EGU2020-1942
https://doi.org/10.5194/egusphere-egu2020-1942
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Occurrence of discontinuities in the ozone concentration data from three reanalyses

Peter Krizan
Peter Krizan
  • Institute of Atmospheric Physics, Prague, Czechia (krizan@ufa.cas.cz)

The aim of this presentation is to compare the occurrence of discontinuities in the ozone concentration data from the MERRA-2, ERA-5 and JRA-55 reanalyse, with the help of the Pettitt homogeneity test. We distinguish between the significant and insignificant discontinuities, according to the relation between the dispersion and the average ozone values before and after the discontinuity.    This occurrence is important for trend analyses, because the presence of discontinuities influences the values of trends and their significance. Discontinuities arise from the changing in the assimilation procedure, introducing new observation to the reanalyse, and changing of data quality. We search for their spatial, temporal and geographical occurrence. There are differences among these reanalyses. In the case of the MERRA-2 data, the transition from SBUV to EOS Aura data in 2004 has great impact on discontinuity behaviour. The frequent occurrence of discontinuities is seen in the uppermost model layers. The uppermost MERRA-2 layer is 0.1 hPa, while for ERA-5 this layer is 1 hPa. So there are differences in the vertical distribution of discontinuities among the reanalyses. The ozone data with the strong occurrence of the significant discontinuities is not suitable for trend analyses.   

How to cite: Krizan, P.: Occurrence of discontinuities in the ozone concentration data from three reanalyses, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-1942, https://doi.org/10.5194/egusphere-egu2020-1942, 2020

Displays

Display file