The OZONE layer, as a life protective shield on the Earth, has attracted the man’s attention from various aspects. For the same reason, different dimensions of the OZONE layer have been studied by researchers. The changeable amount of TOTAL OZONE is affected by the sun, atmospheric elements, and climatological photochemical activities. Hence, the major amount of OZONE is affected by atmospheric instability in the upper troposphere, and the atmospheric instability is united through the teleconnection patterns with climatic indices. Therefore, the TOTAL amount of OZONE is connected to the climatic indices. The aim of this research is to study of climatic indices on the TOTAL OZONE (TO) oscillations in Isfahan station.

The OZONE layer as a protective shield life on biosphere has very oscillations from view point of quantity and volume. The OZONE gases in both troposphere and stratosphere layers have been affecting on human life by two ways. The OZONE in stratospheric that its name is surface OZONE is an extremely poisonous gases and has destructive affect on lung and plant tissue. The surface OZONE has been measured in measurement pollutant stations as one of seven pollutant gases. The OZONE gas in stratospheric layer unlike the surface OZONE is very necessary for human and other organism lives. The stratospheric OZONE is measured in meteorological stations by name of TOTAL OZONE (TO). Studies show that amount of OZONE in stratospheric layer has been reduced. Variations in OZONE layer were effected of changing in solar radiation, volcano eruption cosmic dust, meteoric stones and etc. that those get name as natural parameter of OZONE changes. Effect of natural parameter concentration on stratospheric OZONE lead to fix OZONE content in long term (spanani 2004). The amount of OZONE in stratospheric layer particularly in the lower stratospheric has considerable oscillations (increase/decrease) under the affection of atmospheric activities. For example V. C. Roldugin (2000) showed that passing the wave crest in the pressure field ceases the convergence of OZONE poor air under the tropopause and divergence of OZONE rich air above the tropopause and decreases the OZONE content. The passing of a wave through simulate the opposite process and increase the OZONE content T. Narayana Rao at all (2003) opining that the climatology of OZONE clearly shows a significant seasonal cycle with the OZONE maxima changing with height. The monthly variability of OZONE as well as its seasonal maximum is found near the tropopause. Variation in tropopause height is due mainly to the passage of tropospheric weather systems and is responsible for the large monthly variability of OZONE near the tropopause. In the lower stratosphere, inter annual variations are at a maximum in winter and spring, and are the result of variations in wave driven stratospheric circulation, which peaks in winter. Regarding this matter that TOTAL OZONE have been affected from atmospheric parameter in lower stratosphere or upper troposphere, we decide to study the role of pattern circulation on OZONE variations in Isfahan.

The researches carried out in recent years show that the TOTAL column OZONE (TCO) could have significant diurnal variations caused by photochemical and synoptic factors. Using a ground-based Dobson OZONE instrument and Nimbus-7 TOTAL OZONE Mapping Spectrometer (TOMS) data, this paper discusses the relationship between the daily TOTAL column OZONE changes and the weather condition over Esfahan (32 37 N, 51 40 E) during 1997. To investigate the relationship between the daily TCO and synoptic conditions, 43 cases are discussed at which the daily OZONE deviations are statistically significant. A relatively good agreement is found between the tropopause height and the daily TCO changes .In addition, the jet stream shift is shown to be a very important factor affecting the TOTAL column OZONE in Esfahan, Iran. Weak or no relation was found between the daily TCO and other synoptic factors such as the type of fronts and daily surface pressure changes. The results can be employed qualitatively in a rough estimation of the daily TCO and the DV index forecast as well.

