Collaborative Research: Detailed Investigation of the Dynamic Component of Sea Ice Mass Balance

Hutchings -0612527 Geiger-0611991 Kambhamettu-0612105一项包括野外工作、遥感分析和模拟的活动被提议调查海冰运动的机制，特别是冰缘的打开和闭合形成脊，有助于北极冰盖的质量平衡。 实地行动计划在2007年春季进行，为期两个月，利用计划中的美国海军冰上营地。 季节和营地的位置发生时，这种动态组件占主导地位的冰盖，是接近其最大的年平均厚度的质量平衡。收集到的数据将用于直接验证模型参数化的应力和应变率之间的关系，在冰包和冰质量的机械重新分布。 PI将测试全球气候模型（GCM）中常用的模型配置，为GCM社区提供直接估计，这些模型如何准确地再现冰厚分布的脊和动力热力学控制。 将进行一系列模型试验，以估计海冰质量对模型参数和变量的敏感性。 对这一模型输出、观测和传感器相互比较的综合分析将有助于确定关键的监测要求，以补充模型的不确定性。 这项研究的结果将有助于更好地了解造成北极海冰变化的过程，增强这种过程的模型，从而改进对气候系统重要方面的轨迹的预测，例如最近观察到的北冰洋夏季海冰范围的减少。

Hutchings - 0612527Geiger - 0611991Kambhamettu - 0612105A 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.