balance in the QB could have been zero or even positive over the entire period under a very dry climate so that a mega lake system could have been sustained. We examine the sensitivity of the water balance to changing temperatures and specific humidity. It provides a first estimate of the water balance under different climatic conditions, such as the mid-Pliocene or the future. We are also comparing models of atmospheric conditions from today and the middle Pliocene to assess differences in QB water balance and atmospheric water transport in Central Asia and to determine the large-scale control mechanisms that regulate these differences. This research is based on the state-of-the-art Weather Research and Forecasting (WRF-ARW) modeling system and is conducted in close collaboration with the University of Tübingen, Germany.

Since the mid-Pliocene is often considered an analog for modern climate change, our studies intend to provide a sound basis for evaluating environmental changes that may be caused by projected future climate changes in this region.

Prof. Dr.

Dieter Scherer

Office AB 3

Benjamin Schmidt

Office AB 3