Application of fluid mechanical technique to the analysis of ice movements in Okhotsuk Sea using satellite millimeter radar images

流体力学技术在卫星毫米雷达图像分析鄂霍楚克海冰运动中的应用

• 批准号: 13650163
• 负责人: HANIU Hiroyuki
• 金额: $ 1.6万
• 依托单位: Kitami Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13650163/
• 关键词: Sea ice; Satellite millimeter radar image; Okhotsuk Sea; Saghalien; Image processing; Image correlation method; Prevention of sea disaster

Sea ice movements in Okhotsuk Sea were investigated based on millimeter radar images obtained by SSM/I sensors on board DMSP satellite by means of image correlation PIV method. Due to the thick clouds covering the Okhotsuk Sea in winter, investigation of ice via visible light is difficult, but the millimeter radar images can see through the thick clouds and enable us the investigation. 37GHz and 85GHz radar images were obtained from National Snow and Ice Data Center in U.S.A. Then in order to obtain clear images, pinhole noises were eliminated followed by smoothing and elimination of cloud's images on open sea. Using these clear images, ice movement in the past several years were investigated to differentiate the characteristics between years of more sea ice and less sea ice. Then movements of ice in the inner region of ice field and the perimeter were compared by means of correlation PIV to estimate the region of ice production. Also prior to PIV analysis, conditions such as the shape of analyzing matrix were considered, and traceability of present PIV method is compared with tracking results of GPS beacon conducted 1994 to ensure the reliability of present PIV method. As the results, 1) strength of north-westerly seasonal wind was found to determine the amount of sea ice in each year, 2) sea ice was found to form vortex like structure near Hokkaido in every year, 3) ice field near Russian east coast was found to detach from the coast to create open sea region by strong and extremely cold seasonal north-westerly wind, and immediately the sea surface is frozen to create new sea ice.

利用DMSP卫星搭载的SSM/I传感器获得的毫米波雷达图像，采用图像相关PIV方法对鄂霍次克海海冰运动进行了研究。由于冬季鄂霍次海被厚厚的云层覆盖，通过可见光进行冰的调查是困难的，但毫米雷达图像可以穿透厚厚的云层，使我们能够进行调查。利用美国国家冰雪数据中心的37 GHz和85 GHz雷达图像，对远海云图进行针孔噪声消除、平滑和消云处理，得到清晰的图像。利用这些清晰的图像，研究了过去几年的冰运动，以区分海冰多和海冰少的年份之间的特征。然后利用相关PIV技术对冰场内部和外围冰的运动进行比较，从而确定冰场的产冰区域。在进行PIV分析之前，还考虑了分析矩阵的形状等条件，并与1994年进行的GPS信标跟踪结果进行了溯源性比较，以确保PIV方法的可靠性。结果表明：（1）西北季节风的强弱决定着每年海冰的数量;（2）每年在北海道附近海冰都形成涡旋状结构;（3）在强而极冷的季节西北风的作用下，俄罗斯东海岸附近的冰原脱离海岸，形成开阔海区;海面立即被冻结形成新的海冰。