Permafrost Landscapes in Transformation – from Local-Scale Processes to the Global Model NorESM

Permafrost is a highly dynamic element of the Cryosphere that is intimately meshed with the global climate system through complex interactions. A massive release of greenhouse gases from thawing organic-rich permafrost could constitute a significant additional warming potential, so that capturing permafrost thaw is among the key priorities for reducing uncertainty in future projections in Earth System Models (ESMs). PERMANOR will for the first time systematically investigate the representation of permafrost in the Norwegian Earth System Model NorESM by bringing together expertise in observations, process based modeling, model downscaling, and ESM development. PERMANOR will bring the highly dynamic evolution of permafrost landscapes in the focus of ESM development. Many observed forms of permafrost thaw, e.g. the development of thermokarst ponds or the disintegrations of subarctic peat plateaus, cannot be explained without lateral transport of energy, water and snow on spatial scales that are several orders of magnitude smaller than a typical ESM grid cell. To reconcile these different scales, the project will pioneer a two-stage concept by aiming for a statistical representation of small-scale processes, while WRF (Weather Research and Forecasting) modeling will facilitate upscaling of parameterizations to ESM scale. A strong focus will be laid on conceptualizing interactions between microtopography, ground ice content and snow depth, with the goal of developing a statistical representation of permafrost landscape evolution. As a spin-off, climate projections will be downscaled to 1km for key regions in N Scandinavia, Svalbard, and Siberia. Ultimately, PERMANOR will conceptualize process understanding from in-situ studies to develop new model algorithms and pursue their implementation in a coupled ESM framework. The improved representation of permafrost landscape dynamics in ESM will lead to reducing our uncertainty in the predictability of future climate change.