Aerial observations of floe size distribution in the marginal ice zone of summer Prydz Bay
Aerial observations of floe size distribution in the marginal ice zone of summer Prydz Bay
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夏季普里兹湾边缘冰区浮冰尺寸分布的航空观测
DOI：
10.1029/2006jc003965
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发表时间：
2008-02
影响因子：
3.6
通讯作者：
Z J Li
中科院分区：
文献类型：
--
作者：
Z H Zhang;X L Dong;P Lu;Z J Li
基于2004年12月至2005年2月中国第21次南极科考队在Prydz湾边缘冰区（MIZ）拍摄的海冰航空照片，采用图像处理技术，对覆盖整个MIZ的两个合并样带进行了海冰几何参数提取。然后得到这些参数随进入MIZ距离的变化。不同的浮冰尺寸参数，即面积、周长和平均卡尺直径（MCD），随着与公海的距离的增加，经历了三个相似的阶段，即增加、平缓和再次增加。然而，流体形状参数（圆度和周长与MCD之比）的变化不如流体大小的变化显著。然后，为了修正累积粒径分布与理想幂律的偏差，采用上截断幂律函数和威布尔函数，并发现上述函数的四个计算参数是MIZ内粒径分布演变的重要描述符。其中，上截断幂律函数Lrof表示流体粒径的上限，大致等于每个正方形样本区域的最大粒径。在威布尔分布中，较大的浮冰在远离公海的正方形中所占的比例越来越大，大致等于平均浮冰大小。上面截断的幂律函数与冰破碎时的约束程度密切相关。随着进入MIZ距离的增加，其减小表明由于波的衰减，对浮体的约束条件减弱。威布尔分布的γ表示数据集中的均匀度。随着进入MIZ的距离增大，粒径分布也随之减小。最后，进行了浮冰粒径的统计检验，将整个MIZ划分为三个不同特征的浮冰区。这种带状结构的浮冰尺寸也与浮冰形状和粒径分布的趋势相吻合，被认为是MIZ中波浪-冰相互作用的直接结果。
On the basis of aerial photographs of sea ice floes in the marginal ice zone (MIZ) of Prydz Bay acquired from December 2004 to February 2005 during the 21st Chinese National Antarctic Research Expedition, image processing techniques are employed to extract some geometric parameters of floes from two merged transects covering the whole MIZ. Variations of these parameters with the distance into the MIZ are then obtained. Different parameters of floe size, namely area, perimeter, and mean caliper diameter (MCD), follow three similar stages of increasing, flat and increasing again, with distance from the open ocean. Floe shape parameters (roundness and the ratio of perimeter to MCD), however, have less significant variations than that of floe size. Then, to modify the deviation of the cumulative floe size distribution from the ideal power law, an upper truncated power‐law function and a Weibull function are used, and four calculated parameters of the above functions are found to be important descriptors of the evolution of floe size distribution in the MIZ. Among them,Lrof the upper truncated power‐law function indicates the upper limit of floe size and roughly equals the maximum floe size in each square sample area.L0in the Weibull distribution shows an increasing proportion of larger floes in squares farther from the open ocean and roughly equals the mean floe size.Din the upper truncated power‐law function is closely associated with the degree of confinement during ice breakup. Its decrease with the distance into MIZ indicates the weakening of confinement conditions on floes owing to wave attenuation. Theγof the Weibull distribution characterizes the degree of homogeneity in a data set. It also decreases with distance into MIZ, implying that floe size distributes increase in range. Finally, a statistical test on floe size is performed to divide the whole MIZ into three distinct zones made up of floes of quite different characteristics. This zonal structure of floe size also agrees well with the trends of floe shape and floe size distribution, and is believed to be a straightforward result of wave‐ice interaction in the MIZ.
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影响因子：
2
作者：
Burroughs, SM;Tebbens, SF
通讯作者：
Tebbens, SF
影响因子：
--
作者：
D. Rothrock;A. Thorndike
通讯作者：
D. Rothrock;A. Thorndike
影响因子：
2.4
作者：
C. Linton;Hyuck Chung
通讯作者：
C. Linton;Hyuck Chung
影响因子：
4.1
作者：
D. Sodhi
通讯作者：
D. Sodhi
DOI：
--
发表时间：
1951
期刊：
Journal of Applied Mechanics
影响因子：
--
作者：
W. Weibull
通讯作者：
W. Weibull