| Under the background of global warming,the Arctic sea ice thickness and range show a rapid decrease trend.The lateral melting in the ice-water interface will accelerate the reduction of sea ice.The study of lateral melting and its influencing factors will help to deepen the understanding of the ice melting mechanism and the process of Arctic sea ice reduction.In order to quantitatively explore the main factors that affect the lateral melting of the ice layer and simplify the parameterization scheme of the lateral melting rate of the ice layer,the melting process of pure water ice under the conditions of no wind,still water,no radiation and pure thermodynamics was simulated in the laboratory,the lateral melting amount of the ice layer was measured,and the laboratory air temperature,skin temperature,water temperature,ice temperature and other factors during melting were recorded.The observation results show that:(1)under the pure thermodynamic condition of no radiation,the ice layer melts uniformly in the lateral,and the melting rate of the upper and lower layers is faster than that of the middle layer.(2)The results of correlation analysis show that there is a good linear correlation between air temperature and water temperature,ice temperature and ice skin temperature.(3)Information flow results show that air temperature is the most important factor affecting the lateral melting of ice.(4)Finally,a parametric model between the lateral melting rate and the air temperature is established by fitting,and compared with the parameterized schemes of Josberger,Maykut and Steele.The standard deviations obtained in this paper and the previous parameterized schemes were 0.08mm/h,0.11mm/h,0.08mm/h,0.12mm/h,the results show that the parametric model simulation effect of this study is better,and the purpose of simplifying the parameters is achieved.Considering that the lateral melting of ice layer is affected by the geometry and size of the ice body,which is related to the perimeter of the sea ice,the author uses the sea ice SAR images of RADASAT-2 and uses Prewitt,Sobel,and Canny edge detection algorithms to calculate the perimeter of sea ice in the image range,and consider the impact of different image resolutions and different edge detection operators on the calculation results.The results show that:(1)different image resolutions resulting in the different edge detection results: For the image,Sobel edge detection operator is suitable when there are few small pieces of broken ice on the sea ice image,and the detection effect is best when the resolution is near 50 m.The ice-water boundary line is clear and the edge line is relatively complete;when there are many small ice fragments in the sea ice image,Canny edge detection operator is suitable,and the detection result is the best when the resolution is near 100 m.(2)For the calculation of sea ice perimeter,when there are few small pieces of broken ice on the sea ice image,the Prewitt operator and Sobel operator are suitable,and the calculation result is close to the artificial judgment result when the resolution is about 35 m ? 40m;When there are many small ice fragments in the sea ice image,Prewitt operator is suitable,and the calculation result is the closest to the result of manual judgment when the resolution is near 65 m and 155 m. |
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