Behavior Of Ozone Research Articles

Meteoric material and the behavior of upper stratospheric polar ozone

Analysis of October SBUV ozone profile data in the antarctic polar vortex shows that there was a decrease in ozone between 1979 and 1984 of between 15 and 30% at all levels from 30 mb to 0.7 mb. During spring of 1983 at 75° to 80°S the ozone mixing ratio at 1 mb decreases continuously from September through the summer solstice and then increases in late summer and fall, but we observe much less ozone at 1 mb in September and October than under similar conditions in the fall. This asymmetry between spring and fall ozone values may be the direct result of the sudden release of chlorine bound by meteoric material during polar night. Meteoric atoms, X, descending from the mesosphere react with the atmosphere to produce XOH, which will interact with HCl to form salts, XCl. Since these processes continue in the absence of sunlight, chlorine may accumulate during polar winter. The sudden release of this chlorine from photodissociation of these salts during spring could give rise to the loss of ozone in the upper stratosphere. At 30 mb ozone decreases substantially in mid‐September and remains at a low value until the mid‐October increase. Different mechanisms may be required to explain the ozone decreases in the upper stratosphere and in the lower stratosphere.

Interpretation of ozone temperature correlations: 2. Analysis of SBUV ozone data

In an effort to understand the behavior of ozone in the transition region, the terms in the perturbation continuity equation have been evaluated from solar backscattered ultraviolet ozone data, National Meteorological Center temperature data, and geostrophic winds derived from the temperature data at 2 mbar, winter 1978–1979. A linear parameterization is used to estimate the chemical source term. The perturbation ozone field calculated by integrating the net forcing evaluated from the data compares well with the measured perturbation ozone field. There are occasions during the winter when the sum of the dynamic terms is small due to cancellation, and the ozone and temperature perturbations are anticorrelated. The −1 correlation between the ozone and temperature perturbations does not necessarily imply that chemical forcing is dominant.

Tropospheric ozone: The role of transport

The Geophysical Fluid Dynamics Laboratory general circulation/transport model, with photochemistry in the top level (middle stratosphere) only, is used to simulate global tropospheric ozone distributions for upper and lower limits of surface removal rates. We compared these simulations with available observations and find that large‐scale atmospheric transport plays a major role in the behavior of tropospheric ozone. Furthermore, we identify potential roles for tropospheric chemistry, discover defects in the model's simulations of transport, and gain a more global picture of tropospheric ozone. The transport model's mean cross‐tropopause flux is in the range of previous estimates, and the shapes of the simulated vertical profiles of mixing ratio and percent standard deviation are in good agreement with observations. South of 40°N, the simulated and observed latitude gradients are the same, the upper and lower limit calculations bracket measured values, and the seasonal cycles are well reproduced. While the transport model simulates a wide range of tropospheric ozone climatology, there are a significant number of disagreements. The need for additional ozone destruction in the maritime boundary layer suggests a role for chemical destruction, while in the continental boundary layer, it appears that chemical production, a seasonal cycle in surface deposition, and improved boundary layer transport are all required. The two major defects in the simulated “free troposphere” are (1) excess ozone at high latitudes of the northern hemisphere (NH) and (2) spring rather than summer maxima and fall rather than winter minima at NH mid‐ and high latitudes. While defect 1 has a number of possible causes, deficiencies in model transport play a major role. Although similar transport defects have not been ruled out for defect 2, tropospheric chemistry appears to be needed. Separate calculations of the net chemical production and loss demonstrate that this is a complex problem. The most likely solution involves the transport control of NOx which controls the ozone chemistry.

