Model Intercomparison and Improvement Project (MIIP)
To improve the capabilities of environmental prediction models in polar regions it is necessary to increase our understanding – and model representation – of the complex processes and interactions in the coupled atmosphere-ocean-sea ice-land system. The YOPP Model Intercomparison and Improvement Project (MIIP) has coordinated the activities to improve process representation, involving observational groups and modellers, including scientists from operational forecast centres.
An important element of MIIP is the MOSAiC Near Realtime Verification (NRV) Project (see details in the sea-ice section), which is focused on evaluating the simulation of the Arctic atmospheric boundary layer and surface energy budget in short-term forecasts of the coupled ocean-atmosphere-sea ice system from state-of-the-art operational and experimental forecast systems using observations taken during the MOSAiC campaign.
Much of the progress on process representation resulted from coordinated efforts during a few specific time periods: the two Northern Hemisphere Special Observing Periods (SOPs), and the MOSAiC year (October 2019 to October 2020) that included the YOPP Targeted Observing Period (TOP) (mid-April 2020).
Another important aspect underpinning success was the focus on several ‘supersite observatories’ – well instrumented locations on land or at sea with sustained observations that were matched by corresponding high-resolution, high-frequency model output (see the YOPPsiteMIP activities). This included novel model experimentation, for example with coupled single column models.
Parameterisation of physical processes that have seen substantial improvements during YOPP include the representation of snow on land and over sea, and surface-atmosphere exchange over sea ice.
This work is being led by Prof Gunilla Svensson from Stockholm University.
Arduini, G., and co-authors, (2019): Impact of a multi-layer snow scheme on near-surface weather forecasts. J. Adv. Model. Earth Syst., 11, 4687-4710.
Batrak, Y., Müller, M., (2019): On the warm bias in atmospheric reanalyses induced by the missing snow over Arctic sea-ice. Nat Comm 10, 4170.
Elvidge, A. D., and co-authors, (2021): Surface heat and moisture exchange in the marginal ice zone: Observations and a new parameterization scheme for weather and climate models, J. Geophy. Res.: Atmospheres, 126.
Hartung, K. and co-authors, (2022): Exploring the dynamics of an Arctic sea ice melt event using a coupled Atmosphere-Ocean Single-Column Model, J. Adv. Model. Earth Syst., 14(6).
Tjernström, M., and co-authors, (2020): Central Arctic Weather Forecasting: Confronting the ECMWF IFS with observations from the Arctic Ocean 2018 expedition. Quart. J. Roy. Meteor. Soc., 147,1278-1299