摘要
2006年对东南极中山站附近湖冰和固定冰的热力学过程进行了系统观测。基于观测数据比较湖冰和固定冰热力学生消过程;分析湖冰和固定冰温度对气温变化的响应规律;计算不同深度层湖冰和固定冰的垂向热传导通量。结果表明:观测的湖泊和海岸区均在2月底至3月初形成连续冰层;湖冰9月底至10月初达到最大冰厚,早于固定冰1—2个月,湖冰最大冰厚在156—177 cm之间,固定冰最大冰厚在167—174 cm之间;湖冰和固定冰温度相对气温变化均存在高频衰减和相对滞后,随着深度增大其高频衰减和相对滞后均有所增大,其中固定冰更为明显,这导致相同深度的海冰垂向热传导通量小于湖冰的相应值;融冰期,固定冰脱盐过程导致其融点温度有所升高,从而出现冰温高于当地海水冻结温度的现象。
Thermodynamic processes of lake ice in three lakes and landfast sea ice around Zhongshan Station,east Antarctica were investigated in 2006.The growth and decay processes of lake ice were compared with those of landfast sea ice on the basis of in situ data.The responses of lake-ice and landfast sea-ice temperatures at varying depths relative to the time series of the local surface air temperature were explored.The vertical conductive heat fluxes at varying depths of lake ice and sea ice were derived from the vertical ice temperature profiles.The freeze-up of lake ice and landfast sea ice occurred from late February to early March.The maximum lake-ice thicknesses occurred from late September to early October,with values of 156—177 cm.The maximum sea-ice thicknesses occurred later,from late October to late November,with values of 167—174 cm.The temporal variations in internal temperatures for both lake ice and landfast sea ice lagged those of local surface air temperatures.The high-frequency fluctuation of the local surface air temperature was evidently attenuated by ice cover.The temporal lag and the high-frequency attenuation were greater for sea ice than for lake ice,and more distinct for the lower ice layer than for the upper ice layer,which induced less conductive heat flux for sea ice than for lake ice,and less fluctuation in the conductive heat flux for the lower ice layer than for the upper ice layer.The enhanced desalination during the melt season consequently led to higher melt point temperature for sea ice,than for fresh-lake ice.
出处
《极地研究》
CAS
CSCD
北大核心
2011年第4期289-298,共10页
Chinese Journal of Polar Research
基金
国家重点基础研究发展计划(2010CB950301)
中国博士后基金(20100470400)
上海市博士后科研资助计划(11R21421800)资助
关键词
海冰
湖冰
热力学
厚度
温度
南极
sea ice
lake ice
thermodynamics
thickness
temperature
Antarctica
