Discontinuities in the Ozone Concentration Time Series from MERRA 2 Reanalysis

0518052 - ÚFA 2020 RIV CH eng J - Journal Article
Križan, Peter - Kozubek, Michal - Laštovička, Jan
Discontinuities in the Ozone Concentration Time Series from MERRA 2 Reanalysis.
Atmosphere. Roč. 10, č. 12 (2019), č. článku 812. E-ISSN 2073-4433
R&D Projects: GA ČR(CZ) GA18-01625S
Institutional support: RVO:68378289
Keywords : merra ozone data * discontinuities in reanalysis time series * trend analyses
OECD category: Meteorology and atmospheric sciences
Impact factor: 2.397, year: 2019
Method of publishing: Open access
https://www.mdpi.com/2073-4433/10/12/812

Artificial discontinuities in time series are a great problem for trend analysis because they influence the values of the trend and its significance. The aim of this paper is to investigate their occurrence in the Modern-Era Retrospective analysis for Research and Applications, version 2 (MERRA 2) ozone concentration data. It is the first step toward the utilization of the MERRA 2 ozone data for trend analysis. We use the Pettitt homogeneity test to search for discontinuities in the ozone time series. We showed the data above 4 hPa are not suitable for trend analyses due to the unrealistic patterns in an average ozone concentration and due to the frequent occurrence of significant discontinuities. Below this layer in the stratosphere, their number is much smaller, and mostly, they are insignificant, and the patterns of the average ozone concentration are explainable. In the troposphere, the number of discontinuities increases, but they are insignificant. The transition from Solar Backscatter Ultraviolet Radiometer (SBUV) to Earth Observing System (EOS) Aura data in 2004 is visible only above 1 hPa, where the data are not suitable for trend analyses due to other reasons. We can conclude the MERRA 2 ozone concentration data can be used in trend analysis with caution only below 4 hPa.
Permanent Link: http://hdl.handle.net/11104/0303246