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Overview Algorithm Data Access

Umkehr ozone profiles from Dobson measurements


For Brewer Umkehr measurements please see the NEUBrew web page.


The Umkehr is an observational method designed to collect zenith sky observations at two UV wavelengths during sunrise or sunset time. An optimal estimation technique is used for retrieving the vertical profile of ozone from ultraviolet radiation collected by Dobson spectrophotometer instruments at wavelengths centered at 311.5 and 332.4 nm. The Brewer ozone profiles are retrieved using similar techniques with ZS observations at ~310 and ~326 nm). The longest time series of ozone profiles derived using the Umkehr technique are found with the combined Arosa/Davos Dobson records (since 1935). At NOAA Dobson network, Umkehrs have been measured at 6 stations for over forty-five years using the Dobson ozone spectrophotometer.



Map of Umkehr ozone profile sites

Site Code Short Name Long Name Latitude Longitude Elevation Institute(s)
ARO Arosa Combined record of the Arosa and Davos 46.78N 9.67E 2500 m MeteoSwiss
Davos observatories, Switzerland 46.81N 9.84E 1590 m
BLD Boulder Boulder, CO, USA 40.02N 105.26W 1634 m NOAA
FBK Fairbanks Faribanks, AK, USA 64.86N 147.85W 133 m NOAA
University of Alaska - Faribanks
LAU Lauder Lauder, New Zealand 45.04S 169.68E 370 m NIWA
NOAA
OHP Haute-Provance Observatoire de Haute-Provence, France 43.92N 5.71E 650 m University of Reims
NOAA
PTH Perth Perth, Australia 31.92S 115.97E 5 m Bureau of Meteorology
NOAA

Trends

Trends of Umkehr ozone profile sites
Trends in the vertical profile of ozone from five Umkehr stations using the Long-Term Ozone Trends and Uncertainties in the Stratosphere (LOTUS) model. This figure is adapted from the model used in (Petropavlovskikh 2025). The trends are broken into two time periods: Ozone depletion period (orange) which goes from the start of the record (*1982 is shown in the plot label, but 1982 is just the average start year) to 1997. The Ozone recovery period is from 2000-2023 (blue).

  • Petropavlovskikh, I., Wild, J. D., Abromitis, K., Effertz, P., Miyagawa, K., Flynn, L. E., Maillard Barras, E., Damadeo, R., McConville, G., Johnson, B., Cullis, P., Godin-Beekmann, S., Ancellet, G., Querel, R., Van Malderen, R., and Zawada, D.: Ozone trends in homogenized Umkehr, ozonesonde, and COH overpass records, Atmos. Chem. Phys., 25, 2895–2936, https://doi.org/10.5194/acp-25-2895-2025, 2025

Contact:


Irina Petropavlovski
irina.petro@noaa.gov

Peter Effertz
peter.effertz@noaa.gov

Glen McConville
glen.mcconville@noaa.gov