Monitoring the melt season length of the Barnes Ice Cap over the 1979–2010 period using active and passive microwave remote sensing data
Monitoring the melt season length of the Barnes Ice Cap over the 1979–2010 period using active and passive microwave remote sensing data
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DOI：
10.1002/hyp.9382
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发表时间：
2012-08
影响因子：
3.2
通讯作者：
Florent Dupont;A. Royer;A. Langlois;A. Gressent;G. Picard;M. Fily;P. Cliche;M. Chum
中科院分区：
文献类型：
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作者：
Florent Dupont;A. Royer;A. Langlois;A. Gressent;G. Picard;M. Fily;P. Cliche;M. Chum
巴恩斯冰帽（BIC）位于巴芬岛（努纳武特，加拿大）是加拿大北极群岛最南部的冰帽之一。观测数据提供了证据，表明由于最近北极气候变暖，融化、变薄和轮廓衰退加剧。1979-2010年期间，BIC夏季融化季节的持续时间是使用19 GHz水平偏振亮温数据的阈值算法得出的;被动微波卫星测量包括来自准每日扫描多通道微波辐射计和特殊传感器微波成像仪的数据。我们的研究结果表明，融化季节从1979-1987年开始的65.6 ± 6天延长到2002-2010年结束时的87.1 ± 7.8天，延长了33%。融化天数的年际变化与来自QuikSCAT散射仪的重叠2000-2009年期间的主动微波后向散射数据一致。此外，ICESat高度计的海拔变化数据证实了BIC在2003-2009年期间以-0.75米/年的平均速度变薄。对于我们分析的32年期间，对北美区域再分析和克莱德河自动气象站数据与夏季和年度气温以及正日数年总和的相关性进行了检查。在过去的十年中，还审查了与中分辨率成像分光仪的地表温度数据的相关性。这些调查的结果表明，这些气候指标并不能充分解释观测到的BIC融化变化。在2011年3月为期10天的实地考察期间，在BIC峰会附近收集的地面冰雪测量结果提供了对表面特性的深入了解，并证实了用于融化检测的遥感不变阈值算法的相关性。版权所有© 2012约翰威利父子有限公司.
The Barnes Ice Cap (BIC) located on Baffin Island (Nunavut, Canada) is one of the most southern ice caps of the Canadian Arctic Archipelago. Observational data provide evidence of increased melting, thinning and contour recession due to recent climate warming in the Arctic. The duration of the summer melt season for the BIC, over the period 1979–2010, was derived using a threshold algorithm for 19 GHz horizontal polarization brightness temperature data; the passive microwave satellite measurements included data from the quasi‐daily Scanning Multichannel Microwave Radiometer and the Special Sensor Microwave Imager. Our results show the melt season lengthened by 33% from 65.6 ± 6 days at the beginning of the period (1979–1987) to 87.1 ± 7.8 days towards the end (2002–2010). The interannual variations of the number of melt days were in agreement with those derived from active microwave backscatter data from the QuikSCAT scatterometer for the overlapping 2000–2009 period. In addition, elevation change data from the ICESat altimeter confirmed the thinning of the BIC at a mean rate of −0.75 m/year for the 2003–2009 period. For the 32‐year period that we analysed, correlations with summer and annual air temperature and annual sum of positive days were examined for both the North American Regional Reanalysis and the Clyde River Automatic Weather Station data. Correlations with land surface temperature data from MODIS were also examined over the last decade. The results of these investigations showed that these climate indicators did not adequately explain the observed melt variations for the BIC. Ground‐based snow and ice measurements collected near the BIC summit during a 10‐day field campaign in March 2011 provided insights onto the surface properties and confirm the relevance of the remote sensing invariant threshold algorithm used for melt detection. Copyright © 2012 John Wiley & Sons, Ltd.