Abstract:

The thickness of sea ice is a key parameter in the study of global climate change. The measurement of Sea ice thickness remains a tough issue in current research of sea ice. Electromagnetic (EM) measurement of sea ice is an efficient, fast and high-precision method. In the present paper, we used shipborne data in China's fourth Arctic scientific expedition, which was acquired by EM31-ICE electromagnetic induction device, laser range finder as well as sonar . Through pre-processing the preliminary data of sea ice thickness, and then combined with calibration information from ice core samples in the long-term ice stations, we obtained the correction parameters of EM31-ICE. Results through the analysis of anomalous data together with wavelet denoising and statistical processing, demonstrate that: ice thickness mainly varies between 0.5m and 2.5m in the way to arctic, whereas in the back way from arctic, it becomes thinner, ranging from 0.5m to 2.0m. The thickness of sea ice in high-latitude regions is significantly greater than those in low-latitude regions. Moreover, in high-latitude regions, two peaks appear in the histograms of sea ice thickness, while in the low-latitude regions only one peak appears. Throughout the whole go and return process, ice with the thickness over 4m is less than 1%.

Key words: Arctic, sea ice thickness, shipborne measurement, EM31-ICE, wavelet denoising