Observing the evolution of summer melt on multiyear sea ice with ICESat-2 and Sentinel-2
Observing the evolution of summer melt on multiyear sea ice with ICESat-2 and Sentinel-2
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DOI：
10.5194/tc-17-3695-2023
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发表时间：
2023-08
期刊：
影响因子：
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通讯作者：
Ellen M. Buckley;S. Farrell;U. Herzfeld;M. Webster;T. Trantow;O. Baney;K. Duncan;Huiling Han;Matthew Lawson
中科院分区：
文献类型：
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作者：
Ellen M. Buckley;S. Farrell;U. Herzfeld;M. Webster;T. Trantow;O. Baney;K. Duncan;Huiling Han;Matthew Lawson
抽象。我们调查了2020年融化季节的海冰状况，当时春季的暖空气温度异常导致融化开始早，融化季节延长，以及观察到的第二低的9月最小北极冰范围。我们专注于该地区最持久的冰盖和检查融化池深度检索从冰，云，和土地高程卫星-2（ICESat-2）使用两种不同的算法与时间序列的融化池分数和冰浓度来自哨兵-2图像，以获得有关融冰表面的见解在三个维度。我们发现，研究区域Sentinel-2得出的融化池比例在6月迅速增加，平均融化池比例在2020年6月24日达到峰值16% ± 6%，随后在7月3日缓慢下降至8% ± 6%，并在9月15日之前的剩余时间内保持在10%以下。海冰浓度在融化季节开始时一直很高（> 95%），直到7月4日，随着浮冰解体，它在7月30日降至70%的最低值，然后变得更加多变，在融化季节的剩余时间内从75%到90%不等。池塘深度从6月初的0.40 m ± 0.17 m的中值深度稳步增加，并在7月16日达到0.97 m ± 0.51 m的峰值，即使融化池部分已经开始减少。我们的研究结果表明，通过结合高分辨率的被动和主动遥感，我们现在有能力跟踪不断变化的融化条件，并观察整个夏季海冰覆盖的变化。
Abstract. We investigate sea ice conditions during the 2020 melt season, when warm air temperature anomalies in spring led to early melt onset, an extended melt season, and the second-lowest September minimum Arctic ice extent observed. We focus on the region of the most persistent ice cover and examine melt pond depth retrieved from Ice, Cloud, and land Elevation Satellite-2 (ICESat-2) using two distinct algorithms in concert with a time series of melt pond fraction and ice concentration derived from Sentinel-2 imagery to obtain insights about the melting ice surface in three dimensions. We find the melt pond fraction derived from Sentinel-2 in the study region increased rapidly in June, with the mean melt pond fraction peaking at 16 % ± 6 % on 24 June 2020, followed by a slow decrease to 8 % ± 6 % by 3 July, and remained below 10 % for the remainder of the season through 15 September. Sea ice concentration was consistently high (>95 %) at the beginning of the melt season until 4 July, and as floes disintegrated, it decreased to a minimum of 70 % on 30 July and then became more variable, ranging from 75 % to 90 % for the remainder of the melt season. Pond depth increased steadily from a median depth of 0.40 m ± 0.17 m in early June and peaked at 0.97 m ± 0.51 m on 16 July, even as melt pond fraction had already started to decrease. Our results demonstrate that by combining high-resolution passive and active remote sensing we now have the ability to track evolving melt conditions and observe changes in the sea ice cover throughout the summer season.