Monitoring the tabular icebergs C28A and C28B calved from the Mertz Ice Tongue using radar remote sensing data
Monitoring the tabular icebergs C28A and C28B calved from the Mertz Ice Tongue using radar remote sensing data
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使用雷达遥感数据监测默茨冰舌崩解的板状冰山 C28A 和 C28B
DOI：
10.1016/j.rse.2018.07.028
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发表时间：
2018-10-01
影响因子：
13.5
通讯作者：
Hui, Fengming
中科院分区：
文献类型：
--
作者：
Li, Tian;Shokr, Mohammed;Hui, Fengming
利用连续多波段雷达遥感资料，分析了源于C28冰山的两座板状冰山C28 A和C28 B的演变过程。监测工作始于2010年2月默茨冰舌C28号冰山崩解期间，于2012年4月结束。冰山面积的演变是由ENVISAT ASAR图像确定的，干舷变化是由CryoSat-2剖面得出的。在冰山漂移过程中，观察到两种冰山面积减少的模式。在南极夏季（10月至次年3月），冰山面积逐渐减小，这反映了冰山边缘的损耗、冰山侧壁的融化和波浪的侵蚀，C28 A冰山面积的减小速率在8.1 ~ 16.5km2/月之间。在南极冬季（4 - 9月），冰山面积有几次不连续的减少（突然下降），而大部分时间保持不变，这被解释为主要由海洋膨胀和基底融化引起的大裂谷裂解。据观察，这两座研究冰山的崩解面积在冬季较大。在同一冰山的不同位置，干舷以不同的速率下降（C28 A和C28 B在-0.02 +/- 0.22和-0.82 +/- 0.28 m/月之间），表明冰山的横向不均匀融化。C28 B在22个月搁浅期间的平均干舷变化率为-0.03 +/- 0.01米/月，远小于其在海洋中自由漂流时观察到的-0.76 +/- 0.23米/月。冰山周围的冷水状态可以帮助冰山保持稳定状态。这项研究揭示了雷达遥感在监测南极冰山时的潜在用途。
We analyzed the evolution processes of two tabular icebergs, C28A and C28B, originating from iceberg C28, using continuous multisource radar remote sensing data. The monitoring began during the calving of iceberg C28 from the Mertz Ice Tongue in February 2010 and ended in April 2012. The evolution of the iceberg area was determined from ENVISAT ASAR images, and the freeboard change was derived from CryoSat-2 profiles. Two patterns of iceberg area decreases are observed during iceberg drifting. In austral summer (from October to next March), iceberg area shows a gradual decrease and it is interpreted to represent edge wasting, sidewall melting and wave erosion, the gradual decrease of the area of C28A occurred at rates between 8.1 km(2)/month and 16.5 km(2)/month. In austral winter (from April to September), iceberg area has several discrete decreases (sudden drop) while it remained constant for most of the time, and it is interpreted to be large rift calving primarily caused by ocean swell and basal melting. Calving area of the two studied icebergs is observed to be greater in the winter. The freeboard decreased at different rates at different locations on the same iceberg (between -0.02 +/- 0.22 and -0.82 +/- 0.28 m/month for C28A and C28B), suggesting a laterally inhomogeneous melting of icebergs. The average rate of change of the C28B freeboard during its 22-month grounding period was -0.03 +/- 0.01 m/month, which is considerably smaller than the -0.76 +/- 0.23 m/month observed when it was freely drifting in the ocean. The cold-water regime surrounding the iceberg can help the iceberg maintain a stable state. This study reveals the potential use of radar remote sensing when monitoring Antarctic icebergs.