Understanding the modes of the sea-ice thickness distribution: Processes and variability

海冰厚度分布(ITD)是了解北冰洋热量、质量和淡水收支的基础，在气候反馈中起着重要作用，对区域初级生产力、海洋航行和海面作业具有很强的控制作用。根据常年冰带(PIZ)的观测估计的ITD几乎总是在某些厚度上显示出一个突出的模式，嗯，比与年度冻结和最近打开的导线相关的模式厚度大并且与之不同。这种模式被解释为多年未变形的冰在其平衡厚度下，或在热力学上向其平衡厚度增长。观测表明，在PIZ内，Hm在大约1至5米的范围内存在显著的区域间、年度和年际变化。与脊冰的平均值、标准差和e折叠长度尺度等其他参数相比，ITD的这一统计数据受到的关注要少得多。该项目的结果将提高对这一具有重要生态和社会意义的冰厚度测量的时空变化的理解。PI假设，与其他冰厚度测量相比，近模式冰厚度的测量具有较小的偏差和随机误差，从而使该模式成为ITD的稳健参数。拟议研究的目的是通过改进对ITD时空变化的估计，并更好地了解其在北极气候中的作用，从而加强对ITD的了解，重点放在Hm模式上。具体目标是：(A)检验该模式对观测误差具有稳健性的假设；(B)记录PIZ中Hm和ITD的其他参数的空间和时间变化；(C)模拟ITD和Hm的变化，作为对规定的强迫的响应，并将结果与观测结果进行比较；(D)研究模拟的ITD对脊线形成和强迫数据中的误差的依赖性；以及(E)综合结果，作为对强调Hm及其变化的ITD的新的分析和解释。研究领域是1975-2010年期间的北冰洋PIZ。要考虑的时间尺度包括季节间、年度间和趋势，以及作用于小时和更长时间的物理过程。

The sea-ice thickness distribution (ITD) is fundamental to understanding the heat, mass and freshwater budgets of the Arctic Ocean, plays important roles in climate feedbacks, and exerts strong control on regional primary productivity, marine navigation and surface operations. Estimates of ITD based on observations in the perennial ice zone (PIZ) nearly always exhibit a prominent mode at some thickness, hm, larger than and distinct from modal thicknesses associated with the annual freezeup and recently-opened leads. This mode has been interpreted as un-deformed multi-year ice at, or growing thermodynamically towards, its equilibrium thickness. Observations indicate significant inter-regional, annual and inter-annual variations of hm within the PIZ, over the approximate range 1 to 5 meters. This statistic of the ITD has received much less attention than other parameters, such as the mean, standard deviation and e-folding length scale of ridged ice. The results of this project will improve understanding of the variations in space and time of this ecologically and societally important measure of ice thickness.The PI hypothesizes that measurements of ice of near-modal thickness have reduced bias and random error with respect to other measures of ice thickness, thus making the mode a robust parameter of the ITD. The goal of the proposed research is to enhance understanding of the ITD, focusing on the mode hm, by producing improved estimates of space/ time variations of the ITD, and greater understanding of its role in Arctic climate. Specific objectives are (a) to test the hypothesis that the mode is robust to observational errors; (b) to document space and time variation of hm and other parameters of the ITD in the PIZ; (c) to simulate the variations of the ITD and hm as a response to prescribed forcing and compare results with observations; (d) to study the dependence of simulated ITDs on the formulation of ridging and on errors in the forcing data; and (e) to synthesize the results as a new analysis and interpretation of the ITD emphasizing hm and its variations. The study domain is the Arctic Ocean PIZ during the period 1975-2010. The timescales to be considered include inter-seasonal, inter-annual and trends, as well as physical processes acting on hours and longer.