Northern middle‐latitude ozone profile features and trends observed by SBUV and Umkehr, 1979–1990

Abstract

A comparison of Umkehr ozone profile data with the reprocessed solar backscatter ultraviolet (SBUV) ozone profile data in the northern middle-latitude region, 30 ø to 50øN, is reported. Although significant biases exist between the two types of observations, the long-term variations and least squares linear regression trends agree remarkably well over the comparison period of 1979 to 1990. The ozone trend in the upper stratosphere is of the order of -0.9% yr -1 . Near 25 km, little if any trend appears, but a larger negative trend is seen in the lower stratosphere near 15 km. Comparisons show that the average annual ozone cycles in the profiles also agree well. The upper stratospheric ozone results are consistent with photochemical model predictions of ozone depletion near 40 km that are due to the release of anthropogenically produced chlorofluorocarbons. The lower stratospheric ozone trend results are in reasonable agreement with published ozonesonde data trends. It is shown that the ozone trends in the lower stratospheric layers impact significantly on the total ozone trend of the order of • -0.47% yr-. The good agreement now seen between the two types of observations suggests that the combined ground-based and satellite approach could provide a valuable database for long-term monitoring of stratospheric ozone for trends and extraordinary variations. Paper number 94JD01518. 0148-0227/94/94JD0-1518505.00 in both. The cause was attributed to a degradation of the diffuser plate that is used to obtain a solar reference observation [Fleig et al., 1981]. The Dobson network has been active up to the present; however, some stations were voluntarily terminated and others were added as time passed. Also, not all stations made U mkehr observations. The network underwent a rapid increase in size about the beginning of 1962 after the World Meteorological Organization (WMO) urged members countries to start ozoneobserving programs. A few stations, including Arosa, Switzerland, and Oxford, England, were operating before the IGY. International data collection and publication by the WMO started with the IGY. Fortunately, a long-term record of total ozone and Umkehr ozone profile data has now been accumulated because of the persistent efforts of the WMO 18,901 18,902 DELUISI ET AL.: OZONE PROFILE FEATURES AND TRENDS, ß [ ß , ß ! ß , ß • ß [ ß , ß T ß [ ß T ß ,

Influence of a priori profiles on trend calculations from Umkehr data

“…It appears that this level shift is real; it is also seen by SBUV and at other Umkehr stations [DeLuisi et al, 1994]. Figure tt displays the Umkehr trends with and without haze corrections.…”

Statistical interpolation of ozone measurements from satellite data (TOMS, SBUV and SAGE II) using the kriging method

“…Comparisons of ozone pro®les between SBUV and SAGE II (Stratospheric Aerosol and Gas Experiments), which has better vertical resolution but poorer horizontal resolution, have been conducted by McPeters et al (1994), and they attest to the high quality of SBUV ozone pro®les. Good agreement between SBUV and the Umkehr mean pro®les from ®ve stations in the Northern Hemisphere has been found by De Luisi et al (1994). Recently, it has been shown that the SBUV instrument can capture large-scale variability in ozone over a broad range of atmospheric pressures (0.3± 100 mbar) .…”

“…Firstly, many comparisons have been made with ground measurements (De Luisi et al, 1994;McPeters et al, 1994) and these report that the SBUV dataset provides good results. Secondly, SBUV provides the best horizontal resolution among the available datasets, and also provides vertical pro®les.…”

Retrieving vertical ozone profiles from measurements of global spectral irradiance

“…For midlatitude sites, Brewer Umkehr data have a precision of about 15 % in the 20 to 40 km region, with larger departures outside this altitude range (McElroy and Kerr, 1995). Umkehr data are routinely used for monitoring the drift of sensors measuring the vertical distribution of ozone from space (Newchurch et al, 1987;DeLuisi et al, 1994;Miller et al, 1997;Krzyścin et al, 2009;Petropavlovskikh et al, 2005.…”