Articles | Volume 17, issue 23
Research article
11 Dec 2017
Research article |  | 11 Dec 2017

Estimating uncertainties in the SBUV Version 8.6 merged profile ozone data set

Stacey M. Frith, Richard S. Stolarski, Natalya A. Kramarova, and Richard D. McPeters

Abstract. The combined record of total and profile ozone measurements from the solar backscatter ultraviolet (SBUV) and SBUV/2 series of instruments, known as the SBUV Merged Ozone Data (MOD) product, constitutes the longest satellite-based ozone time series from a single instrument type and as such plays a key role in ozone trend analyses.

Following the approach documented in Frith et al. (2014) to analyze the merging uncertainties in the MOD total ozone record, we use Monte Carlo simulations to estimate the potential for uncertainties in the calibration and drift of individual instruments in the profile ozone merged data set. We focus our discussion on the trends and associated merging uncertainty since 2001 in an effort to verify the start of ozone recovery as predicted by chemistry climate models. We find that merging uncertainty dominates the overall estimated uncertainty when considering only the 15 years of data since 2001. We derive trends versus pressure level for the MOD data set that are positive in the upper stratosphere as expected for ozone recovery. These trends appear to be significant when only statistical uncertainties are included but become not significant at the 2σ level when instrument uncertainties are accounted for. However, when we use the entire data set from 1979 through 2015 and fit to the EESC (equivalent effective stratospheric chlorine) we find statistically significant fits throughout the upper stratosphere at all latitudes. This implies that the ozone profile data remain consistent with our expectation that chlorine is the dominant ozone forcing term.

Short summary
We have combined measurements from a series of SBUV instruments to create the longest continuous satellite-based profile ozone record from a single instrument type (1979–2016). We assess the consistency of the profile ozone measurements across instruments to assign an uncertainty to the merged record. Time-series analysis shows that upper-stratospheric ozone since 2001 is increasing, but the results are not yet statistically significant when the merged record uncertainties are included.
Final-revised paper