Stratospheric ozone variation induced by the 11-year solar cycle: Recent 22-year simulation using 3-D chemical transport model with reanalysis data (original) (raw)
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We have used an off-line 3-D chemical transport model (CTM) to investigate the 11-yr solar cycle response in tropical stratospheric ozone. The model is forced with European Centre for Medium-Range Weather Forecasts (ECMWF) (re)analysis (ERA-40/operational and ERA-Interim) data for the 1979-2005 time period. We have compared the modelled solar response in ozone to observationbased data sets that are constructed using satellite instruments such as Total Ozone Mapping Spectrometer (TOMS), Solar Backscatter UltraViolet instrument (SBUV), Stratospheric Aerosol and Gas Experiment (SAGE) and Halogen Occultation Experiment (HALOE). A significant difference is seen between simulated and observed ozone during the 1980s, which is probably due to inhomogeneities in the ERA-40 reanalyses. In general, the model with ERA-Interim dynamics shows better agreement with the observations from 1990 onwards than with ERA-40. Overall both standard model simulations are partially able to simulate a "double peak"-structured ozone solar response with a minimum around 30 km, and these are in better agreement with HALOE than SAGE-corrected SBUV (SBUV/SAGE) or SAGE-based data sets. In the tropical lower stratosphere (TLS), the modelled solar response with time-varying aerosols is amplified through aliasing with a volcanic signal, as the model overestimates ozone loss during high aerosol loading years. However, the modelled solar response with fixed dynamics and constant aerosols shows a positive signal which is in better agreement with SBUV/SAGE and SAGE-based data sets in the TLS. Our model simulations suggests that photochemistry contributes to the ozone solar response in this region. The largest model-observation differences occur in the upper stratosphere where SBUV/SAGE and SAGE-based data show a significant (up to 4 %) solar
Journal of geomagnetism and geoelectricity, 1991
Trend analyses of satellite and ground-based observations clearly indicate that temperatures and ozone concentrations in the upper stratosphere are undergoing longterm changes. Variations in solar ultraviolet radiation during the 11-year solar cycle are influencing stratospheric temperatures and photochemistry from above. Forcings from below result from the increasing atmospheric concentrations of long-lived trace constituents, such as carbon dioxide, methane, nitrous oxide, several chlorofluorocarbons and other halocarbons. Using the LLNL two-dimensional chemicalradiative-transport model of the global atmosphere, we evaluate the influences of these external forcings on the middle atmosphere. Our calculations include recent estimates of the variations in solar ultraviolet radiation since 1974. Model results for the solar cycle effects on total ozone, upper stratospheric ozone and temperature are within the uncertainty (in some cases, large) range of observational data analyses. The model calculations including both solar variability and the effects of changing trace gas emissions can explain much of the observed trends in upper stratospheric ozone and temperature from 1979 to 1986.
Long-term response of stratospheric ozone and temperature to solar variability
Annales Geophysicae, 2015
The long-term variability in stratospheric ozone mass mixing ratio (O 3) and temperature (T) from 1979 to 2013 is investigated using the latest reanalysis product delivered by the European Centre for Medium-Range Weather Forecasts (ECMWF), i.e., ERA-Interim. Moreover, using the Mg II index time series for the same time period, the response of the stratosphere to the 11-year Schwabe solar cycle is investigated. Results reveal the following features: (i) upward (downward) trends characterize zonally averaged O 3 anomalies in the upper (middle to lower stratosphere) stratosphere, while prevailing downward trends affect the T field. Mg II index data exhibit a weaker 24th solar cycle (though not complete) when compared with the previous two; (ii) correlations between O 3 and Mg II, T and Mg II, and O 3 and T are consistent with photochemical reactions occurring in the stratosphere and large-scale transport; and (iii) wavelet cross-spectra between O 3 and Mg II index show common power for the 11-year period, particularly in tropical regions around 30-50 hPa, and different relative phase in the upper and lower stratosphere. A comprehensive insight into the actual processes accounting for the observed correlation between ozone and solar UV variability would be gained from an improved bias correction of ozone measurements provided by different satellite instruments, and from the observations of the time behavior of the solar spectral irradiance.
