Distribution Of Ozone In Stratosphere Research Articles

Vertical Distribution of Stratospheric Ozone over China

Based on the Stratospheric Aerosol and Gas Experiment (SAGE) II and the Halogen Occultation Experiment (HALOE) ozone profiles and the Total Ozone Mapping Spectrometer (TOMS) total ozone data sets, the characteristics and variations of the vertical distribution of stratospheric ozone covering the latitude bands of 50°N±5°N, 40°N±5°N, 30°N±5°N, and 20°N±5°N and the longitude range of 75–135°E are investigated. The results indicate that the ozone distribution pattern over China not only has general behaviors, but also has particular characteristics. In view of the situation that ozone distributions have substantial deviation from zonal symmetry in northern China, the differences of the vertical ozone distribution between the east and the west part of northern China are studied. The results indicate that during winter, spring, and autumn, in the latitude bands of 50°N±5°N, 40°N±5°N, ozone concentrations in the eastern part (105–135°E) are obviously higher than those of the west (75–105°E) at the altitudes of ozone density maximum and below; during summer, in the latitude band of 50°N±5°N, the east-west ozone profile difference is small, but in the latitude band of 40°N±5°N, the east-west total ozone difference becomes as large as 14.0 DU, and the east-west ozone profile difference mainly exists in the lowermost stratosphere and troposphere.

Examination of the 2002 major warming in the southern hemisphere using ground-based and Odin/SMR assimilated data: stratospheric ozone distributions and tropic/mid-latitude exchange

Following an exceptionally active winter, the 2002 Southern Hemisphere (SH) major warming occurred in late September. It was preceded by three minor warming events that occurred in late August and early September, and yielded vortex split and break-down over Antarctica. Ozone (O3 and nitrous oxide (N2O) profiles obtained during that period of time (15 August – 4 October) by the Sub-Millimetre Radiometer (SMR) aboard the Odin satellite are assimilated into MOCAGE (Modélisation Isentrope du transport Mésoéchelle de l'Ozone Stratosphérique par Advection), a global three-dimensional chemistry transport model of Météo-France. The assimilated algorithm is a three-dimensional-FGAT built by the European Centre for Research and Advance Training in Scientific Computation (CERFACS) using the PALM (Projet d'Assimilation par Logiciel Multi-méthode) software. The assimilated O3 and N2O profiles and isentropic distributions are compared to ground-based measurements (LIDAR and balloon-sonde) and to maps of advected potential vorticity (APV). The latter is computed by the MIMOSA (Modélisation Isentrope du transport Mésoéchelle de l'Ozone Stratosphérique par Advection) model, a high-resolution advection transport model, using meteorological fields from the European Centre for Medium-Range Weather Forecasts (ECMWF). It is found that O3 concentrations retrieved by the MOCAGE–PALM assimilation system show a reasonably good agreement in the 20–28 km height range when compared with ground-based profiles. This altitude range corresponds to the intersection between the MOCAGE levels (0–28 km) and SMR O3 retrievals (20–50 km). Moreover, comparison of N2O assimilated fields with MIMOSA APV maps indicates that the dramatic split and subsequent break-down of the polar vortex, as well as the associated mixing of mid- and low-latitude stratospheric air, are well resolved and pictured by MOCAGE–PALM. The present study demonstrates also that the tremendous dynamics and associated polar vortex deformations during the 2002-austral-winter have modified ozone and nitrous oxide distributions not only at the vicinity of the polar vortex, but over topics and subtropics as well. PACS Nos.: 92.60.H–, 92.60.Hd, 92.70.Cp, 92.70.Gt

Study of the spatio-temporal distribution of stratospheric ozone from millimeter-waves observations for middle and high latitudes

We present the results of simultaneous ozonospheric millimeter-wave observations performed from the Earth’s surface at the middle and high latitudes of the Northern hemisphere in cold seasons of 2002–2005. The observed spatial and temporal variations in the ozone content are described. The features of the vertical ozone distribution inside and outside the polar stratospheric vortex are considered. It is concluded that radiophysical methods are efficient for studying the evolution of the ozonospheric especially under the polar-night conditions.

