Assessing uncertainties in sea ice extent climate indicators
Assessing uncertainties in sea ice extent climate indicators
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DOI：
10.1088/1748-9326/aaf52c
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发表时间：
2019-03
影响因子：
6.7
通讯作者：
W. Meier;J. Stewart
中科院分区：
文献类型：
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作者：
W. Meier;J. Stewart
从两个方面评估了被动微波传感器反演海冰范围（海冰覆盖总面积，浓度>15%）的不确定度。绝对不确定度（准确度）是根据几种产品之间的程度比较来评价的。不同产品的范围之间存在明显的偏差，根据季节和半球的不同，范围为500 000至1 × 106 km 2。这些偏差是由于算法对冰缘条件的敏感性和不同传感器的空间分辨率的差异。相对不确定性是通过检查国家冰雪数据中心海冰指数产品的范围来评估的。最大的不确定性来源是近实时产品和最终产品之间的不确定性，约100 000平方公里，这是由于输入源数据不同以及处理和质量控制不同造成的。为了实现一致的处理，使用不同的输入源数据并通过改变浓度算法参数来评估不确定性。这就产生了30 000-70 000平方公里的相对不确定性。北极的最小范围不确定性为40 000平方公里。由于传感器转换，与记录的前几部分相比，不确定性可能更高。这项研究首次提供了海冰范围不确定性的定量估计。
The uncertainties in sea ice extent (total area covered by sea ice with concentration >15%) derived from passive microwave sensors are assessed in two ways. Absolute uncertainty (accuracy) is evaluated based on the comparison of the extent between several products. There are clear biases between the extent from the different products that are of the order of 500 000 to 1 × 106 km2 depending on the season and hemisphere. These biases are due to differences in the algorithm sensitivity to ice edge conditions and the spatial resolution of different sensors. Relative uncertainty is assessed by examining extents from the National Snow and Ice Data Center Sea Ice Index product. The largest source of uncertainty, ∼100 000 km2, is between near-real-time and final products due to different input source data and different processing and quality control. For consistent processing, the uncertainty is assessed using different input source data and by varying concentration algorithm parameters. This yields a relative uncertainty of 30 000–70 000 km2. The Arctic minimum extent uncertainty is ∼40 000 km2. Uncertainties in comparing with earlier parts of the record may be higher due to sensor transitions. For the first time, this study provides a quantitative estimate of sea ice extent uncertainty.