Advances in Space Research, 2001
Results are presented from two-year simulations of the effects of short-term solar ultraviolet (UV) variability using the Met. Office coupled chemistry-climate model. The model extends from the ground to 0.1 mbar and contains a complete range of chemical reactions allowing representation of all the main ozone formation and destruction processes in the stratosphere. The simulations were achieved by incorporating a 27-day oscillation in the pre-calculated model photolysis rates. Amplitudes for this signal were determined using solar spectral UV observations from the SOLar STellar Irradiance Comparison Experiment (SOLSTICE) instrument. Two experiments were carried out, one in which the UV variability was included in both the photolysis and radiation schemes and one in which only the photolysis scheme was modified. The model reproduced several main features of observed correlations between short-term solar UV variability and both ozone and temperature in the tropical upper stratosphere, including the downward propagation of the phase lag and sensitivities of ozone and temperature to solar UV which are similar in magnitude to those observed. In the lower stratosphere, the ozone response to solar UV variability has not been well characterised from observations. Both model runs show a reversal of the propagation of phase lag below 1Omb. The model response was found to be different between the two runs indicating that radiatively induced dynamical effects may play a significant role in the ozone response to solar W variability.
Journal of Geophysical Research, 2006
1] Previous multiple regression analyses of the solar cycle variation of stratospheric ozone are improved by (1) analyzing three independent satellite ozone data sets with lengths extending up to 25 years and (2) comparing column ozone measurements with ozone profile data during the 1992-2003 period when no major volcanic eruptions occurred. Results show that the vertical structure of the tropical ozone solar cycle response has been consistently characterized by statistically significant positive responses in the upper and lower stratosphere and by statistically insignificant responses in the middle stratosphere ($28-38 km altitude). This vertical structure differs from that predicted by most models. The similar vertical structure in the tropics obtained for separate time intervals (with minimum response invariably near 10 hPa) is difficult to explain by random interference from the QBO and volcanic eruptions in the statistical analysis. The observed increase in tropical total column ozone approaching the cycle 23 maximum during the late 1990s occurred primarily in the lower stratosphere below the 30 hPa level. A mainly dynamical origin for the solar cycle total ozone variation at low latitudes is therefore likely. The amplitude of the solar cycle ozone variation in the tropical upper stratosphere derived here is somewhat reduced in comparison to earlier results. Additional data are needed to determine whether this upper stratospheric response is or is not larger than model estimates. Citation: Soukharev, B. E., and L. L. Hood (2006), Solar cycle variation of stratospheric ozone: Multiple regression analysis of longterm satellite data sets and comparisons with models,
The Middle Atmospheric Ozone Response to the 11-Year Solar Cycle
Space Science Reviews, 2007
Because of its chemical and radiative properties, atmospheric ozone constitutes a key element of the Earth's climate system. Absorption of sunlight by ozone in the ultraviolet wavelength range is responsible for stratospheric heating, and determines the temperature structure of the middle atmosphere. Changes in middle atmospheric ozone concentrations result in an altered radiative input to the troposphere and to the Earth's surface, with implications on the energy balance and the chemical composition of the lower atmosphere. Although a wide range of ground-and satellite-based measurements of its integrated content and of its vertical distribution have been performed since several decades, a number of uncertainties still remain as to the response of middle atmospheric ozone to changes in solar irradiance over decadal time scales. This paper presents an overview of achieved findings, including a discussion of commonly applied data analysis methods and of their implication for the obtained results. We suggest that because it does not imply least-squares fitting of prescribed periodic or proxy data functions into the considered times series, time-domain analysis provides a more reliable method than multiple regression analysis for extracting decadal-scale signals from observational ozone datasets. Applied to decadal ground-based observations, time-domain analysis indicates an average middle atmospheric ozone increase of the order of 2% from solar minimum to solar maximum, which is in reasonable agreement with model results.