The temporal behavior of upper stratospheric ozone at low latitudes: Evidence from Nimbus 4 BUV data for short‐term responses to solar ultraviolet variability

Ozone mixing ratios at pressure levels near 2 mbar, derived from Nimbus 4 backscattered ultraviolet (BUV) profile data and averaged within 13 latitude zones between 65°N and 65°S, are studied for the period November 1970 to April 1972. In agreement with previous analyses the largest temporal variations are negatively correlated with changes in zonally averaged equivalent temperature measured simultaneously with the Nimbus 4 selective chopper radiometer. After approximately removing this component using a first‐order photochemical model, residual mixing ratios for latitudes ≲30° contain short‐term variations (periods ≲35 days; rms amplitude ∼1%) that are positively correlated with variations in the solar 10.7‐cm flux and in the 185–190 nm solar ultraviolet flux model of Lean et al. (1982). The correlation coefficients (R = 0.2–0.5; p> 0.95) are larger for each latitude zone when computed versus the ultraviolet flux model than when computed versus the 10.7‐cm flux, suggesting that photochemical responses of upper stratospheric ozone to solar ultraviolet variability at wavelengths near 200 nm are primarily responsible. At latitudes ≳40°, larger‐amplitude wintertime ozone fluctuations associated with planetary‐scale pressure waves become dominant and reduce the computed correlation coefficients to statistically insignificant levels. Linear regression analyses are performed to obtain estimates for the average percent change of ozone at low latitudes and on the considered time scale for given changes in 10.7‐cm flux and in the UV flux model.

Kinetic behavior of ozone in aqueous solutions of substituted phenols

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTKinetic behavior of ozone in aqueous solutions of substituted phenolsMirat D. Gurol and Seyyedhassan NekouinainiCite this: Ind. Eng. Chem. Fundamen. 1984, 23, 1, 54–60Publication Date (Print):February 1, 1984Publication History Published online1 May 2002Published inissue 1 February 1984https://doi.org/10.1021/i100013a011RIGHTS & PERMISSIONSArticle Views550Altmetric-Citations97LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (878 KB) Get e-Alerts

Transport and the seasonal variation of ozone

The transport mechanisms responsible for the seasonal behavior of total ozone are deduced from the comparison of model results to stratospheric data. The seasonal transport is dominated by a combination of the diabatic circulation and transient planetary wave activity acting on a diffusively and photochemically determined background state. The seasonal variation is not correctly modeled as a diffusive process.

A Statistical Analysis of Total Ozone Data from the Nimbus-4 BUV Satellite Experiment

Abstract Total ozone data from the Nimbus-4 BUV satellite experiment for the period April 1970–April 1977 is analyzed to: 1) provide a better appreciation and-understanding of the global distribution and behavior of total ozone, with emphasis on any possible trend in ozone, 2) compare with ground-based Dobson total-ozone data for possible instrument calibration and drift errors. and 3) examine the extent to which total ozone data at a particular network of 36 Dobson ground-station locations is representative of global ozone behavior for the detection of trend. Linear regression models containing annual, semi-annual, biennial and linear trend components are estimated for monthly time series of zonal averages of satellite data and the nature of the variation in these components with latitude is presented. An analysis of daily BUV satellite-Dobson ground ozone data is performed which shows a definite downward drift in the satellite data estimated at ∼−1.5 m atm-cm per year relative to a Dobson network of 36 ...

Photolytic effects of solar radiation at stratospheric levels during sunrise and sunset

The different terms of the photochemical mechanisms involved in the ozone steady state at upper stratospheric levels have been computed and followed as a function of time during twilight. The photodissociation coefficients have been calculated as functions of [Formula: see text] and [Formula: see text] which represent the column densities of oxygen and ozone above a given level. Chlorine chemistry has not been considered. It is shown that, at 45 km, the ozone behavior during twilight is governed mainly by photochemical processes. Under "usual conditions" defined by a night-time NO2 density of 6 × 108 cm−3, the ozone decreases by approximately 1%. Under "high NO2 conditions" defined by a night-time NO2 density of 3 × 1010 cm−3, the ozone decreases by several percent. Due to its action upon the kinetic rate constants, an increase of the atmospheric temperature emphasizes this decrease.The calculated ozone variations are compared with measurements by different experimenters using various methods. The increase during morning twilight measured by one of them cannot be reproduced with the model developed hereafter. The decrease measured by the others shortly before sunrise is more important than is calculated in the present work.