The 11‐year solar cycle in stratospheric ozone: Comparison between Umkehr and SBUVv8 and effects on surface erythemal irradiance

Ozone profiles derived from ground‐based Umkehr measurements at five stations and from the merged data set of Solar Backscattered Ultra Violet (SBUVv8) satellite observations are used to estimate the seasonal influence of the 11‐year solar signal in the vertical distribution of stratospheric ozone. Both data sets show a strong response (2–3% of the annual mean) in the upper stratosphere, a very small response in the middle tropical stratosphere and a secondary maximum (∼2%) in the tropical lower stratosphere, in accordance to earlier reports. Thus a sequence of high‐low‐high response is seen in the vertical pattern of the solar cycle effect on ozone in the tropics, with its position sensitive to season, as it appears to move across the equator in direction opposite to the location of the maximum solar insolation. Results from Umkehr and satellite observations are in good agreement at levels up to 35 km, while discrepancies (of up to 2%) found at higher levels (around 40 km) are largest in summer. Finally, the estimated erythemal irradiance response to the 11‐year solar cycle, calculated for the observed ozone change during a solar cycle (minimum to maximum), showed an overall decrease in the irradiance at the surface which is maximum (−2% of annual mean) over the tropics.

Dynamic multi-resolution spatial models

Data from remote-sensing platforms play an important role in monitoring environmental processes, such as the distribution of stratospheric ozone. Remote-sense data are typically spatial, temporal, and massive. Existing prediction methods such as kriging are computationally infeasible. The multi-resolution spatial model (MRSM) captures nonstationary spatial dependence and produces fast optimal estimates using a change-of-resolution Kalman filter. However, past data can provide valuable information about the current status of the process being investigated. In this article, we incorporate the temporal dependence into the process by developing a dynamic MRSM. An application of the dynamic MRSM to a month of daily total column ozone data is presented, and on a given day the results of posterior inference are compared to those for the spatial-only MRSM. It is apparent that there are advantages to using the dynamic MRSM in regions where data are missing, such as when a whole swath of satellite data is missing.

Nighttime ozone profiles in the stratosphere and mesosphere by the Global Ozone Monitoring by Occultation of Stars on Envisat

The Global Ozone Monitoring by Occultation of Stars (GOMOS) instrument on board the European Space Agency's Envisat satellite measures ozone and a few other trace gases using the stellar occultation method. Global coverage, good vertical resolution and the self‐calibrating measurement method make GOMOS observations a promising data set for building various climatologies. In this paper we present the nighttime stratospheric ozone distribution measured by GOMOS in 2003. We show monthly latitudinal distributions of the ozone number density and mixing ratio profiles, as well as the seasonal variations of profiles at several latitudes. The stratospheric profiles are compared with the Fortuin‐Kelder daytime ozone climatology. Large differences are found in polar areas and they can be shown to be correlated with large increases of NO2. In the upper stratosphere, ozone values from GOMOS are systematically larger than in the Fortuin‐Kelder climatology, which can be explained by the diurnal variation. In the middle and lower stratosphere, GOMOS finds a few percent less ozone than Fortuin‐Kelder. In the equatorial area, at heights of around 15–22 km, GOMOS finds much less ozone than Fortuin‐Kelder. For the mesosphere and lower thermosphere, there has previously been no comprehensive nighttime ozone climatology. GOMOS is one of the first new instruments able to contribute to such a climatology. We concentrate on the characterization of the ozone distribution in this region. The monthly latitudinal and seasonal distributions of ozone profiles in this altitude region are shown. The altitude of the mesospheric ozone peak and the semiannual oscillation of the number density are determined. GOMOS is also able to determine the magnitude of the ozone minimum around 80 km. The lowest seasonal mean mixing ratio values are around 0.13 ppm. The faint tertiary ozone peak at 72 km in polar regions during wintertime is observed.

Study of vertical ozone variations over Moscow and apatity by means of millimeter-wave spectroscopy

A number of features of the vertical distribution of stratospheric ozone over Moscow and Apatity were revealed by joint millimeter-wave observations of ozone emission lines at 142.2 and 101.7 GHz carried out at the P.N. Lebedev Physical Institute and the Institute of Applied Physics of the Russian Academy of Sciences in the winter of 2002/2003. The results of these observations illustrate the high efficiency of the radiophysical techniques for ozone layer monitoring from distant ground-based stations. The joint ozone observations at two points separated to a considerable distance are an important step toward the creation of the Russian network of observatories using ground-based millimeter-wave spectrometers.

