4种再分析资料确定的大气边界层高度的差异性

An intercomparison study on the planetary boundary layer height of four reanalysis datasets

利用1980年1月-2010年12月全球无线电探空数据集(IGRA)计算的大气边界层高度(PBL),对CFSR、CERA-20C、ERA-interim和MERRA2再分析资料确定的PBL进行评估.结果表明, 4种再分析资料分析的PBL的空间分布特征与IGRA的分析结果具有较好的一致性,但再分析资料确定的PBL数值低于IGRA的计算结果;4种再分析资料与IGRA计算的PBL误差值较小的区域都位于00:00和12:00的对流边界层发展稳定期,且误差主要集中于-40%~-60%.其中MERRA2资料的计算结果误差整体较小,与IGRA的结果最接近, CFSR和ERA-interim的计算结果次之, CERA-20C的计算结果误差最大. 4种再分析资料确定的PBL与IGRA的结果在0°~60°E的欧亚大陆上表现出较强的正相关性,而00:00的CFSR和12:00的ERA-interim的结果与IGRA的计算结果相关性优于其他再分析资料的计算结果 .大气边界层发展充分时再分析资料对PBL的判定不确定性较小,与IGRA计算的PBL误差小,相关性强;大气边界层发展期或衰退期,结果反之.研究PBL的空间分布特征时, MERRA2资料与IGRA的计算结果具有较好的一致性;研究PBL长期变化特征时, CFSR和ERA-interim的计算结果一致性好.

The planetary boundary layer height(PBL) of four reanalysis datasets(CFSR, CERA-20 C,ERA-interim, and MERRA2) was compared with the integrated global radiosonde archive(IGRA) from January 1980 to December 2010. The results showed that the spatial distribution characteristics of the four reanalysis datasets had a good consistency with IGRA, but the PBL of reanalysis datasets was lower than the radiosonde data. When the PBL of the convective boundary layer was developed completely at00:00 and 12:00, the spatial distribution of relative mean deviation(RMD) of the four reanalysis datasets was lower, and RMD mainly was concentrated between-40% and-60%. Of the four reanalysis datasets, MERRA2 was closest to IGRA, followed by CFSR and ERA-interim, with the RMD of CERA-20 C being largest. The four reanalysis datasets and IGRA showed a strong positive correlation on Eurasia from 0°~60°E, especially the CFSR data at 00:00 and the ERA-interim at 12:00. When the boundary layer was fully developed, the RMD of the reanalysis decreased and the correlation increased, while in other periods, the result was reversed. For studying the spatial distribution characteristics of the PBL,MERRA2 had good consistency with IGRA. When studying the long-term variation characteristics of the boundary layer, CFSR and ERA-interim had a good consistency.