A multi-instrument comparison of integrated water vapour measurements at a high latitude site
A multi-instrument comparison of integrated water vapour measurements at a high latitude site
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DOI：
10.5194/acp-12-10925-2012
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发表时间：
2012-11
影响因子：
6.3
通讯作者：
S. Buehler;S. Östman;C. Melsheimer;G. Holl;S. Eliasson;V. John;T. Blumenstock;F. Hase;G. Elgered;U. Raffalski;T. Nasuno;M. Satoh;M. Milz;J. Mendrok
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文献类型：
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作者：
S. Buehler;S. Östman;C. Melsheimer;G. Holl;S. Eliasson;V. John;T. Blumenstock;F. Hase;G. Elgered;U. Raffalski;T. Nasuno;M. Satoh;M. Milz;J. Mendrok
我们比较测量的综合水汽（IWV）在亚北极地区（基律纳，北方瑞典）从五个不同的传感器和检索方法：无线电探空仪，全球定位系统（GPS），地基傅里叶变换红外（FTIR）光谱仪，地基微波辐射计，和卫星微波辐射计（AMSU-B）。此外，我们还比较了ERA中期模型再分析数据。基于GPS的IWV数据具有最高的时间覆盖率和分辨率，并被选为参考数据集。所有的数据集都相当一致，但地面微波仪器只有在数据经过云过滤的情况下才会如此。我们还解决了两个问题，是一般的相互比较研究，不同的低海拔限制的IWV集成的影响，和代表性误差的影响。我们开发的方法来纠正前者，估计后者的随机误差的贡献。一项文献调查显示，不同技术之间的系统性差异是研究依赖性的，没有显示出整体一致的模式。因此，进一步提高IWV测量的绝对准确性和提供气候质量时间序列仍然是具有挑战性的问题。
We compare measurements of integrated water vapour (IWV) over a subarctic site (Kiruna, Northern Sweden) from five different sensors and retrieval methods: Radiosondes, Global Positioning System (GPS), ground-based Fourier-transform infrared (FTIR) spectrometer, groundbased microwave radiometer, and satellite-based microwave radiometer (AMSU-B). Additionally, we compare also to ERA-Interim model reanalysis data. GPS-based IWV data have the highest temporal coverage and resolution and are chosen as reference data set. All datasets agree reasonably well, but the ground-based microwave instrument only if the data are cloud-filtered. We also address two issues that are general for such intercomparison studies, the impact of different lower altitude limits for the IWV integration, and the impact of representativeness error. We develop methods for correcting for the former, and estimating the random error contribution of the latter. A literature survey reveals that reported systematic differences between different techniques are study-dependent and show no overall consistent pattern. Further improving the absolute accuracy of IWV measurements and providing climate-quality time series therefore remain challenging problems.