Geiger -0611991 Kambhamettu - 0612105
A campaign consisting of fieldwork, remote sensing analyses, and modelling is proposed to investigate the mechanisms whereby the motion of sea ice, in particular the opening of leads and their closing to form ridges, contribute to the mass balance of the arctic ice pack. The field campaign is proposed to occur over a 2-month period in spring 2007, taking advantage of the planned U.S. Navy ice camp. The season and location of the camp occur when and where this dynamic component dominates the mass balance of an ice cover that is nearing its maximum annual mean thickness. Data collected will be used to directly validate model parameterizations of the relationship between stress and strain rate within the ice pack and the mechanical redistribution of ice mass. The PIs will test model configurations commonly used in Global Climate Models (GCMs), to provide the GCM community with a direct estimate of how accurately such models reproduce the ridging and dynamic-thermodynamic control of the ice thickness distribution. A series of model runs will be performed to estimate sea ice mass sensitivity to model parameters and variables. Combined analysis of this model output, observations and sensor inter-comparisons will allow identification of key monitoring requirements to complement model uncertainties.
The results of this study will contribute to a better understanding of the processes contributing to variations in the arctic sea ice pack, enhancements to models of such processes, and consequent improved predictions of the trajectory of important aspects of the climate system, such as the recently observed reduction in summer sea ice extent in the Arctic Ocean.
