AMT Atmospheric Measurement Techniques AMT Atmos. Meas. Tech. 1867-8548 Copernicus Publications Göttingen, Germany 10.5194/amt-8-1043-2015 A new Dobson Umkehr ozone profile retrieval method optimising information content and resolution Stone K. https://orcid.org/0000-0002-2721-8785 2 1 Tully M. B. https://orcid.org/0000-0002-6153-5610 3 Rhodes S. K. 3 Schofield R. https://orcid.org/0000-0002-4230-717X 1 2 School of Earth Sciences, University of Melbourne, Victoria, 3010, Australia ARC Centre of Excellence for Climate System Science, University of New South Wales, Sydney, New South Wales, 2052, Australia Bureau of Meteorology, Melbourne, Victoria, 3001, Australia 04 03 2015 8 3 1043 1053 Copyright: © 2015 K. Stone et al. 2015 This work is licensed under the Creative Commons Attribution 3.0 Unported License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/3.0/ This article is available from https://amt.copernicus.org/articles/8/1043/2015/amt-8-1043-2015.html The full text article is available as a PDF file from https://amt.copernicus.org/articles/8/1043/2015/amt-8-1043-2015.pdf

The standard Dobson Umkehr methodology to retrieve coarse-resolution ozone profiles used by the National Oceanographic and Atmospheric Administration uses designated solar zenith angles (SZAs). However, some information may be lost if measurements lie outside the designated SZA range (between 60° and 90°), or do not conform to the fitting technique. Also, while Umkehr measurements can be taken using multiple wavelength pairs (A, C and D), past retrieval methods have focused on a single pair (C). Here we present an Umkehr inversion method that uses measurements at all SZAs (termed operational) and all wavelength pairs. (Although, we caution direct comparison to other algorithms.) <br><br> Information content for a Melbourne, Australia (38° S, 145° E) Umkehr measurement case study from 28 January 1994, with SZA range similar to that designated in previous algorithms is shown. When comparing the typical single wavelength pair with designated SZAs to the operational measurements, the total degrees of freedom (independent pieces of information) increases from 3.1 to 3.4, with the majority of the information gain originating from Umkehr layers 2 + 3 and 4 (10–20 km and 25–30 km respectively). In addition to this, using all available wavelength pairs increases the total degrees of freedom to 5.2, with the most significant increases in Umkehr layers 2 + 3 to 7 and 9+ (10–40 and 45–80 km). Investigating a case from 13 April 1970 where the measurements extend beyond the 90° SZA range gives further information gain, with total degrees of freedom extending to 6.5. Similar increases are seen in the information content. Comparing the retrieved Melbourne Umkehr time series with ozonesondes shows excellent agreement in layers 2 + 3 and 4 (10–20 and 25–30 km) for both C and A + C + D-pairs. Retrievals in layers 5 and 6 (25–30 and 30–35 km) consistently show lower ozone partial column compared to ozonesondes. This is likely due to stray light effects that are not accounted for in the forward model, and under represented stratospheric aerosol.