Surface ozone measurements in clean air

Surface ozone measurements at the four baseline U.S. geophysical monitoring for climatic change observatories provide a glimpse of tropospheric ozone behavior at locations generally isolated from local anthropogenic contamination. Variations on time scales from hours to years are considered. Observations in tropical and polar regions suggest weak coupling between tropospheric and stratospheric ozone in these regions. At subtropical and mid‐latitude stations, on the other hand, there appears to be stronger coupling between tropospheric and stratospheric ozone. A small diurnal variation in surface ozone at Samoa may indicate photochemical influence on the ozone budget there. Some of the year‐to‐year differences in surface ozone at the four stations indicate possible global influences on the tropospheric ozone budget. No significant long‐term trends are apparent in the data, however.

The behavior of ozone near the stratopause from two years of BUV observations

Two years of Nimbus 4 backscattered ultraviolet data have been recalibrated and reprocessed. A Laplace transform inversion was applied to radiances at 2876 Å and below for 560,000 individual scans for the period April 1970–May 1972. The behavior of ozone near 50 km as a function of time, latitude, and longitude is presented. The high‐latitude 1‐mbar ozone mixing ratio is maximum at the winter solstice, about 10μg/g and is minimum at the summer solstice, about 4μg/g. Below 30° latitude the ozone is fairly constant at 4μg/g. Ozone variability is large in winter and spring and small in summer and fall.

The ozone layer-uncertainties in reaction rates

The concern about possible modifications to the ozone layer due to man's activities has prompted a number of numerical model predictions of the behaviour of atmospheric ozone. All models contain approximations, and it is importan to consider the model predictions in the light of these approximations. Apart from the purely numerical approximations, uncertainties in the treatment of atmospheric chemistry, radiation and dynamics can be identifie. See for instance Mahlmann (1975) and Harwood and Pyle (1979). The impact of recent evaluations of reactions involving HO2 was discussed by Crutzen and Howard (1978) and Whitten et al. (1978). In this note we will discuss briefly the importance to calculations of the ozone layer of the rate constants of the reactions: DOI: 10.1111/j.2153-3490.1980.tb00957.x

The ozone layer—uncertainties in reaction rates

The concern about possible modifications to the ozone layer due to man's activities has prompted a number of numerical model predictions of the behaviour of atmospheric ozone. All models contain approximations, and it is importan to consider the model predictions in the light of these approximations. Apart from the purely numerical approximations, uncertainties in the treatment of atmospheric chemistry, radiation and dynamics can be identifie. See for instance Mahlmann (1975) and Harwood and Pyle (1979). The impact of recent evaluations of reactions involving HO2 was discussed by Crutzen and Howard (1978) and Whitten et al. (1978). In this note we will discuss briefly the importance to calculations of the ozone layer of the rate constants of the reactions: DOI: 10.1111/j.2153-3490.1980.tb00957.x

A catalog of perturbing influences on stratospheric ozone, 1955–1975

There exist worldwide data on the total burden of atmospheric ozone since about 1955, and for comparison of these data with calculations using two‐dimensional radiative/chemical/dynamics computer codes, a list is needed and is here presented of all major time‐varying perturbations that have been suggested over the time frame 1955–1975. Detailed consideration is given to the following: variations in solar UV radiation with sunspot cycle, atmospheric nuclear explosions, halocarbons, major volcanic eruptions, galactic cosmic rays, and solar proton events. For material injected directly into the stratosphere, the time‐, altitude‐, and latitude‐dependent source strengths are listed, while for ground‐based sources the time‐ and latitude‐dependent atmospheric emission rates are given. Some other factors that may affect the long‐term behavior of stratospheric ozone but that cannot yet be modeled quantitatively are also listed.

