Quality assessment of a satellite altimetry data product in the Nordic, Barents, and Kara seas
Quality assessment of a satellite altimetry data product in the Nordic, Barents, and Kara seas
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DOI：
10.1029/2011jc007557
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发表时间：
2012-03
影响因子：
--
通讯作者：
D. Volkov;M. Pujol
中科院分区：
文献类型：
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作者：
D. Volkov;M. Pujol
[1]卫星测高提供了高质量的海面高度数据，已成功地用于研究海平面和地表地转环流在不同空间和时间尺度上的变异性。然而，由于持续的海冰覆盖，高纬度地区传统上一直被避开。大多数验证研究都集中在极圈以下的区域。在这篇文章中，我们检查了北欧、巴伦支海和喀拉海网格化卫星测高产品的质量和性能。利用现有的验潮仪记录对沿海地区的高程海平面进行了验证。结果表明，在北欧海的大部分地区，测高和验潮仪测量的均方根差以及季节周期的幅度和相位是一致的。该协议在巴伦支海和喀拉海的浅水区恶化，受季节性海冰的影响，测高数据受到未分辨高频信号残留混叠的污染。对验潮仪位置的线性趋势的比较表明，在解释该区域海平面的长期变化时需要考虑的差异。在远离海岸的地方，测高数据将与漂流轨迹进行比较，并根据埃克曼洋流进行校正。发现漂移轨迹与高度计海平面的中尺度变化一致。这项研究首次在高纬度海域对格网卫星测高数据产品进行了全面验证。
[1] Satellite altimetry provides high-quality sea surface height data that have been successfully used to study the variability of sea level and surface geostrophic circulation at different spatial and temporal scales. However, the high-latitude regions have traditionally been avoided due to the persistent sea ice cover. Most of the validation studies have focused on the areas below the polar circles. In this paper we examine the quality and performance of a gridded satellite altimetry product in the Nordic, Barents, and Kara seas. The altimetric sea level in coastal areas is validated using available tide gauge records. We show that at most locations in the Nordic seas the altimetry and tide gauge measurements are in a good agreement in terms of the root-mean square differences and the amplitudes and phases of the seasonal cycle. The agreement deteriorates in the shallow areas of the Barents and Kara seas subject to the seasonal presence of sea ice, and where the altimetry data are contaminated by the residual aliasing of unresolved high-frequency signals. The comparison of linear trends at the locations of tide gauges reveals discrepancies that need to be taken into account when interpreting long-term changes of sea level in the region. Away from the coast the altimetry data are compared to drifter trajectories, corrected for Ekman currents. The drifter trajectories are found consistent with the mesoscale variability of the altimetric sea level. This study provides the first comprehensive validation of a gridded satellite altimetry data product in the high-latitude seas.