The GOME-type Total Ozone Essential Climate Variable (GTO-ECV) data record from the ESA Climate Change Initiative

摘要

We present the new GOME-type Total Ozone Essential Climate Variable (GTO-ECV) data recordwhich has been created within the framework of the European Space Agency's Climate ChangeInitiative (ESA-CCI). Total ozone column observations – based on the GOME-type Direct Fittingversion 3 algorithm – from GOME (Global Ozone Monitoring Experiment), SCIAMACHY (SCanningImaging Absorption SpectroMeter for Atmospheric CHartographY), and GOME-2 have been combinedinto one homogeneous time series, thereby taking advantage of the high inter-sensor consistency.The data record spans the 15-year period from March 1996 to June 2011 and it contains globalmonthly mean total ozone columns on a 1°× 1° grid.Geophysical ground-based validation using Brewer, Dobson, and UV–visible instrumentshas shown that the GTO-ECV level 3 data record is of the same high quality as the equivalent individuallevel 2 data products that constitute it. Both absolute agreement and long-term stabilityare excellent with respect to the ground-based data, for almost all latitudes apart from afew outliers which are mostly due to sampling differences between the level 2 and level 3 data.We conclude that the GTO-ECV data record is valuable for a variety of climate applications suchas the long-term monitoring of the past evolution of the ozone layer, trend analysisand the evaluation of chemistry–climate model simulations.