 References Bass, A. M. and Paur, R. J.: The ultraviolet cross-sections of ozone: I. The measurements, in: Atmospheric Ozone, edited by: Zerefos, C. S. and Ghazi, A., Reidal, 606–610, 1985. Bucholtz, A.: Rayleigh-scattering calculations for the terrestrial atmosphere, Appl. Optics, 34, 2765–2773, 1995. Daumont, D., Brion, J., Charbonnier, J., and Malicet, J.: Ozone UV spectroscopy I: Absorption cross-sections at room temperature, J. Atmos. Chem., 15, 145–155, 1992. Dave, J. V.: Development of Programs for Computing Characteristics of Ultraviolet Radiation, Technical report – Vector Case, Federal Systems Div., International Business Machines Corp, Gaithersburg, MD, 1972a. Dave, J. V.: Development of Programs for Computing Characteristics of Ultraviolet Radiation, Technical report – Scalar Case, Federal Systems Div., International Business Machines Corp, Gaithersburg, MD, 1972b. DeLuisi, J. J., Mateer, C. L., and Bhartia, P. K.: On the correspondence between Standard Umkehr, Short Umkehr, and solar backscattered ultraviolet vertical ozone profiles, J. Geophys. Res., 90, 3845–3849, <a href="http://dx.doi.org/10.1029/JD090iD02p03845">https://doi.org/10.1029/JD090iD02p03845</a>, 1985. Dütsch, H. U.: Vertical ozone distribution from Umkehr observations, Arch. Meteor. Geophy. A, 11, 240–251, 1959. Dütsch, H. U. and Staehelin, J.: Results of the new and old Umkehr algorithm compared with ozone soundings, J. Atmos. Terr. Phys., 54, 557–569, 1992. Gorshelev, V., Serdyuchenko, A., Weber, M., Chehade, W., and Burrows, J. P.: High spectral resolution ozone absorption cross-sections – Part 1: Measurements, data analysis and comparison with previous measurements around 293 K, Atmos. Meas. Tech., 7, 609–624, <a href="http://dx.doi.org/10.5194/amt-7-609-2014">https://doi.org/10.5194/amt-7-609-2014</a>, 2014. Gotz, F., Meetham, A. R., and Dobson, G. B.: The vertical distribution of ozone in the atmosphere, Proc. R. Soc. Lon. Ser.-A, 145, 416–446, 1934. Harris, N., Hudson, R., and Phillips, C.: SPARC/IOC/GAW Assessment of Trends in the Vertical Distribution of Ozone, World Climate Research Program of WMO/ICSU, 289 pp., 1998. Hassler, B., Bodeker, G. E., and Dameris, M.: Technical Note: A new global database of trace gases and aerosols from multiple sources of high vertical resolution measurements, Atmos. Chem. Phys., 8, 5403–5421, <a href="http://dx.doi.org/10.5194/acp-8-5403-2008">https://doi.org/10.5194/acp-8-5403-2008</a>, 2008. Hassler, B., Bodeker, G. E., Cionni, I., and Dameris, M.: A vertically resolved, monthly mean, ozone database from 1979 to 2100 for constraining global climate model simulations, Int. J. Remote Sens., 30, 4009–4018, 2009. Hendrick, F., Barret, B., Van Roozendael, M., Boesch, H., Butz, A., De Mazière, M., Goutail, F., Hermans, C., Lambert, J.-C., Pfeilsticker, K., and Pommereau, J.-P.: Retrieval of nitrogen dioxide stratospheric profiles from ground-based zenith-sky UV-visible observations: validation of the technique through correlative comparisons, Atmos. Chem. Phys., 4, 2091–2106, <a href="http://dx.doi.org/10.5194/acp-4-2091-2004">https://doi.org/10.5194/acp-4-2091-2004</a>, 2004. Hendrick, F., Van Roozendael, M., Kylling, K., Petritoli, A., Rozanov, A., Sanghavi, S., Schofield, R., von Friedeburg, D., Wagner, T., Wittrock, F., Fonteyn, D., and De Mazière, M.: Intercomparison excercise between differnt radiative transfer models used for the interpretation of ground-based zenith-sky and multi-axis DOAS observations, Atmos. Chem. Phys., 6, 94–108, <a href="http://dx.doi.org/10.5194/acp-6-93-2006">https://doi.org/10.5194/acp-6-93-2006</a>, 2006. Mateer, C. L.: A Study of the Information Content of Umkehr Observations, Ph.D. thesis, University of Michigan, 4–8, 