In this contribution, we give an overview of the ozonesonde stations that homogenized their ECC time series according to the principles of the O3S-DQA activity. We also present the roadmap to increase the number of homogenized (European) ozonesonde stations, in close collaboration with the station PIs. We will also discuss the different possibilities to make the already homogenized datasets...
An international effort to improve ozonesonde data quality and to reevaluate historical records has made significant improvements in the accuracy of global network data. However, between 2014 and 2016, ozonesonde total column ozone (TCO; O3) at 14 of 37 regularly reporting stations exhibited a sudden drop-off relative to satellite measurements. The ozonesonde TCO drop is 3-7 % compared to...
After the Montreal protocol banned ozone depleting substances, first signs of an ozone recovery in the stratosphere were observed starting in 1997. Recent studies have reported positive trends indicating that ozone is recovering in the upper stratosphere at mid-latitudes. However, stratospheric ozone trends from various ground-based data sets still differ in magnitude.
To partly explain such...
Within the Network for the Detection of Atmospheric Composition Changes (NDACC), ozone total content and vertical distribution are monitored by various measurement techniques at Observatoire de Haute-Provence (44°N, 6°E) in Southern France. For the vertical distribution, these techniques include two ozone lidars for the measurement of stratospheric and tropospheric ozone vertical profiles, in...
The study aims to revise historical NOAA Umkehr records with improved stray light corrections. Overpass data are generated for the GB sites using the combination techniques of the NOAA Cohesive (COH) zonal ozone product. The optimized Umkehr and COH station overpass data are compared to evaluate the long-term consistency in these records and improve homogenization techniques. The final goal is...
Update stability OMPS-LP (tangent height and spectral). Impact on different L2 data records (NASA, USask, UBremen) and merged L3.
This short presentation will give an update related to the continuing OSIRIS data record and how it fits into both the SAGE II/OSIRIS and the SAGE II/OSIRIS/OMPS-LP USask 2D time series. These time series will be evaluated through comparison with an MLS data record that has been converted from pressure and volume mixing ratio to altitude and number density using both ERA Interim and shifted...
The motivation for the initial phase of the SPARC Long-term Ozone Trends in the Stratosphere (LOTUS) project was to clarify from a community perspective our best estimate of stratospheric profile ozone trends and related uncertainties based on a variety of satellite and ground-based observations. The satellite-based records were all merged ozone products, many of which in part shared data from...
There are now more than 40 years of satellite and ground-based ozone observations, a vast amount of data with which to diagnose variability and trends in stratospheric ozone. Despite this, confidence in the status of long-term trends in ozone remains uncertain, with the way that data from disparate sources are merged being a leading reason uncertainties remain high.
We have formed an...
In this work we provide an update through 2018 of the evolution of changes in the zonal mean vertical distribution of ozone from a number of models participating in the CCMI phase 1 project, using ozone data from the REF-C2 series of simulations. Trends are calculated for the pre- and post-2000 periods, in accordance to the regression analysis and tools presented in the LOTUS SPARC Project and...
In this work, we analyse the seasonal dependence of ozone trends in the stratosphere using four long-term merged datasets: SAGE-CCI-OMPS, SAGE-OSIRIS-OMPS, GOZCARDS and SWOOSH, which provide more than 30 years of monthly zonal mean ozone profiles in the stratosphere. We focus here on trends between 2000 and 2018. All datasets show similar results, although some discrepancies are observed. In...
Reliable ozone trends after 2000 are essential to detect early ozone recovery. However, the long-term ground-based and satellite ozone profile trends reported in the literature show a high variability. In order to determine what part of the variability between different datasets comes from measurement timing, Payerne microwave radiometer (MWR) and chemistry-climate model (SOCOL v 3.0) trends...
Multiple linear regression does a surprisingly good job at reproducing the time series of annual mean total ozone since 1968 at Hohenpeissenberg. Hockey-stick and EESC fit give virtually the same long-term trends: significant decline from 1968 to 1997 and consistent increase from 1998 to now. Recently I also tried the Alsing & Ball DLM model - with very similar long-term variation. In my...
Both stratospheric and tropospheric ozone have changed in concentration over the past few decades and further changes can be expected in the coming decades both as byproducts of human activity and as a result of efforts to limit factors which can affect ozone concentrations. The stratospheric community has been part of an international effort to develop methods of analyzing ozone data for...
The composition of the upper troposphere / lower tratosphere (UTLS) is affected by the Brewer Dobson Circulation (BDC) as well transport across the tropopause and the jets. Since these dynamical processes involve the coupling of transport and mixing processes on very different temporal and spatial scales, long-term changes or even mean distributions from observational data sets on the...
Tropospheric ozone is a greenhouse gas and pollutant detrimental to human health and crop and ecosystem productivity. However, it is difficult to observe and quantify on the global scale, due to its acute spatial variability, resulting from its variable lifetime and its range of sources (injection from the stratosphere, or photochemical production from natural and anthropogenic precursor...
We analyse stratospheric ozone changes due to greenhouse gases and their impact on DNA active UV-B irradiance at ground level. The analysis is an extension of the recent study by Eleftheratos et al. (2020) who showed that solar ultraviolet-B irradiance that produces DNA damage would increase after the year 2050 in mid latitudes by +1.3% per decade. Results were based on chemistry climate model...
