Comparison and synergy of stratospheric ozone measurements by satellite limb sounders and the ground-based microwave radiometer SOMORA

Abstract

Abstract.Stratospheric O 3 profiles obtained by the satellite limb sounders Aura/MLS, ENVISAT/MIPAS, EN-VISAT/GOMOS, SAGE-II, SAGE-III, UARS/HALOE are compared to coincident O 3 profiles of the ground-based microwave radiometer SOMORA in Switzerland. Data from the various measurement techniques are within 10% at altitudes below 45 km. At altitudes 45-60 km, the relative O 3 differences are within a range of 50%. Larger deviations at upper altitudes are attributed to larger relative measurement errors caused by lower O 3 concentrations. The spatiotemporal characteristics of the O 3 differences (satelliteground station) are investigated by analyzing about 2300 coincident profile pairs of Aura/MLS (retrieval version 1.5) and SOMORA. The probability density function of the O 3 differences is represented by a Gaussian normal distribution. The dependence of the O 3 differences on the horizontal distance between the sounding volumes of Aura/MLS and SOMORA is derived. While the mean bias (Aura/MLS -SOMORA) is constant with increasing horizontal distance (up to 800 km), the standard deviation of the O 3 differences increases from around 8 to 11% in the mid-stratosphere. Geographical maps yield azimuthal dependences and horizontal gradients of the O 3 difference field around the SOMORA ground station. Coherent oscillations of O 3 are present in the time series of Aura/MLS and SOMORA (e.g., due to traveling planetary waves). Ground-and space-based measurements often complement one another. We discuss the double differencing technique which allows both the cross-validation of Correspondence to: K. Hocke (klemens.hocke@mw.iap.unibe.ch) two satellites by means of a ground station and the crossvalidation of distant ground stations by means of one satellite. Temporal atmospheric noise in the geographical ozone map over Payerne is significantly reduced by combination of the data from SOMORA and Aura/MLS. These analyses illustrate the synergy of ground-based and space-based measurements.

Past changes in the vertical distribution of ozone – Part 1: Measurement techniques, uncertainties and availability

“…Other instruments, also listed on the above site, have operated over periods of months to a decade (Table 1c). Instrument and measurement details for Lauder and Mauna Loa were published in Parrish et al (1992), for Payerne in Maillard-Barras et al (2009) and Hocke et al (2007), for Bern in Studer et al (2013), for Ny Ålesund in Palm et al (2010). Data from these instruments are archived on the NDACC webpage (see Table 1d for URL).…”

A climatology of the diurnal variations in stratospheric and mesospheric ozone over Bern, Switzerland

“…GROMOS is part of the Network for the Detection of Atmospheric Composition Change (NDACC), and its data set is used for cross-validation of satellite experiments, studies of ozone-climate interactions and middle atmospheric dynamics, as well as for long-term monitoring of the ozone layer in the stratosphere (Peter and Kämpfer, 1995;Peter et al, 1996;Calisesi et al, 2001;Dumitru et al, 2006;Hocke et al, 2006;Steinbrecht et al, 2006;Hocke et al, 2007;Flury et al, 2009;Steinbrecht et al, 2009;Studer et al, 2012;Hocke et al, 2013).…”

Mid-latitude ozone monitoring with the GOMOS-ENVISAT experiment version 5: the noise issue

“…The intercomparison of ozone profiles from GOMOS and GROMOS is similarly performed as the intercomparison of ozone profiles from GOMOS and the ground-based microwave radiometer SOMORA at Payerne as described by Hocke et al (2007). The high-resolution ozone profiles of GOMOS are adjusted by averaging kernel smoothing to the vertical resolution (about 10 km) of GROMOS.…”