1964. Mateer, C. L. and DeLuisi, J. J.: A new Umkehr inversion algorithm, J. Atmos. Terr. Phys., 54, 537–556, 1992. Mateer, C. L. and Dütsch, H. U.: Uniform Evaluation of Umkehr Observations from the World Ozone Network, Tech. Rep., Boulder, CO, 150 pp., 1964. Mateer, C. L., Dütsch, H. U., Staehelin, J., and DeLuisi, J. J.: Influence of a priori profiles on trend calculations from Umkehr data, J. Geophys. Res., 101, 16779–16787, 1996. McElroy, C. T. and Kerr, J. B.: Table mountain ozone intercomparison: Brewer ozone spectrophotometer Umkehr observations, J. Geophys. Res., 100, 9293–9300, 1995. Miyagawa, K., Sasaki, T., Nakane, H., Petropavlovskikh, I., and Evans, R. D.: Reevaluation of long-term Umkehr data and ozone profiles at Japanese stations, J. Geophys. Res., 114, D07108, <a href="http://dx.doi.org/10.1029/2008JD010658">https://doi.org/10.1029/2008JD010658</a>, 2009. Newchurch, M. J., Bishop, L., Cunnold, D., Flynn, L. E., Godin, S., Frith, S. H., Hood, L., Miller, A. J., Oltmans, S., Randel, W., Reinsel, G., Stolarski, R., Wang, R., Yang, E.-S., and Zawodny, J. M.: Upper-stratospheric ozone trends 1979–1998, J. Geophys. Res., 105, 14625–14636, 2000. Petropavlovskikh, I., Bhartia, P. K., and DeLuisi, J.: An improved Umkehr algorithm, NOAA Cooperative Institute for Research in Environmental Sciences, 10–15, 2004. Petropavlovskikh, I., Bhartia, P. K., and DeLuisi, J.: New Umkehr ozone profile retrieval algorithm optimized for climatological studies, Geophys. Res. Lett., 32, L16808, <a href="http://dx.doi.org/10.1029/2005GL023323">https://doi.org/10.1029/2005GL023323</a>, 2005. Petropavlovskikh, I., Evans, R., McConville, G., Oltmans, S., Quincy, D., Lantz, K., Disterhoft, P., Stanek, M., and Flynn, L.: Sensitivity of Dobson and Brewer Umkehr ozone profile retrievals to ozone cross-sections and stray light effects, Atmos. Meas. Tech., 4, 1841–1853, <a href="http://dx.doi.org/10.5194/amt-4-1841-2011">https://doi.org/10.5194/amt-4-1841-2011</a>, 2011. Reinsel, G. C.: Trend analysis of upper stratospheric Umkehr ozone data for evidence of turnaround, Geophys. Res. Lett., 29, 91-1–91-4, 2002. Reinsel, G. C., Tiao, G. C., Miller, A. J., Nagatani, R. M., Wuebbles, D. J., Weatherhead, E. C., Cheang, W. K., Zhang, L., Flynn, L. E., and Kerr, J. B.: Update of Umkehr ozone profile data trend analysis through 1997, J. Geophys. Res., 104, 23881–23898, 1999. Rodgers, C. D.: Retrieval of atmospheric temperature and composition from remote measurements of thermal radiation, Rev. Geophys., 14, 609–624, 1976. Rodgers, C. D.: Characterization and error analysis of profiles retrieved from remote sounding measurements, J. Geophys. Res., 95, 5587–5595, 1990. Rodgers, C. D.: Inverse Methods for Atmopsheric Sounding: Theory and Practice, 2nd edn., World Science, Hackensack, NJ, 2000. Rodgers, C. D. and Conner, B. J.: Intercomparison of remote sounding instruments, J. Geophys. Res., 108, 4116, <a href="http://dx.doi.org/10.1029/2002JD002299">https://doi.org/10.1029/2002JD002299</a>, 2003. Schofield, R., Connor, B. J., Kreher, K., Johnston, P. V., and Rodgers, C. D.: The retrieval of profile and chemical information from ground-based UV-visible spectroscopic measurements, J. Quant. Spectrosc. Ra., 86, 115–131, 2004a. Schofield, R., Kreher, K., Conner, B. J., Johnston, A., Thomas, A., Shooter, D., Chipperfield, M. P., Rodgers, C. D., and Mount, G. H.: Retrieved tropospheric and stratospheric BrO columns over Lauder, New Zealand, J. Geophys. Res., 109, D14304, <a href="http://dx.doi.org/10.1029/2003JD004463">https://doi.org/10.1029/2003JD004463</a>, 2004b. Solomon, S., Schmeltekopf, A. L., and Sanders, R. W.: On the interpretation of zenith sky absorption measurements, J. Geophys. Res., 92, 8311–8319, 1987.