The Behavior of Tropical Ozone During the Stratospheric Warming of March–April 1976

The backscatter ultraviolet spectrometer on the Atmosphere Explorer-E satellite obtained ozone data for the upper stratosphere and lower mesosphere from an equatorial orbit near the time of the March–April 1976 stratospheric warming. A simple inversion technique allows the extraction of information on the absolute ozone (O3) abundance and its longitudinal variation from the measured radiances. Between altitudes of 35 and 60 km tropical O3 in constant pressure layers exhibits increased spatial variations on length scales of 20° to 30° in longitude after the onset of the polar warming, indicating enhanced wave activity. One week after the polar vortex breakdown upper stratospheric O3 begins a relaxation toward the unperturbed state, while that in the lower mesosphere continues to show maximum variations near ±10% of the longitudinally averaged value. Although the degree of horizontal structure increases during the warming, the absolute O3 amounts averaged over longitude between 35 and 60 km in altitude remain nearly constant in time. The observed behavior is consistent with that expected from enhanced vertical transport of O3 in the tropics with accompanying adiabatic temperature changes which alter the chemical loss rate.

Destruction at the ground and the diurnal cycle of concentration of ozone and other gases

AbstractSeveral gaseous pollutants show marked diurnal variations, with daily maxima and nightly minima of concentration. The nocturnal decrease is held to be due to deposition at the ground, with isolation of the lowest layers of the atmosphere from the air above by the nocturnal inversion. In the morning, deep mixing is re‐established and brings material down to the surface from higher layers. Ozone exhibits this behaviour clearly and is convenient to study as an example, but it has been suggested by some authors that changes in the rates of gas‐phase reactions that produce and destroy ozone are responsible for the daily cycle of concentration. We have studied the destruction of ozone at the surface and conclude that this process can probably explain the nocturnal decline of concentration near the ground.Deposition rates for ozone were deduced from profiles of concentration, windspeed and temperature measured over grassland in southern England. The mean deposition velocity was 0.58cms−1 by day and 0.29cms−1 by night. The aerodynamic and surface components of resistance both increased at night, but the behaviour of the surface resistance was not consistent with stomatal control.Observations of the nocturnal decrease of ozone concentration at the same site are reported. A computer simulation of the behaviour of ozone, with a description of the nocturnal boundary layer due to Wyngaard, duplicated the major features observed, and a procedure for predicting the height of the mixed layer and the rate of decline of ozone concentration at the ground gave good agreement with observations on many occasions.The nocturnal behaviour has important consequences for the measurement of mean concentrations in the atmosphere, and for long‐range transport. Observation of the daily cycle of concentration may indicate the likely importance of the surface sink for many gases.

The effect of increased carbon dioxide concentrations on stratospheric ozone

During the past several years, much attention has been focused on the destruction of ozone by anthropogenic pollutants such as the nitrogen oxides and chlorofluoromethane. Little or no attention has been given to the influence on ozone of an increased carbon dioxide concentration for which a measurable growth has been observed. Increased carbon dioxide can indirectly affect ozone by perturbing atmospheric temperatures, which will alter ozone production, whose rate displays a fairly strong temperature dependence. This paper presents one‐dimensional model results for the steady state ozone behavior when the CO2 concentration is twice its ambient level which account for coupling between chemistry and temperature. When the CO2 level doubled, the total ozone burden increased in relation to the ambient burden by 1.2–2.5%, depending on the vertical diffusion coefficient used. Above 30 km, ozone concentrations were larger than the ambient values, a maximum increase of 16% being reached at 43 km. In this region the relative variations were insensitive to the choice of diffusion coefficient. Below 30 km, ozone concentrations were smaller than the unperturbed values and were sensitive to the vertical diffusion profile in this region (10–30 km). Ozone decreases in the lower stratosphere because of a reduction in ozone‐producing solar radiation, which results in smaller downward ozone fluxes from the region at 25–30 km relative to the flux values for the ambient atmosphere. These offsetting changes occurring in the upper and lower stratosphere act to minimize the variation in total ozone.

A simple calculation of ozone depletion by chlorofluoromethanes using a two-dimensional model

THE possible perturbation of the total amount of ozone in the atmosphere due to man's activities has been the subject of much recent research. The vast majority of perturbation calculations have been performed using one-dimensional models in which variations in the vertical alone are considered. I describe here some simple calculations of the effects of chlorofluoromethanes on the ozone layer using a two-dimensional (latitude and height), time-dependent numerical model in which the mean circulation is computed at each time step. In our two-dimensional treatment the eddy transports of heat and matter are calculated using two-dimensional eddy diffusion coefficients, based on atmospheric statistics, and the eddy momentum fluxes are average monthly values for 1973 deduced from the Nimbus V Selective Chopper Radiometer measurements. The approach has proved successful in modelling many features of the unperturbed atmosphere and, in particular, of the behaviour of ozone in the stratosphere1.