Reconstruction and Simulation of Stratospheric Ozone Distributions during the 2002 Austral Winter

Abstract Satellite-based solar occultation measurements during the 2002 austral winter have been used to reconstruct global, three-dimensional ozone distributions. The reconstruction method uses correlations between potential vorticity and ozone to derive “proxy” distributions from the geographically limited occultation observations. Ozone profiles from the Halogen Occultation Experiment (HALOE), the Polar Ozone and Aerosol Measurement III (POAM III), and the Stratospheric Aerosol and Gas Experiment II and III (SAGE II and III) are incorporated into the analysis. Because this is one of the first uses of SAGE III data in a scientific analysis, preliminary validation results are shown. The reconstruction method is described, with particular emphasis on uncertainties caused by noisy and/or multivalued correlations. The evolution of the solar occultation data and proxy ozone fields throughout the winter is described, and differences with respect to previous winters are characterized. The results support the idea that dynamical forcing early in the 2002 winter influenced the morphology of the stratosphere in a significant and unusual manner, possibly setting the stage for the unprecedented major stratospheric warming in late September. The proxy is compared with ozone from mechanistic, primitive equation model simulations of passive ozone tracer fields during the time of the warming. In regions where chemistry is negligible compared to transport, the model and proxy ozone fields agree well. The agreement between, and changes in, the large-scale ozone fields in the model and proxy indicate that transport processes, particularly enhanced poleward transport and mixing, are the primary cause of ozone changes through most of the stratosphere during this unprecedented event. The analysis culminates with the calculation of globally distributed column ozone during the major warming, showing quantitatively how transport of low-latitude air to the polar region in the middle stratosphere led to the diminished ozone hole in 2002.

Impact of stratospheric dynamics and chemistry on northern hemisphere midlatitude ozone loss

The importance of dynamics for stratospheric ozone distribution in the northern hemisphere is investigated by using multiannual simulations of the coupled dynamic‐chemical general circulation model ECHAM3/CHEM. This model includes a parameterization for heterogeneous reactions on the surfaces of polar stratospheric clouds (PSCs) and on sulfate aerosols. A warm and a cold stratospheric winter are examined to estimate the range of chemical ozone loss in the model due to heterogeneous reactions on PSCs. Ozone depletion in the model mainly occurs inside the polar vortex. An additional ozone reduction due to heterogeneous reactions on PSCs is found outside the polar vortex. Secondary vortex formation and vortex contraction after an elongation lead to a transport of air masses with chemically reduced ozone values out of the vortex. Except for such events the edge of the modeled polar vortex acts as a barrier to transport. During the formation of secondary vortices no additional heterogeneous reactions occur therein. Other dynamic events, such as the elongation of the polar vortex and its displacement to lower latitudes, lead to an intense ozone depletion. A minor stratospheric warming in the model causes a total deactivation of chlorine compounds and prevents further ozone depletion. In midlatitudes, the amplitude of short‐term variations of total ozone is amplified by PSC heterogeneous chemical ozone reduction.

Direct measurement of tropospheric ozone distributions from space

The role of ozone in absorbing ultraviolet solar radiation is well known. Ozone also makes a significant contribution to the radiative balance of the upper troposphere and lower stratosphere, such that changes in the distribution of ozone in these atmospheric regions will affect the radiative forcing of climate1,2. Furthermore, tropospheric ozone is the source of the hydroxyl radical which controls the abundance and distribution of many atmospheric constituents, including greenhouse gases such as methane and hydrochlorofluorocarbons. Tropospheric ozone is produced photochemically in situ and is also transported down from the stratosphere, but the relative importance of these two sources to its global budget is poorly understood. High-quality tropospheric and lower-stratospheric ozone profile measurements are available from sondes and lidar techniques, but their geographical sampling is very limited. Complementary satellite measurements of the global ozone distribution in this height region are therefore required to quantify ozone's tropospheric budget and its participation in climate-forcing and tropospheric chemistry. Here we present direct measurements of tropospheric ozone concentrations from space, made by the European Space Agency's Global Ozone Monitoring Experiment. These results demonstrate the potential of satellite measurements to provide self-consistent tropospheric and stratospheric ozone distributions on a global scale.

Effects on stratospheric ozone and temperature during the Maunder Minimum

The period of low solar activity between 1645 and 1715, known as the Maunder Minimum, corresponds to a period in which the ultraviolet spectral irradiance was significantly smaller than found in the current atmosphere [Lean et al., 1995a]. In this study, we use our two‐dimensional chemical‐radiative‐transport model of the global atmosphere to examine the effect of this reduced solar flux on the distribution of stratospheric ozone and temperature relative to that normally expected for the pre‐industrial atmosphere. A decrease in total global ozone of about 3% was determined for the Maunder Minimum period. Lean et al. [1995b] have examined the implications of the direct solar irradiance effects on climate during that period. The changes in stratospheric ozone may further have influenced the radiative forcing on climate during that period. In addition, such events are lilely to happen again with resulting decreases in ozone.

