2019-20 Honours project - Environmental Drivers of Antarctic Landfast Sea Ice Formation and Breakout

Antarctic Landfast sea ice (fast ice) is important climatologically, biologically and for logistics for short time-scale anomalies. Until recently, there hasn’t been an accurate, high-resolution fast ice extent dataset which can support an analysis on drivers of fast ice and most studies only investigate fast ice on limited regions of Antarctica in a limited time scale. There is a need to extend the spatial and temporal studying coverage to provide detailed information on the Antarctic coast over a longer period. This is the first detailed analysis to identify and quantify correlation between the environmental anomaly and fast ice anomaly mainly in the east Antarctic coast. By examining regional/local fast ice extent in in east Antarctic coast in the context of the broader and/or remote-teleconnected atmospheric circulation/properties using spatial correlation techniques, a strong correlation between NINO3 region and Lützow-Holm Bay fast ice and similar and significant correlation of regional scale factors from Lützow-Holm Bay to Mawson Coast mainly are found. The results of this thesis suggest that the pack ice, atmospheric factors and oceanic factors are important for interpreting fast ice anomalies. To identify and quantify correlation between the pack ice, temperature at 2m, wind at 10m, snow fall anomaly, sea surface temperature anomaly, ocean heat content anomaly and fast ice anomaly, backward multiple linear regression is conducted to demonstrate some predictive fast ice driver information by quantifying the correlation between different drivers and fast ice anomaly. The multiple linear regression also suggests that oceanic influences including pack ice are generally more important than atmospheric influences. Future experiments could be conducted to interpret fast ice anomalies in the context of the ocean mainly.

南极固定海冰（fast ice，固定冰）在气候学、生物学领域以及应对短期异常的后勤保障中均具有重要价值。直至近年，仍未出现可支撑固定冰驱动因子分析的高精度、高分辨率固定冰范围数据集，且多数研究仅针对南极有限区域与有限时段开展固定冰相关研究。因此，亟需拓展时空研究覆盖范围，以获取更长时间尺度下南极海岸的详细观测信息。本研究首次开展详细分析，旨在识别并量化主要分布于南极东海岸的环境异常与固定冰异常之间的相关性。研究采用空间相关分析技术，结合大尺度乃至远程遥相关的大气环流特征与属性，对南极东海岸的区域/局地固定冰范围展开考察，最终发现尼诺3区（NINO3 region）与吕佐夫-霍尔姆湾（Lützow-Holm Bay）固定冰之间存在显著相关关系，同时识别出吕佐夫-霍尔姆湾至莫森海岸（Mawson Coast）区域尺度因子的类似显著相关性。本论文的研究结果表明，浮冰群、大气因子与海洋因子均是解释固定冰异常的关键要素。为进一步识别并量化浮冰群、2米气温、10米风速、降雪异常、海表温度异常、海洋热含量异常与固定冰异常之间的关联，本研究开展了反向多元线性回归分析，通过量化不同驱动因子与固定冰异常的相关性，揭示了部分可用于预测固定冰的驱动因子信息。此外，多元线性回归分析结果还显示，包括浮冰群在内的海洋影响因子，整体上较大气影响因子更为重要。未来可开展相关实验，重点围绕海洋过程解析南极固定冰异常的形成机制。