High-level warmings and total ozone over a tropical region

The rocketsonde data obtained from the launchings made at Thumba (8°32′15″N, 76°51′48″E) during the winter period 1970–71, as already reported, have indicated that warmings of noticeable magnitude occurred at high levels (upper stratosphere and mesosphere) over this tropical station during the period mentioned. The mean monthly radiosonde temperatures of 50, 100 and 300 mb levels at Thumba (Trivandrum) and Delhi (28°35′N, 77°12′E) during the same period have also pointed out certain anomalies consistent with the warmings referred to above at Thumba. The radiosonde temperatures of the two stations, Thumba (Trivandrum) and Delhi, have now been examined, along with the values of total ozone, for the ten winter periods commencing from 1961–1962. The analysis has pointed out the possibility of high-level warmings also having occurred in the past over the Indian region during the winters of 1963–1964 and 1967–1968, which are also the periods when prominent warmings are definitely known to have occurred at higher latitudes. The behaviour of total ozone has been found to be different in the different years of the warmings. The features noticed have been presented and discussed.

Aerometric factors affecting the evolution of the Pasadena aerosol

This paper describes briefly the meteorological background and the aerometric measurements conducted during the 1969 Pasadena smog experiment. Observations of the winds, the air temperature, humidity, and incoming solar radiation at the experiment site, with support of U. S. Weather Bureau data, indicated that the weather during the study was generally quite regular and was consistent with the Southern California climatology. The winds were light and mainly from the southwest sector during the day, indicating that the polluted air observed in Pasadena would be a complicated mixture of material produced locally and entering the area from distant sources. The observations of such gases as CO, NO, NO 2, oxidant (mostly ozone), hydrocarbons, and SO 2 bore out this conjecture in that the hourly concentration patterns were somewhat variable from day to day. The diurnal averages of such data were more revealing in trends, however, showing typical changes of gases linked with the smog reactions observed during other similar studies. Of particular interest was the simultaneous peaking of SO 2 with ozone at midday. Accompanying the midday maximum of ozone was a maximum in the scattering coefficient b scat as observed by an integrating nephelometer. The frequently observed visibility restrictions during periods of photochemical smog formation have been associated with changes occurring principally in the 0.1− to 1.0-μm diameter range of particles. Comparison between the diurnal average variations of the total number concentration of aerosols ( N) the average surface area ( S) and the volume fraction (φ) showed different behavior. While ( N) increased throughout the daylight hours until late afternoon, (φ) displayed a peak at midday in a manner similar to the behavior of ozone. ( S) showed a broad maximum through the daylight hours. Since ( S) and (φ) are linked mainly with the fraction of suspended particles greater than 0.1-μm diameter, this portion of the particle size spectrum may have evolved by photochemically induced interaction with the suspending gases. Two possible mechanisms for the growth of the large particle fraction are inferred. The first involves heterogeneous nucleation of condensable vapors, and the second postulates a combination of particle coagulation and photochemical reactions of low molecular-weight hydrocarbons, nitrogen compounds, and sulfur dioxide on the surface of small particles.

Ozone behaviour associated with the middle stratospheric circulation during the southern spring of 1967

AbstractLarge changes in the temperature and ozone content of the stratosphere at Aspendale (38 S, 145 E), Hobart (43 S, 148 E) and Macquarie Island (54 S, 160 E) are associated with the passage of planetary waves in the Antarctic polar vortex. Application of the conservation equation to an elliptical model of the polar vortex, using both ozone and potential temperature as tracers, leads to order of magnitude estimates of the vertical and horizontal motions and transports involved. Estimated vertical motions are of the order of 1 cm s−1. At the 30‐mb level there is significant horizontal advection of ozone into the vortex in the vicinity of the cold troughs and out of the vortex near the ridges, but horizontal advection of heat appears to be negligible.