Scale invariance in meridional distribution of stratospheric ozone

Analysis of SBUV measurements of stratospheric ozone in 1983–1984 shows that ensemble meridional distributions of the ozone mixing ratios exhibit scale invariance (or scaling) over the scale range 208–6660 km, or at least 208–3330 km, in 100-50 mb and 15-7 mb layers, such that meridional variations at small scales are (on average) related to larger ones by the same scale law. The scaling laws are determined from meridional structure functions of ozone mixing ratios. The scaling exponent depends on height and season and is different for the Northern and Southern Hemispheres.

Rocket-borne optical ozone dropsonde (roood) for calibrating the satellite observation of stratospheric ozone

An optical dropsonde using a MT135 meteorological rocket has been developed to measure the altitude distribution of stratospheric ozone. It is based on the solar ultraviolet absorption technique that is self-calibrating, enabling us to retrieve ozone density profiles in the altitude range of 25–50 km with an average error of 3%. The technique is useful for calibrating the satellite measurement of ozone at 35–50 km altitudes where the long-term change of ozone is occuring due to solar and anthropogenic forcings. A test flight was successfully made at Uchinoura (31°N) in August 1990 and two flights each in February and early September 1991. The stratospheric ozone profile is found to be less variable from day to day in late summer at Uchinoura, suggesting a capability for the ozone trend detection in middle and upper stratosphere. A comparison was made with the SAGE II ozone measurement to exhibit a general agreement within ±10% in the altitude range of 23–47 km.

Some features of the vertical ozone distribution from millimeter wave measurements at Pushchino and Onsala observatories

A number of features of the stratospheric ozone distribution were revealed by joint millimeterwave observations of ozone emission lines at 142,175 and 110,836 GHz carried out during the winter periods of 1988–1989 and 1989–1990 at the Radioastronomical Observatory of the P.N. Lebedev Physical Institute of the Russian Academy of Sciences and at the Onsala Space Observatory of Chalmers University of Technology, Sweden. It is shown that vertical ozone variations observed at the two observatories were connected with large scale dynamical processes that occurred in the stratosphere. When the stratosphere was relatively undisturbed the ozone profiles obtained at both observatories were close to the ozone reference model given by Keating and Pitts. There were periods during a stratospheric warming when the ozone content measured at the two observatories in the 25–40 km altitude range was higher by a factor ~ 1.5 than the model values. Dynamical processes in the stratosphere also gave rise to rapid (4 h duration) and large deviations from the model ozone profile. An ozone layer depletion was observed in the 27–55 km altitude range. The observed ozone variations illustrate the sensitivity of the ozone distribution to stratospheric disturbances including stratospheric warmings.

An important uncertainty in coupled chlorine–carbon dioxide studies of atmospheric ozone modification

There has been considerable interest recently in changes in the composition of the stratosphere following the suggestion by Molina and Rowland1 that certain fluorocarbons could ultimately lead to ozone destruction. This interest has increased since the discovery in 1985 of large ozone decreases over Antarctica2. It is now known that many species have the potential to modify the stratospheric ozone distribution either directly, by photochemical processes, or indirectly, through changes in atmospheric temperature by modification of the transmission of infrared radiation. Here we present calculations using a two-dimensional atmospheric model of the effect on stratospheric ozone of increases in the atmospheric abundances of CO2 and various chlorine-containing compounds. We have carried out such calculations previously3 but changes in the kinetic data used in the model have led to very significant differences in the calculated ozone modification. In particular, the lower stratosphere, a difficult region to model, now plays an even more crucial role in the vertically integrated ozone depletion. We believe that uncertainties in the thermal response of the lower stratosphere represent a significant limitation in our ability to predict future states of the middle atmosphere.

