11 Aug 2023
 | 11 Aug 2023
Status: a revised version of this preprint was accepted for the journal AMT.

Version 8 IMK/IAA MIPAS measurements of CFC-11, CFC-12, and HCFC-22

Gabriele P. Stiller, Thomas von Clarmann, Norbert Glatthor, Udo Grabowski, Sylvia Kellmann, Michael Kiefer, Alexandra Laeng, Andrea Linden, Bernd Funke, Maya Garcia-Comas, and Manuel Lopez-Puertas

Abstract. The Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) on Envisat provided infrared limb emission spectra, which were used to infer global distributions of CFC-11, CFC-12, and HCFC-22. Spectra were analysed using constrained non-linear least squares fitting. Changes with respect to earlier data versions refer to the use of version 8 spectra, the altitude range where the background continuum is considered, details of the regularisation and microwindow selection, and the occasional joint-fitting of interfering species, new spectroscopic data, the joint-fit of a tangent-height dependent spectral offset, and the use of 2D temperature fields. In the lower stratosphere the error budget is dominated by uncertainties in spectroscopic data, while above measurement noise is the leading error source. The vertical resolution of CFC-11 and CFC-12 is 2–3 km near the tropopause, about 4 km at 30 km altitude and 6–10 km at 50 km. The vertical resolution of HCFC-22 is somewhat coarser, 3–4 km at the tropopause and 10–12 km at 35 km altitude. In the altitude range of interest, the horizontal resolution is typically limited by the horizontal sampling of the measurements, not by the smearing of the retrieval. Horizontal information displacement does not exceed 150 km, which can become an issue only for comparisons with model simulations with high horizontal resolution or localised in-situ observations. Along with the regular data product, an alternative representation of the data on a coarser vertical grid is offered. These data can be used without consideration of the averaging kernels. The new data version provides improvement with respect to reduction of biases and improved consistency between the full and reduced resolution mission period of MIPAS.

Gabriele P. Stiller et al.

Status: final response (author comments only)

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on amt-2023-172', Anonymous Referee #1, 01 Sep 2023
  • RC2: 'Comment on amt-2023-172', Anonymous Referee #2, 11 Sep 2023

Gabriele P. Stiller et al.

Gabriele P. Stiller et al.


Total article views: 363 (including HTML, PDF, and XML)
HTML PDF XML Total Supplement BibTeX EndNote
244 95 24 363 19 14 13
  • HTML: 244
  • PDF: 95
  • XML: 24
  • Total: 363
  • Supplement: 19
  • BibTeX: 14
  • EndNote: 13
Views and downloads (calculated since 11 Aug 2023)
Cumulative views and downloads (calculated since 11 Aug 2023)

Viewed (geographical distribution)

Total article views: 347 (including HTML, PDF, and XML) Thereof 347 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
Latest update: 06 Dec 2023
Short summary
CFC-11, CFC-12, and HCFC-22 contribute to the depletion of ozone and are potent greenhouse gases. They have been banned by the Montreal protocol. With MIPAS on Envisat the atmospheric composition could be observed between 2002 and 2012. We present here the retrieval of their atmospheric distributions for the final data version 8. We characterise the derived data by their error budget and their spatial resolution. An additional representation for direct comparison to models is also provided.