On the surface roughness characteristics of the land fast sea-ice in the Bohai Sea  

作　　者：LIU Chengyu CHAO Jinlong GU Wei LI Lantao XU Yingjun 

机构地区：[1]State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University [2]Shanghai Institute of Technical Physics, Chinese Academy of Sciences [3]Academy of Ministry of Civil Affairs and Ministry of Education for Disaster Reduction and Emergency Management, Beijing Normal University

出　　处：《Acta Oceanologica Sinica》2014年第7期97-106,共10页海洋学报（英文版）

基　　金：The National High Technology Research and Development Program of China under contract No.2011AA100505;the National Key Technology R&D Program of China under contract No.2006BAB03A03;the State Key Laboratory of Earth Surface Processes and Resource Ecology,Beijing Normal University of China under contract Nos 2010-TD-02 and 2011-TDZD-050

摘　　要：The surface roughness characteristics （e.g., height and slope） of sea ice are critical for determining the parameters of an electromagnetic scattering, a surface emission and a surface drag coefficients. It is also important in identifying various ice types, retrieval ice thickness, surface temperature and drag coefficients from remote sensing data. The point clouds （a set of points which are usually defined by X, Y, and Z coordinates that represents the external surface of an object on earth） of land fast ice in five in situ sites in the eastern coast Bohai Sea were measured using a laser scanner-Trimble GX during 2011-2012 winter season. Two hundred and fifty profiles selected from the point clouds of different samples have been used to calcu- late the height root mean square, height skewness, height kurtosis, slope root mean square, slope skewness and slope kurtosis of them. The root mean square of the height, the root mean square of the slope and the correlation length are about 0.090, 0.075 and 11.74 m, respectively. The heights of 150 profiles in three sites manifest the Gaussian distribution and the slopes of total 250 profiles distributed exponentially. In addition, the fractal dimension and power spectral density profiles were calculated. The results show that the fractal dimension of land fast ice in the Bohai Sea is about 1.132. The power spectral densities of 250 profiles can be expressed through an exponential autocorrelation function.The surface roughness characteristics （e.g., height and slope） of sea ice are critical for determining the parameters of an electromagnetic scattering, a surface emission and a surface drag coefficients. It is also important in identifying various ice types, retrieval ice thickness, surface temperature and drag coefficients from remote sensing data. The point clouds （a set of points which are usually defined by X, Y, and Z coordinates that represents the external surface of an object on earth） of land fast ice in five in situ sites in the eastern coast Bohai Sea were measured using a laser scanner-Trimble GX during 2011-2012 winter season. Two hundred and fifty profiles selected from the point clouds of different samples have been used to calcu- late the height root mean square, height skewness, height kurtosis, slope root mean square, slope skewness and slope kurtosis of them. The root mean square of the height, the root mean square of the slope and the correlation length are about 0.090, 0.075 and 11.74 m, respectively. The heights of 150 profiles in three sites manifest the Gaussian distribution and the slopes of total 250 profiles distributed exponentially. In addition, the fractal dimension and power spectral density profiles were calculated. The results show that the fractal dimension of land fast ice in the Bohai Sea is about 1.132. The power spectral densities of 250 profiles can be expressed through an exponential autocorrelation function.

关 键 词：sea ice ROUGHNESS statistical parameters fractal dimension spectral density 

分 类 号：P731.15[天文地球—海洋科学]