5:15 PM - 7:15 PM
[AAS06-P02] Representation of ozone quasi-biennial oscillation (QBO) in JRA-3Q
Keywords:ozone QBO, reanalysis, JRA-3Q
This study evaluates the representation of the quasi-biennial oscillation in ozone (ozone QBO) in the Japanese Reanalysis for Three Quarters of a Century (JRA-3Q). Ozone is used as a boundary condition in the JRA-3Q reanalysis system and plays an important role in determining temperature and wind distribution. Reanalysis ozone used or produced by the Japanese Meteorological Agency or other organizations represent a realistic distribution of column and ozone mixing ratio in the stratosphere by assimilating ozone observations. The monthly mean zonal wind, temperature and ozone mixing ratio are analyzed from global reanalysis datasets of JRA-3Q, ERA5, MERRA-2, and JRA-55. The ozone measurements produced by the SPARC Data Initiative from 1978 to 2010 and Aura MLS satellite ozone dataset from 2005 to 2022 are used in the form of monthly zonal mean.
Here, we examine the coherence of the ozone QBO with dynamical QBO in the post- and pre-satellite eras from the state-of-the-art reanalyses. It should be noted that the ozone in JRA-3Q was produced using a stratosphere-troposphere ozone chemistry model driven by JRA-55 zonal wind, and that in JRA-55 was produced using a stratosphere ozone chemistry model driven by JRA-25 zonal wind. The observed ozone QBO (SPARC-DI + AURA-MLS) shows two major power regions: the lower part of ozone QBO primarily driven by dynamics and the upper part one mainly driven by chemistry. There is a minimum power of the ozone QBO that is clearly seen at 15–20 hPa. However, the separation of the upper and lower parts of the ozone QBO in the reanalysis is less clear. These results suggest that the observational data used for data assimilation are not homogeneous throughout the satellite observed period and that the data assimilation system used in the reanalysis is inconsistently between dynamics and chemistry.
Here, we examine the coherence of the ozone QBO with dynamical QBO in the post- and pre-satellite eras from the state-of-the-art reanalyses. It should be noted that the ozone in JRA-3Q was produced using a stratosphere-troposphere ozone chemistry model driven by JRA-55 zonal wind, and that in JRA-55 was produced using a stratosphere ozone chemistry model driven by JRA-25 zonal wind. The observed ozone QBO (SPARC-DI + AURA-MLS) shows two major power regions: the lower part of ozone QBO primarily driven by dynamics and the upper part one mainly driven by chemistry. There is a minimum power of the ozone QBO that is clearly seen at 15–20 hPa. However, the separation of the upper and lower parts of the ozone QBO in the reanalysis is less clear. These results suggest that the observational data used for data assimilation are not homogeneous throughout the satellite observed period and that the data assimilation system used in the reanalysis is inconsistently between dynamics and chemistry.