Identifying orbital- and sub-orbital-scale controls on the Asian summer monsoon: a 500,000 year hydroclimate record from Nam Co, Tibet [NamCore-UK]

The Tibetan Plateau, located north of the Himalaya mountain range, is a large geographical area with an elevation greater than 4 km above sea-level. It is called "The Third Pole" because it has the third highest glacier ice volume after the Arctic and Antarctic, and it is a region that is already experiencing the effects on the ongoing global climate crisis. The Tibetan Plateau and associated glacier ice also have great significance for many neighbouring Asian countries, being the source of many of the major river systems supplying water to 100s of millions of people, as well as sediment that builds several mega-deltas that are homes to 10s of millions of individuals. The Tibetan Plateau also plays a major role in the Indian summer monsoon atmospheric circulation system, with the Sun's heating of the high-altitude region traditionally thought to set up a low-pressure cell (i.e., upward flowing heated air), into which wetter air masses are drawn from the Indian Ocean, from which seasonal monsoonal rain then falls over the Indian sub-continent. However, there remains a lack of detailed understanding of the controls on, and the complexity of, Asian monsoon systems, and additional knowledge is required in relation to how climate in this region will develop under future climate-change scenarios that will result from ongoing global warming.

One way to gain an improved understanding of natural Earth systems, such as the Indian summer monsoon, is to investigate such systems in the historical and geological past, i.e. by the reconstruction of past climate (called palaeoclimate), one commonly used statement being "the past is the key to the present". To be able to investigate palaeoclimate it is necessary to have an archive of information and a means to reconstruct key palaeoclimate parameters, the latter termed a proxy-based approach because one measures something preserved in the archive (the proxy) that exhibits a relationship with the key parameter...