Retrieval of ice cloud microphysical parameters using the CloudSat millimeter‐wave radar and temperature
Retrieval of ice cloud microphysical parameters using the CloudSat millimeter‐wave radar and temperature
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DOI：
10.1029/2008jd010049
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发表时间：
2009-04
影响因子：
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通讯作者：
R. Austin;A. Heymsfield;G. Stephens
中科院分区：
文献类型：
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作者：
R. Austin;A. Heymsfield;G. Stephens
[1]一种新的冰云微物理遥感检索已开发用于毫米波雷达从地面，空中，或空间传感器。从早期的检索，使用测量的雷达反射率因子连同先验信息的可能的云目标，新的检索包括温度信息，以及帮助确定正确的区域的状态空间，特别是对于那些尺寸分布参数，较少受雷达测量。这些算法已被用作CloudSat 2B-CWC-RO标准数据产品第3版和第4版中的冰云检索算法。对以前和当前的检索算法进行了几项比较研究：一些涉及在模拟雷达数据上的算法测试（基于实际的云探测器数据或云解析模型）和其他以R 04 2B-CWC-RO产品的统计比较为特色的产品（目前的算法）冰云质量检索由其他航天器，机载，和地面仪器或使用相同CloudSat雷达数据的替代算法。涉及模拟雷达数据的云探测器数据库的基础上的比较表现出良好的性能，与冰水含量（IWC）的偏差误差估计小于40%。与其他仪器估计的冰水含量和冰水路径的比较是混合的。当比较仅限于使用相同CloudSat雷达测量的不同检索方法时，CloudSat R 04的结果通常与IWC < 1000 mg m−3的替代IWC检索在12公里以下的高度一致，但在较高的冰含量和高度上不同，要么超过其他检索值，要么落入检索值的范围内。所有这些方法的验证和协调将继续是进一步研究的主题。
[1] A new remote sensing retrieval of ice cloud microphysics has been developed for use with millimeter-wave radar from ground-, air-, or space-based sensors. Developed from an earlier retrieval that used measurements of radar reflectivity factor together with a priori information about the likely cloud targets, the new retrieval includes temperature information as well to assist in determining the correct region of state space, particularly for those size distribution parameters that are less constrained by the radar measurements. These algorithms have served as the ice cloud retrieval algorithms in Releases 3 and 4 of the CloudSat 2B-CWC-RO Standard Data Product. Several comparison studies have been performed on the previous and current retrieval algorithms: some involving tests of the algorithms on simulated radar data (based on actual cloud probe data or cloud resolving models) and others featuring statistical comparisons of the R04 2B-CWC-RO product (current algorithm) to ice cloud mass retrievals by other spaceborne, airborne, and ground-based instruments or alternative algorithms using the same CloudSat radar data. Comparisons involving simulated radar data based on a database of cloud probe data showed generally good performance, with ice water content (IWC) bias errors estimated to be less than 40%. Comparisons to ice water content and ice water path estimates by other instruments are mixed. When the comparison is restricted to different retrieval approaches using the same CloudSat radar measurements, CloudSat R04 results generally agree with alternative IWC retrievals for IWC < 1000 mg m−3 at altitudes below 12 km but differ at higher ice contents and altitudes, either exceeding other retrievals or falling within a spread of retrieval values. Validation and reconciliation of all these approaches will continue to be a topic for further research.