论文部分内容阅读
采用第19次中国南极科考采集的冰芯样品、数据,基于海冰的“冻结日”记录,使用海冰一维热力学模型来计算纳拉海峡固定冰的生长厚度.考虑气象条件以及冰情观测结果,将该模型的计算海冰厚度和实测厚度进行比较发现,在纳拉海峡存在着多年生长的海冰.对采集于南极洲中山站附近纳拉海峡的固定冰冰芯样品进行结构、盐度和稳定氧同位素(δ18O)分析,获取了海冰的结构和盐度剖面特征、冰芯雪冰、附加冰的含量、雪冰中的雪以及全部冰芯中雪所占的百分比.结果表明:样品冰芯具有典型的海冰特征结构,如柱状冰水平方向的C轴以及上部粒状冰层和下部柱状冰层结构特征,部分柱状冰中间存在着粒状冰夹层;盐度和δ18O剖面也显示了多年冰生长的证据.海冰的结构和氧同位素特征表明,纳拉海峡固定冰的生长主要受热力学过程控制,其结果和2000年1月至2003年2月人工冰情观测结果一致,观测中没有发现冰脊、叠置等动力过程.附加冰在冰芯中所占的比例平均为5.01%.使用不同的同位素标准来区分雪冰层,估计研究区域平均有多达16.4%～37.9%的雪冰,海冰粒状层中雪的部分约占全部冰厚度的0.8%～23.5%.
Using the ice core sample collected from the 19th China Antarctic Research Area, data, and the “Freeze Day” record based on sea ice, a one-dimensional thermodynamic model of sea ice was used to calculate the thickness of the ice in the Nala Channel. Considering the meteorological conditions and The results of ice conditions show that the sea ice thickness over the years in the Nala strait is more than that of the ice thickness measured in this model.For the samples of ice cores fixed in the Nala strait near Antarctica, Salinity and stable oxygen isotope (δ18O) analysis, the structure and salinity profiles of sea ice, the ice core snow ice, the amount of additional ice, the snow in snow ice and the percentage of snow in all ice cores were obtained. The results show that the ice core of the sample has the typical sea ice features such as C-axis in the horizontal direction of columnar ice and structural features of the upper and lower columnar ice layers. Particulate ice deposits exist in some of the columnar ice; salinity and δ18O profiles Showing the evidence of multi-year ice growth.The sea ice structure and oxygen isotopic characteristics show that the growth of the fixed ice in the Nora Channel is mainly controlled by the thermodynamic process and the results are consistent with those from January 2000 to February 2003 The results of ice conditions were consistent, and no ice ridges, overlying processes and other dynamic processes were observed during the observation. The average percentage of additional ice in ice cores was 5.01% .Using different isotopic criteria to distinguish snow ice layer, it is estimated that the average of the study area As much as 16.4% ~ 37.9% snow ice, part of the snow in the granular layer of sea ice accounts for about 0.8% ~ 23.5% of the total ice thickness.