2016年南极中山站固定冰冰厚观测分析

Observation and analysis of landfast ice arounding Zhongshan Station,Antarctic in 2016

极区海冰是全球气候系统的重要组成部分,南极的固定冰普遍存在于其沿海地区,中山站周边固定冰一般在11月中下旬达到最厚。海冰厚度是海冰的重要参数之一,2016年在南极中山站附近3个站点(S1、S2、S3站点)共布放了4套温度链浮标,包括1套SIMBA (Snow and Ice Mass Balance Array)温度链浮标和3套太原理工大学温度链浮标(TY温度链浮标),SIMBA温度链浮标每天观测4次,TY温度链浮标每小时观测1次。利用浮标观测的温度剖面以及海冰和海水间不同介质温度差异计算得到海冰厚度。在S3站点,同时布放了SIMBA温度链浮标和TY温度链浮标。温度链浮标计算冰厚和人工钻孔观测冰厚比较结果显示,S1站点TY温度链浮标计算的海冰厚度平均误差和均方根误差分别为3.3 cm和14.7 cm,S2站点和S3站点分别为6.6 cm、6.9 cm以及4.0 cm、4.8 cm。S3站点的SIMBA温度链浮标计算冰厚和人工观测冰厚的平均误差和均方根误差为8.2 cm和9.7 cm。因而S3站点TY温度链浮标计算的海冰厚度更接近人工观测的结果。进一步对Stefan定律海冰生长模型进行对比,模型计算得到的海冰生长率为0.1~0.8 cm/d,生长率快于TY温度链浮标的结果,且受积雪影响明显。相比于卫星遥感反演冰厚的误差和观测时段的限制以及有限的人工观测,2种温度链浮标未来对于中山站附近海冰的长期监测均有重要的应用价值。

Sea ice is an important part of the global climate system.Landfast ice is commonly found in the Antarctic coastal area,which reached the thickest in the middle and late November around Zhongshan Station.Sea ice thickness is one of the important parameters of the sea ice.We presented measurements by taken 1 SIMBA(Snow and Ice Mass Balance Array)buoy and 3 TY buoys to monitor ice thickness based on the bias of different linear temperature gradient in air,snow,ice and sea water in three different landfast ice stations(S1,S2 and S3)in the Prydz Bay outside Zhongshan Station in 2016.The SIMBA measures vertical temperature profiles 4 times a day and TY measures vertical temperature per hour.Both SIMBA and TY buoys were set up in S3 station.Compared with borehole in situ measurements,the ice thickness derived by TY buoys had a mean bias and RMSE of 3.3 cm and14.7 cm in S1 Station,6.6 cm and 6.9 cm in S2 Station and 4.0 cm and 4.8 cm in S3 Station.And the mean bias and RMSE for the SIMBA buoys in S3 Station compared with borehole in situ measurements were 8.2 cm and 9.7 cm.The sea ice thickness derived by TY buoys were more agreement with the borehole in situ measurements compared with the sea ice thickness derives from SIMBA buoys in S3 Station.The result of Stefan’s law of ice growth model shows the sea ice growth process and the ice growth rate varied between 0.1 cm/d to 0.8 cm/d,which is faster than the result of TY buoys and is affected by the snow thickness.While compare with limited borehole in situ sea ice thickness measurements and the great uncertain in the sea ice thickness derived by remote sense data,the error for both the TY and SIMBA buoys are reasonable,which will benefit to the future sea ice thickness monitor near Zhongshan Station.