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KLIMAFORSK-Stort program klima

Constraining future precipitation changes in Europe and the Arctic from historical observations of the atmospheric energy budget

Alternative title: Constraining future precipitation changes in Europe and the Arctic from historical observations of the atmospheric energy budget

Awarded: NOK 12.0 mill.

Project Number:

325270

Application Type:

Project Period:

2021 - 2027

Funding received from:

The recently published IPCC report (Sixth assessment report) linked increase in extreme weather to human activity. In some areas and seasons, there is particularly large uncertainty in future precipitation from climate model calculations. This includes future summer rainfall in northern Europe, where some models give a decrease in precipitation and other models an increase. This will also be important for the probability of more drought. Future increases in precipitation in the Arctic will have an impact on extreme precipitation of varying duration. Also in this area, there are large differences in climate model results. BUDGET will increase our understanding of the causes of why climate models have such large differences in future Arctic rainfall and summer precipitation in northern Europe. This is done by analyzing the atmospheric energy budget, which consists of atmospheric radiation cooling and heating as well as sensible heat from the surface to the atmosphere. In a previous study, we found that on a global scale in the climate models the reduction in sensible heat, which causes an increase in precipitation, is as large as the global precipitation change over the industrial period. This finding is reinforced by the latest climate model calculations featured in the most recent IPCC report within BUDGET. However, a compelling contrast emerges when these climate models are compared with data obtained from satellites and re-analyses. In contradiction to the models, these observational datasets indicate a global-scale increase in sensible heat, leading to a decline in precipitation. BUDGET will further examine the implications arising from these different trends in sensible heat for precipitation.

The hydrological cycle closely links the atmosphere, hydrosphere, biosphere and cryosphere on various timescales. Precipitation changes, including extreme precipitation changes, are likely to become one of the most important consequences of our changing climate over the coming decades. Precipitation is strongly linked to the energy budget in the atmosphere since the surface latent heat flux is a direct heat source for the atmosphere when water vapour condenses. BUDGET will apply the constraint of the atmospheric energy budget to improve quantification of future precipitation changes in Northern Europe and the Arctic by using the observed trends. BUDGET utilizes thereby the satellite era advancement and available satellite data to quantify trends in the atmospheric energy budget components. Re-analysis will complement the satellite data. We will apply this new scientific knowledge to weight climate model performance and thus constrain future regional precipitation changes. BUDGET will quantify causes of diversity in model simulated regional precipitation changes. We will quantify whether model discrepancies of historical and future precipitation changes are linked to different climate drivers, such as greenhouse gases and aerosols, or host model differences. BUDGET will investigate whether the constraints on the atmospheric energy budget have implications for changes in extreme precipitation. A main aim in BUDGET is to understand the physical processes causing model diversity using four different climate models allowing for the possibility of future model improvements.

Funding scheme:

KLIMAFORSK-Stort program klima