南极普里兹湾夏季海冰边缘区内破碎海冰的分布特征  

Floe size distribution characteristics in the summer marginal ice zone of Prydz bay,Antarctica

作　　者：卢鹏[1] 李志军[1] 张占海 董西路[3] 

机构地区：[1]大连理工大学海岸与近海工程国家重点实验室,辽宁大连116024 [2]国家极地研究中心,上海200129 [3]大连理工大学电子与信息工程学院,辽宁大连116024

出　　处：《水科学进展》2007年第6期884-892,共9页Advances in Water Science

基　　金：国家自然科学基金重点资助项目(40676001;40233032;40376006);科技基础性工作和社会公益研究资助专项(2003DEB5J057)~~

摘　　要：基于中国第21次南极考察中获得的69°00′S、76°24′E附近普里兹湾夏季海冰边缘区内破碎海冰的航拍照片,利用图像处理的方法从中提取了破碎海冰的若干几何参数,得到了海冰边缘区内随着与开阔水域距离增大,海冰面积、平均钳测直径等几何参数的变化规律。并按其尺寸的变化规律将海冰边缘区划分为边界区、过渡区和内部区三部分,其变化和波浪在冰边缘区中的衰减过程紧密相关。圆度的变化则说明海冰边缘区中海冰磨损最充分的地方是在冰间相互作用最明显的过渡区。另外,一种改进的幂函数分布和Weibull分布用来对破碎海冰尺寸的累积频率进行拟合,分布函数中各参数的变化情况很好的反映了海冰边缘区内破碎海冰的分布变化。其中,参数Lr随着与开阔水距离增加而增大(说明由于波能衰减导致可以出现的破碎海冰最大尺寸的增加);尺度参数L0随着与开阔水距离增加而增大(反映了破碎海冰平均尺寸的增加以及由于波能的衰减而导致单位面积区域内尺寸较大的破碎海冰所占比例的增加);分布维数D随着与开阔水距离增加而减小(说明了由于波能的衰减导致破碎海冰所受约束条件的减弱);形状参数γ随着与开阔水距离增加而减小(说明了随着波能的衰减破碎海冰尺寸分布范围的增大)。Based on the aerial photos of sea ice floes en during the 21st Chinese Antarctic Research Expedi in the marginal ice zone （MIZ） of Prydz bay near 69°00＇S,76°24＇E taktion （CHINARE2004）, the image processing techniques are employed to extract many geometric parameters of ice floes in the MIZ. The variations of floe size parameters, such as area and mean caliper diameter （MCD） with increasing distance to open water are obtained. And according to the variation trend, the whole MIZ is divided into three zones made up of floes of quite different characteristics ： edge zone, transition zone and internal zone. Such division is closely associated with the wave attenuation in the MIZ. The variation of floe roundness reveals that the floes in the transition zone receive most sufficient abrasion because of significant collisions in there. Moreover, an improved powerlaw function and a Weibull function fit the cumulative distribution of floe size, and the calculated parameters contained in the two functions give nice descriptions of the evolution of floe size distribution in the MIZ. The parameter Lr increases with the distance to open water, revealing the increase of max floe size with wave attenuation. Scale parameter L0 increases with the distance to open water, showing the increase of average floe size and the proportion of large floes. The distribution dimension D decreases with the distance to open water, displaying the weakening of confinement degree as ice breakup. Shape parameter γ decreases with the distance to open water, disclosing the widening range of floe size distribution.

关 键 词：南极 普里兹湾海 冰边缘区 破碎海冰 分布维 

分 类 号：P731.15[天文地球—海洋科学]