Considerations when using pre‐1979 NCEP/NCAR reanalyses in the southern hemisphere
Considerations when using pre‐1979 NCEP/NCAR reanalyses in the southern hemisphere
复制标题
在南半球使用 1979 年之前的 NCEP/NCAR 重新分析时的注意事项
DOI：
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发表时间：
2004
期刊：
影响因子：
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通讯作者：
W. Tennant
中科院分区：
文献类型：
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作者：
W. Tennant
NCEP/NCAR再分析资料在大气科学中有着广泛的应用。虽然这些数据是使用同质技术产生的，但大气观测系统的变化的影响是不可避免的。一个突出的影响是1978年引入了卫星数据，特别是在常规观测稀少的南半球。本文试图利用自组织映射(SOM)分析技术，量化卫星数据的引入对每日和年际变化尺度的影响程度。很明显，日环流统计在1979年前后有很大的不同，通常更典型的是1979年前的模式气候学。南半球中纬度地区的年际变化在1979年前似乎也有所减少。在对1979年前的南半球进行研究时，需要牢记这些注意事项。
NCEP/NCAR reanalysis data is used widely in the atmospheric sciences. Although these data are generated using homogenous techniques, the effect of changes in the atmospheric observing system is unavoidable. One prominent impact is the introduction of satellite data in 1978, particularly over the southern hemisphere where conventional observations are sparse. This paper attempts to quantify the extent to which the introduction of satellite data impacts both daily and inter‐annual scales of variability, using a Self‐Organizing Map (SOM) analysis technique. It is clear that daily circulation statistics are quite different before and after 1979, and are generally more typical of model climatology before 1979. Inter‐annual variability also appears to be reduced before 1979 in the mid‐latitudes of the southern hemisphere. These caveats need to be borne in mind when performing studies over the southern hemisphere pre‐1979.