Upper stratospheric (30–50 km) lidar observations of the ozone vertical distribution

A maximum reduction of 20% of the ozone content in the altitude range 35–45 km is presently expected within the next 50 years. Early detection of trends is thus of particular importance to confirm such extrapolations. An active lidar system, which uses a powerful exciplex laser as the emitting source at 308 nm, has been operated at the Observatoire de Haute Provence to probe the upper stratospheric ozone distribution. A description of the lidar system and results of the measurements are given and compared with those obtained simultaneously by already proven techniques, such as Brewer‐Mast sondes and Umkehr spectroscopic measurements. A general agreement within the uncertainties of the various methods is found. The data are further analyzed to determine a total error budget and to extrapolate the potentiality of lidar systems, using up‐to‐date laser sources to reach a precison better than 3% in the considered altitude range.

North-south asymmetries of solar particle events in upper stratospheric ozone

Stratospheric ozone depressions, following intense solar particle events (SPE) observed by the backscattered ultraviolet (BUV) experiment on the Nimbus-4 satellite, indicate the existence of distinct asymmetries between the Northern and Southern Hemispheres. These asymmetries are observed in the magnitude of the depressions above the 5-mb level, their temporal variations, and the spatial (i.e., latitude and longitude) dependence of these variations. Possible causes of asymmetries, shown by two events on 4 August 1972 and 25 January 1971, can be attributed to: (1) tilt of the interplanetary magnetic field (IMF) with respect to the Earth's dipole magnetic field which influences the precipitation of energetic solar particles into the polar atmospheres; (2) differences in ozone chemistry caused by the large change in atmospheric temperature between summer and winter hemispheres; (3) seasonal differences of the stratosphere's dynamic states which are affected by upward propagating planetary waves in winter in contrast to the relatively undisturbed zonal flow in summer; (4) topographic asymmetry between Northern and Southern Hemispheres. These effects are shown by three-dimensional plots of the events in geographic coordinates and by color contour plots of the stratospheric ozone distributions in geomagnetic and geographic polar coordinates, respectively.

Ozone profile intercomparison based on simultaneous observations between 20 and 40 km

The vertical distribution of stratospheric ozone has been simultaneously measured by means of five different instruments carried on the same balloon payload. The launches were performed from Gap during the intercomparison campaign conducted in June 1981 in southern France. Data obtained between altitudes of 20 and 40 km are compared and discussed. Vertical profiles deduced from Electrochemical Concentration Cell sondes launched from the same location by small balloons and from short Umkehr measurements made at Mt Chiran (France) are also included in this comparison. Systematic differences of the order of 20% between ozone profiles deduced from solar u.v. absorption and in situ techniques are found.

Dayglow emissions of the O 2 Herzberg bands and the Rayleigh backscattered spectrum of the earth

Numerous fluorescent emissions from the Herzberg bands of molecular oxygen lie in the spectral region 242–300 nm. This coincides with the wavelength range used by orbiting spectrometers which observe the Rayleigh backscattered spectrum of the earth for the purpose of monitoring the vertical distribution of stratospheric ozone. Model calculations indicate that Herzberg band emissions in the dayglow could provide significant contamination of the ozone measurements if the quenching rate of O 2(A 3Σ) is sufficiently small. This is especially true near 255 nm, where the most intense fluorescent emissions relative to the Rayleigh scattered signal are located and where past satellite measurements show a persistent excess radiance above that expected for a pure ozone absorbing and molecular scattering atmosphere. However, very small quenching rates are adequate to reduce the dayglow emission to negligible levels. Available laboratory data have not definitely established the quenching on the rate of O 2(A 3Σ) as a function of vibrational level, and such information is required before the Herzberg band contributions can be evaluated with confidence.

Spatial-Frequency Response Of The Limb Infrared Monitor Of The Stratosphere (LIMS) Radiometer

The Limb Infrared Monitor of the Stratosphere (L[MS), an experiment on the NIMBUS-7 satellite, is designed to scan the earth's limb vertically and measure spectral emission profiles of trace atmospheric gases believed to be important in processes controlling the stratospheric ozone distribution. Experiment objectives are reviewed and several analyses and measurements are described which were performed to determine the adequacy of the system for satisfying these objectives. Adequate spatial-frequency response for all the spectral channels is required to provide, through inversion of the measured limb-radiance profiles, important information about the temperature, structure, and composition of the atmosphere. From the LIMS design-model data, the MTF was calculated for the optical system, the detector field mask, the electronics, and the overall system, for each channel. The signal output performance of the instrument was predicted from the system MTF data and model input radiance data for each channel. MTF measurements made on the flight sensor confirmed the analytical results. The predictions indicate that the instrument can satisfy the basic measurement objectives of the experiment.