<p>Simulating sea-ice drift and deformation in the Arctic Ocean is still a challenge becaus... more <p>Simulating sea-ice drift and deformation in the Arctic Ocean is still a challenge because of the multi-scale interaction of sea-ice floes that compose the Arctic sea ice cover.&#160;The Sea Ice Rheology Experiment (SIREx) is a model intercomparison project formed within the Forum of Arctic Modeling and Observational Synthesis (FAMOS) to collect and design skill metrics to evaluate different recently suggested approaches for modeling linear kinematic features (LKFs) and provide guidance for modeling small-scale deformation.&#160;In this contribution, spatial and temporal properties of LKFs are assessed in 33 simulations of state-of-the-art sea ice models (VP/EVP,EAP, and MEB) and compared to deformation features derived from RADARSAT Geophysical Processor System (RGPS).<br>All simulations produce LKFs, but only very few models realistically simulate at least some statistics of LKF properties such as densities, lengths, lifetimes, or growth rates.&#160;All SIREx models overestimate the angle of fracture between conjugate pairs of LKFs pointing to inaccurate model physics. The temporal and spatial resolution of a simulation and the spatial resolution of atmospheric forcing affect simulated LKFs as much as the model's sea ice rheology and numerics.&#160;Only in very high resolution simulations (&#8804;2km) the concentration and thickness anomalies along LKFs are large enough to affect air-ice-ocean interaction processes.</p>
Year-round observations of the physical snow and ice properties and processes that govern the ice... more Year-round observations of the physical snow and ice properties and processes that govern the ice pack evolution and its interaction with the atmosphere and the ocean were conducted during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition of the research vessel Polarstern in the Arctic Ocean from October 2019 to September 2020. This work was embedded into the interdisciplinary design of the 5 MOSAiC teams, studying the atmosphere, the sea ice, the ocean, the ecosystem, and biogeochemical processes. The overall aim of the snow and sea ice observations during MOSAiC was to characterize the physical properties of the snow and ice cover comprehensively in the central Arctic over an entire annual cycle. This objective was achieved by detailed observations of physical properties and of energy and mass balance of snow and ice. By studying snow and sea ice dynamics over nested spatial scales from centimeters to tens of kilometers, the variability...
A coupled atmosphere - ocean - sea ice - land regional Arctic climate model (RACM) has recently b... more A coupled atmosphere - ocean - sea ice - land regional Arctic climate model (RACM) has recently been developed. The atmospheric model used in RACM is the Weather Research and Forecasting (WRF) model. The ocean and sea ice models are the same as those used in the NCAR Community Climate System Model (CCSM3), although used on a regional domain, and are the Los Alamos National Laboratory POP ocean model and CICE sea model. Land surface processes and hydrology are represented by the Variable Infiltration Capacity (VIC) model. These four climate system component models are coupled using the NCAR CCSM coupler CPL7. Initial results from this model will be presented that emphasize the model's ability to simulate the full annual cycle of atmosphere and land state. Results from a ten-year (1989-1999) RACM simulation will be presented and compared with uncoupled WRF-only simulations. The comparison will highlight differences between the atmosphere-land and fully coupled simulations. Future ...
<p>Simulating sea-ice drift and deformation in the Arctic Ocean is still a challenge becaus... more <p>Simulating sea-ice drift and deformation in the Arctic Ocean is still a challenge because of the multi-scale interaction of sea-ice floes that compose the Arctic sea ice cover.&#160;The Sea Ice Rheology Experiment (SIREx) is a model intercomparison project formed within the Forum of Arctic Modeling and Observational Synthesis (FAMOS) to collect and design skill metrics to evaluate different recently suggested approaches for modeling linear kinematic features (LKFs) and provide guidance for modeling small-scale deformation.&#160;In this contribution, spatial and temporal properties of LKFs are assessed in 33 simulations of state-of-the-art sea ice models (VP/EVP,EAP, and MEB) and compared to deformation features derived from RADARSAT Geophysical Processor System (RGPS).<br>All simulations produce LKFs, but only very few models realistically simulate at least some statistics of LKF properties such as densities, lengths, lifetimes, or growth rates.&#160;All SIREx models overestimate the angle of fracture between conjugate pairs of LKFs pointing to inaccurate model physics. The temporal and spatial resolution of a simulation and the spatial resolution of atmospheric forcing affect simulated LKFs as much as the model's sea ice rheology and numerics.&#160;Only in very high resolution simulations (&#8804;2km) the concentration and thickness anomalies along LKFs are large enough to affect air-ice-ocean interaction processes.</p>
Year-round observations of the physical snow and ice properties and processes that govern the ice... more Year-round observations of the physical snow and ice properties and processes that govern the ice pack evolution and its interaction with the atmosphere and the ocean were conducted during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition of the research vessel Polarstern in the Arctic Ocean from October 2019 to September 2020. This work was embedded into the interdisciplinary design of the 5 MOSAiC teams, studying the atmosphere, the sea ice, the ocean, the ecosystem, and biogeochemical processes. The overall aim of the snow and sea ice observations during MOSAiC was to characterize the physical properties of the snow and ice cover comprehensively in the central Arctic over an entire annual cycle. This objective was achieved by detailed observations of physical properties and of energy and mass balance of snow and ice. By studying snow and sea ice dynamics over nested spatial scales from centimeters to tens of kilometers, the variability...
A coupled atmosphere - ocean - sea ice - land regional Arctic climate model (RACM) has recently b... more A coupled atmosphere - ocean - sea ice - land regional Arctic climate model (RACM) has recently been developed. The atmospheric model used in RACM is the Weather Research and Forecasting (WRF) model. The ocean and sea ice models are the same as those used in the NCAR Community Climate System Model (CCSM3), although used on a regional domain, and are the Los Alamos National Laboratory POP ocean model and CICE sea model. Land surface processes and hydrology are represented by the Variable Infiltration Capacity (VIC) model. These four climate system component models are coupled using the NCAR CCSM coupler CPL7. Initial results from this model will be presented that emphasize the model's ability to simulate the full annual cycle of atmosphere and land state. Results from a ten-year (1989-1999) RACM simulation will be presented and compared with uncoupled WRF-only simulations. The comparison will highlight differences between the atmosphere-land and fully coupled simulations. Future ...
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