Research opportunities for combining climate models with moisture tracking

Global warming as well as human modification of the Earth’s surface profoundly affects the water cycle in regional climates. A key question for ecosystem health and humanity in general is how exactly water resources and water-induced hazards will be affected. Atmospheric moisture tracking methods have the potential to help unravel the mechanisms of changes in precipitation patterns.

In the climate we had around the year 2000, moisture tracking tools have shown that about 40% of the rainfall on land originated from the land itself and 60% was supplied by the oceans. Several studies have also indicated that due to the land being water-limited for evaporation, the relative importance of the oceans will increase in a warming climate. For more detailed moisture tracking studies into past and future climates, however, the provided data from climate model intercomparison projects is often a limiting factor.

In this presentation, we present a position paper that aims to unlock the potential of addressing novel research questions by combining climate modelling and moisture tracking. First, we review the state-of-the-art regarding moisture tracking with climate models. Second, we present the data requirements for moisture tracking models, which typically consist of a limited set of surface and atmospheric variables, but have specific requirements regarding temporal, horizontal and vertical resolution. Third, we evaluate typical uncertainties in moisture tracking that may arise from working with suboptimal resolutions. Fourth, we analyze to what extent some climate models are already providing sufficient data to perform moisture tracking studies. data request. Fifth, we map potentially interesting research avenues linked to specific Model Intercomparison Projects (MIPs) within the ongoing CMIP6 to illustrate how more synergies could be created.

In conclusion, we systematically evaluated the current research interest, limitations and potential for moisture tracking studies with climate model output. With this presentation we hope to stimulate CMIP7 and other climate data providers to work together with the moisture tracking community to align the supply and demand side of climate variables. Doing so, would allow us to tap the now largely untapped potential of using moisture tracking to gain more insight into past and future water cycle changes.