Construction of merged satellite total O<sub>3</sub> and NO<sub>2</sub> time series in the tropics for trend studies and evaluation by comparison to NDACC SAOZ measurements

Abstract

Abstract. Long time series of ozone and NO 2 total column measurements in the southern tropics are available from two ground-based SAOZ (Système d'Analyse par Observation Zénithale) UV-visible spectrometers operated within the Network for the Detection of Atmospheric Composition Change (NDACC) in Bauru (22 • S, 49 • W) in S-E Brazil since 1995 and Reunion Island (21 • S, 55 • E) in the S-W Indian Ocean since 1993. Although the stations are located at the same latitude, significant differences are observed in the columns of both species, attributed to differences in tropospheric content and equivalent latitude in the lower stratosphere. These data are used to identify which satellites operating during the same period, are capturing the same features and are thus best suited for building reliable merged time series for trend studies. For ozone, the satellites series best matching SAOZ observations are EP-TOMS (1995 and OMI-TOMS (2005-2011, whereas for NO 2 , best results are obtained by combining GOME version GDP5 (1996GDP5 ( -2003 and SCIA-MACHY -IUP (2003-2011, displaying lower noise and seasonality in reference to SAOZ. Both merged data sets are fully consistent with the larger columns of the two species above South America and the seasonality of the differences between the two stations, reported by SAOZ, providing reliable time series for further trend analyses and identification of sources of interannual variability in the future analysis.

Russian National Report: Meteorology and Atmospheric Sciences

“…The June minimum in the annual variation of aerosol concentration (for 0.02-1 µm size spectrum) is also observed in Moscow area [20], and the December maximum (along with two secondary ones in spring and late summer) in Tomsk area [128]. Apart from the annual cycle, a diurnal one for aerosol characteristics has been distinguished for Siberian cities [134] and Moscow area [135] based on observations. According to [145], not only a diurnal cycle, but also the so-called 'weekend effect' is observed over such a megacity as London.…”

“…New estimates of climatic effects have been obtained with the use of new parameterizations and specially developed algorithms for description of comprehensive climate processes [127][128][129][130][131][132][133][134][135][136]182]. In particular, the ionospheric potential parameterization was used in the general circulation model of the atmosphere and ocean [182].…”

“…Spatiotemporal aerosol characteristics (aerosol optical thickness, AOT; microphysical properties) have been investigated for different regions of Russia and other countries [128][129][130][131][132][133][134][135][136][137][138][139][140][141][142][143][144][145], including polar regions [146][147][148][149][150][151][152][153][154][155], and sea regions [156][157][158][159][160]. In papers [161][162][163][164][165], chemical aerosol properties, including ion composition, have been studied.…”

“…Climate models development is related with the more detailed resolution with inclusion of additional effects and climate processes and also with the more adequate simulation of interaction between different components of the climate system [128][129][130][131][132][133][134][135][136].…”

Impact of inter-mission differences and drifts on chlorophyll-atrend estimates

“…In the studies cited above, intermission biases were handled in a variety of ways, from ignoring them in the temporal analyses to specifically accounting for them, or correcting them. These issues have been faced by other disciplines that have developed responses adapted to the characteristics associated with the variable under study, for instance, sea level (Ablain et al 2015), sea surface temperature (Kilpatrick, Podestà, and Evans 2001), or atmospheric ozone (Lerot et al 2014;Pastel et al 2014).…”