Atmospheric Chemistry and Physics Discussions, 2008
Three analyses of satellite observations and two sets of model studies are used to estimate changes in the stratospheric ozone distribution from solar minimum to solar maximum and are presented for three different latitudinal bands: Poleward of 30 • north, between 30 • north and 30 • south and poleward of 30 • south. In the model studies the 5 solar cycle impact is limited to changes in UV fluxes. There is a general agreement between satellite observation and model studies, particular at middle and high northern latitudes. Ozone increases at solar maximum with peak values around 40 km. The profiles are used to calculate the radiative forcing (RF) from solar minimum to solar maximum. The ozone RF, calculated with two different radiative transfer schemes is 10 found to be negligible (a magnitude of 0.01 Wm −2 or less), compared to the direct RF due to changes in solar irradiance, since contributions from the longwave and shortwave nearly cancel each other. The largest uncertainties in the estimates come from the lower stratosphere, where there is significant disagreement between the different ozone profiles. 15 25 impact of this change in ozone, however, is uncertain. There are significant differences 4354 Abstract 25 (Houghton et al., 2001). Abstract 25 4359 ACPD 8, 4353-4371, 2008 Abstract the lower stratosphere, where ozone perturbations have the strongest impact on the 4360 ACPD 8,[4353][4354][4355][4356][4357][4358][4359][4360][4361][4362][4363][4364][4365][4366][4367][4368][4369][4370][4371] 2008 Abstract 25 extending the calculations down to 20 km has, as expected, more of an effect on the LW forcing, and causes the net forcing to change in sign from negative to positive ; it, however, remains small. 4363 Abstract References Bian, H. S. and Prather, M. J.: Fast-J2: Accurate simulations of stratospheric photolysis in 25 global chemistry models,
Coupled chemistry climate model simulations of the solar cycle in ozone and temperature
2008
The 11-year solar cycles in ozone and temperature are examined using new simulations of coupled chemistry climate models. The results show a secondary maximum in stratospheric tropical ozone, in agreement with satellite observations and in contrast with most previously published simulations. The mean model response varies by up to about 2.5% in ozone and 0.8 K in temperature during a typical solar cycle, at the lower end of the observed ranges of peak responses. Neither the upper atmospheric effects of energetic particles nor the presence of the quasi biennial oscillation is necessary to simulate the lower stratospheric response in the observed low latitude ozone concentration. Comparisons are also made between model simulations and observed total column ozone. As in previous studies, the model simulations agree well with observations. For those models which cover the full temporal range 1960-2005, the ozone solar signal below 50 hPa changes substantially from the first two solar cycles to the last two solar cycles. Further investigation suggests that this difference is due to an aliasing between the sea surface temperatures and the solar cycle during the first part of the period. The relationship between these results and the overall structure in the tropical solar ozone response is discussed. Further understanding of solar processes requires improvement in the observations of the vertically varying and column integrated ozone.
Atmospheric Chemistry and Physics, 2013
Solar spectral fluxes (or irradiance) measured by the SOlar Radiation and Climate Experiment (SORCE) show different variability at ultraviolet (UV) wavelengths compared to other irradiance measurements and models (e.g. NRL-SSI, SATIRE-S). Some modelling studies have suggested that stratospheric/lower mesospheric O 3 changes during solar cycle 23 (1996)(1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008) can only be reproduced if SORCE solar fluxes are used. We have used a 3-D chemical transport model (CTM), forced by meteorology from the European Centre for Medium-Range Weather Forecasts (ECMWF), to simulate middle atmospheric O 3 using three different solar flux data sets (SORCE, NRL-SSI and SATIRE-S). Simulated O 3 changes are compared with Microwave Limb Sounder (MLS) and Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) satellite data. Modelled O 3 anomalies from all solar flux data sets show good agreement with the observations, despite the different flux variations. The off-line CTM reproduces these changes through dynamical information contained in the analyses. A notable feature during this period is a robust positive solar signal in the tropical middle stratosphere, which is due to realistic dynamical changes in our simulations. Ozone changes in the lower mesosphere cannot be used to discriminate between solar flux data sets due to large uncertainties and the short time span of the observations. Overall this study suggests that, in a CTM, the UV variations detected by SORCE are not necessary to reproduce observed stratospheric O 3 changes during 2001-2010.
Attribution of stratospheric ozone trends to chemistry and transport: a modelling study
Atmospheric Chemistry and Physics, 2010
The decrease of the concentration of ozone depleting substances (ODS) in the stratosphere over the past decade raises the question to what extent observed changes in stratospheric ozone over this period are consistent with known changes in chemical composition and possible changes in atmospheric transport. Here we present a series 5 of ozone sensitivity calculations with a stratospheric chemistry transport model (CTM) driven with meteorological reanalyses from the European Centre for Medium Range Weather Forecast, covering the period 1978-2009. In order to account for the reversal in ODS trends, ozone trends are analysed in two periods, 1979-1999 and 2000-2009. Effects of ODS changes on the ozone chemistry are either accounted for or left out, 10 allowing for a distinct attribution of ozone trends to the different factors of variability, namely ODS acting via gas phase chemistry, ODS acting via polar heterogeneous chemistry, and changes in transport and temperature. Modeled column ozone trends are in excellent agreement with observed trends from the Total Ozone Mapping Spectrometer (TOMS) and Solar Backscatter UV (SBUV/2) as well as the Global Ozone