Occurrence of discontinuities in the ozone concentration data from three reanalyses

Abstract. Ozone is a very important trace gas in the stratosphere and thus we need to know its time evolution over the globe. The ground based measurements are rare, especially in the Southern Hemisphere. Satellite ozone data have broader coverage, but they are not available from everywhere. On the other hand, the reanalyse data have regular spatial and temporal structure, which is very good for trend analyses. But there are discontinuities in these data.These discontinuities may influence the result of trend studies. The aim of this paper is to detect the discontinuity occurrence (DO) in the following reanalyses: MERRA-2, ERA-5 and JRA-55 with the help of the Pettitt homogeneity test at all common layers above 500 hPa. The discontinuities are sorted according to their size to the significant and the insignificant ones; the former can affect the ozone trend studies. It was shown that DO for the significant discontinuities is the smallest in JRA-55. In the upper model layers, the discontinuity occurrence is the highest. The other area of high DO is the troposphere.