Sea ice melting is very common in Arctic summer, so it is important to study ice melting noise. This paper analyzes a 456 min time series of under-ice noise that was recorded at a depth of 29.9 m in the central Arctic Ocean when the area was approximately 89% ice cover, UTC time, on August 8th, 2017. When the air temperature was higher than the freezing point of the surface sea water, the under-ice noise levels increased. In particular, the noise levels at 80–240 Hz and 380–660 Hz had two broad peaks and increased by 5–15 dB, furthermore, there was a large number of transient signals in the noise data. When the air temperature decreased and was less than the freezing point of the surface sea water, the under-ice noise levels gradually decreased, the broad peaks of the under-ice noise levels gradually disappeared, and the transient signals also disappeared. At the above two frequency bands, the correlation coefficients between the air temperature and under-ice noise levels were generally above 0.5 and reached a maximum value of 0.81. These results suggest that the changes in the under-ice noise levels could be attributed to sea ice melting.

海冰融化在北极夏季非常普遍，因此研究冰融化噪声非常重要。本文分析了456分钟的冰下噪声时间序列，该时间序列记录于北冰洋中部29.9 m深度，当时该区域的冰盖面积约为89％，UTC时间，2017年8月8日。高于地表海水的冰点，冰下噪音水平增加。特别是，在80–240 Hz和380–660 Hz的噪声水平有两个宽的峰值，并增加了5–15 dB，此外，噪声数据中存在大量的瞬态信号。当气温降低并低于地表海水的冰点时，冰下噪音水平逐渐降低，冰下噪音水平的宽峰逐渐消失，瞬态信号也消失了。在上述两个频段，空气温度与冰下噪声水平之间的相关系数通常高于0.5，并达到最大值0.81。这些结果表明，冰底噪声水平的变化可能归因于海冰融化。