Detection Of Ice And Snow Thickness And Thermodynamic Parameter Analysis In The Prydz Bay,East Antarctica

Climate change now is a serious problem.The Antarctic region is sensitive to global climate change,so the research on the Antarctic region,especially the Antarctic sea ice change,is playing a significance role to the research on the global climate change.The Antarctic sea ice research now is mainly based on two aspects: the research on the Antarctic sea ice distribution range and the research on the thickness change of the fixed ice.Observing the extent of sea ice distribution mainly depends on satellites,while observing the formation or melting of sea ice mainly depends on artificial.Due to the bad conditions in the Antarctic region,it is difficult to observe manually for a long time.Therefore,it is necessary to design an automatic ice thickness detection device that can adapt to the severe climatic conditions in the Antarctic region.Aiming at the continuous automatic detection of Antarctic sea ice thickness and snow cover depth,this paper designed a snow and ice environment detection system based on the air,snow cover and ice sheet temperature gradient characteristics.This system can continuously and automatically monitor the parameters such as snow and ice condition in the Antarctic.the research contents and results as follow:(1)The types,formation process and basic physical characteristics of sea ice are summarized and analyzed by consulting literature.According to the temperature characteristics of sea ice and snow cover,an automatic ice and snow detection system is designed,which can automatically detect the thickness and depth of Antarctic sea ice.(2)This paper cooperates with the National Marine Environment Forecast Center.A1,A2 and A3 sets of ice and snow detection sensors and systems were installed in the Prydz Bay,East Antarctica.The sensors collect data every hour and acquire real-time temperature data of the measured air,snow,sea ice and sea water profile.By analyzing the temperature profiles of different approaches,the difference of temperature variation of sea ice and snow under the influence of temperature can be reflected effectively,that is,the difference of heat conduction characteristics of air,snow,sea ice and sea water.By searching for a reasonable temperature threshold,MATLAB program is used to judge the position of the upper and lower interface of snow and sea ice automatically,and the variation process of sea ice thickness and snow depth during the whole observation period is obtained.The results show that from the installation time of sensors,sea ice continued to grow,and the growth rate of sea ice slowed down in October until the maximum thickness of sea ice reached 170 cm at the end of October.The average errors between the ice thickness values collected by A1,A2 and A3 sensors and the observed values are 5.1 cm(A1),3.4 cm(A2),3.6 cm(A3),and the average errors of snow depth are 3.2 cm(A1),3.5 cm(A2)and 2.7 cm(A3)respectively.The measured thickness by sensors can better reflect the evolution of ice and snow conditions.It is an effective method for detecting the ice and snow environment in a harsh climate.(3)The freezing process of sea ice is mainly affected by temperature,and the sea ice temperature will change by air temperature,but the volatility decreases with the increase of sea ice thickness.When the sea ice is thicker,the bottom has a certain hysteresis with the change of temperature,and the thicker the sea ice is,the more obvious the hysteresis is.In addition,the snow cover can also react the sea ice insulation.The surface temperature of sea ice is basically the same as the air temperature when there is no snow cover.But when there is thick snow cover on the sea ice surface,the influence of its temperature decreases.(4)In this paper,we calculated the conductive heat flux at the ice top and bottom with the temperature gradient method according to the variation of temperature and thickness of sea ice.At the same time,we established the heat energy balance relation at the ice bottom with the residual method and calculated the water heat flux at ice bottom.The water heat flux at ice bottom was controlled by the conductive heat flux and latent heat flux at ice bottom.