OZONE in the atmosphere serves as a greenhouse gas and a shield against ultraviolet radiation, making it crucial for maintaining ecosystem balance and promoting human health. Variations in its levels can adversely impact climate change and air quality. Therefore, monitoring OZONE concentrations is vital for creating effective environmental policies and strategies to mitigate these impacts. For this purpose, MERRA-2 data was used from 1980 to 2019. This study aims to understand the variations in OZONE levels across different regions and seasons and is comprised of two main parts. First, we analyzed spatiotemporal variations in OZONE in Iran’s atmosphere. We explored how OZONE levels change throughout the year and across different geographical locations. We found that the highest OZONE levels occurred during spring (May), whereas the lowest levels were observed in autumn (October). Geographically, the highest OZONE concentrations are observed in the northern and northwestern regions of Iran, while the lowest levels are found in the southern areas. These variations undergo monthly fluctuations influenced by various factors. In the cold season, OZONE concentration is primarily a function of latitude, whereas, in the warm season, the impact of altitude becomes significantly more pronounced than latitude. The annual ranges of OZONE change were 294 and 354.47. Notably, the TOTAL amount of OZONE in Iran’s atmosphere exhibited overall negative annual, seasonal, and monthly trends. This trend was particularly pronounced during the cold months, with statistical significance observed in winter (α=0.01). Spatially, the northwestern region of Iran, extending to its central side, exhibited a significant trend, whereas other areas showed a non-significant negative trend. This can contribute to a better understanding of OZONE dynamics in Iran and provide valuable insights for policymakers and researchers working on climate change mitigation. Extended Abstract 1-Introduction Environmental sustainability refers to the continuous preservation of natural resources and the reduction of environmental changes to maintain a balance between human activities and the environment, ensuring sufficient resources remain for future generations (Morelli, 2011). Among these, OZONE (O3) is a significant greenhouse gas in the atmosphere (Kiehl et al., 1999) with a concentration of 0.0012% (Kerr & McElroy, 1989), produced as a result of chemical reactions and unintended compounds in the Earth's atmosphere. After carbon dioxide (CO2: 1.82 ± 0.17 Wm-2) and methane (CH4: 0.48 ± 0.05 Wm-2), this gas ranks third in greenhouse effects with a radiative forcing of 0.2 ± 0.4 Wm-2 (Heue et al, 2016; Hartmann et al, 2013) and acts as a protective layer against ultraviolet radiation from the sun. Therefore, changes in this gas will have significant consequences for humans, plants, and animals. Existing studies have mostly focused on tropospheric OZONE in large cities such as Tehran, and there is a research gap regarding the spatial and temporal distribution of TOTAL atmospheric OZONE in Iran. This study, aiming to fill this gap, monitors regional OZONE levels at different time scales (monthly, seasonal, and annual) and examines its changes using non-parametric and Sen's slope methods to contribute to maintaining environmental sustainability. 2-Materials and Methods The study area is the country of Iran, with an area of approximately 1,648,195 square kilometers, located between latitudes 24° and 40° North and longitudes 44° and 64° East. As mentioned earlier, the purpose of this study is to investigate the spatiotemporal variations of TOTAL OZONE over Iran. In this regard, data from NASA’s Modern-Era Retrospective Analysis for Research and Applications Version-2 (MERRA-2) were used. NASA's MERRA-2 reanalysis data is the latest product from NASA's Global Modeling and Assimilation Office (Koster, et al., 2015). To investigate the temporal variations of TOTAL atmospheric OZONE over Iran based on the cells present within Iran's extent, two methods, Mann-Kendall and Sen's slope estimator, were employed. 3- Results and Discussion This study has two parts: a spatiotemporal analysis of OZONE and an analysis of its temporospatial changes. Based on the results of the first part, it was found that the average OZONE level in Dobson units is about 286.62, with the minimum average occurring in October (270.02) and the maximum in March (308.39). Geographically, the highest OZONE concentration is in the north and northwest of the country, and the lowest OZONE level is related to the southern half of Iran. More precisely, the lowest levels in these areas are observed in the southeastern borders of Iran and also in low-lying areas such as the Jazmourian depression. In general, the spatial distribution of TOTAL atmospheric OZONE over Iran has an increasing trend from south to north. These changes fluctuate monthly under the influence of various factors. In the cold season, OZONE concentration is mainly a function of latitude, while in the warm season, the effect of altitude is much greater and more pronounced than latitude. The amount of OZONE decreases at higher altitudes. Zhou and Yue-juan (2005) also point to the presence of low OZONE over the Iranian plateau during the summer season. And more importantly, the OZONE deficiency in the Iranian plateau is greater than that of the Tibetan plateau. Chevalier et al. (2007) point to the role of altitude in changes in OZONE levels. In general, at lower altitudes, local chemical and physical processes have a greater impact on OZONE levels, while at higher altitudes, large-scale atmospheric processes are more influential. The temporospatial changes of the study showed that the range of annual OZONE variation is between 294 and 354.47 Dobson. Other findings showed that in the overall amount of atmospheric OZONE over Iran, a negative trend is observed on annual, seasonal, and monthly scales. This research showed that stratospheric OZONE fluctuations have a strong relationship with sunspots, and numerous studies have confirmed this connection. Also, research shows that global OZONE changes by an average of about 2% during solar maximum and minimum periods. In addition, volcanic eruptions such as Mount Pinatubo and El-Chichon have also significantly affected the stratospheric composition and OZONE levels. The OZONE trend in the cold period (months) is generally more pronounced and statistically significant in the winter season. Spatially, the northwestern areas of the country to the central part of the country have a significant negative trend, and other areas show the same negative trend but are not statistically significant at any level. The findings of this research are consistent with the results of studies by Raispour and Asakereh (2018), which were conducted using satellite data received from the Giovanni website.   4- Conclusion This study is the first spatio-temporal analysis of TOTAL atmospheric OZONE changes over Iran using MERRA-2 database data. The results show that OZONE levels generally decrease from north to south and northwest to southeast, with the lowest values in southern areas such as Sarbaz and Baft. Also, the temporal behavior of OZONE shows annual fluctuations and its overall trend is negative, especially during the cold periods of the year. These changes are influenced by geographical and temporal factors, and appropriate management is essential to maintain environmental sustainability

Changing OZONE layer which is measured as TOTAL OZONE (TO) oscillation name, are one of the modern human concerns as one of the causes or impacts of climate change. In this research, TOTAL OZONE oscillation in relationship with ENSO phenomena have been evaluated. To this aim, monthly mean data from TOTAL OZONE Mapping Spectrometer (TOMS) in point by 1*1.25 degree of geographical distance and monthly mean southern oscillation index (SOI) as defining as El Nino and La Nina have been used. The results show that TOTAL OZONE variations have the best fit to SOI index by Regression Cubic model and the TOTAL OZONE could be estimated by this model on confidence level 99%. The relation between OZONE values estimated by the model and the SOI index is inverse, strong and confidence in level significant 99% in annual, seasonal and monthly time scale in all aresa of Iran except a small area in the North West in July. Correlation coefficients were the strongest in the Central Region, South and Southeast of the country and the poor relations in the North and North West respectively. The results show that the TOTAL OZONE in El Nino\La Nina occurrence will increase\decrease in all Iran areas. The value of (TO) increase from the south to north and the fitted line slope in El Nino is more.

This study introduces a new technique to fill and reconstruct daily observational of TOTAL OZONE records containing void data for some days based on the wavelet theory as a linear time-frequency transformation, which has been considered in various fields of science, especially in the earth and space physics and observational data processing related to the Earth and space sciences. The initial corrupted records consist of six years of daily TOTAL OZONE measured by Dobson Photo-Spectrometer Instrument of Institute of Geophysics, University of Tehran. To verify the filled gaps resulted from this technique, the outputs of the proposed method are compared with the TOTAL OZONE Mapping Spectrometer (TOMS) for the year 2005 and OZONE Monitoring Instrument (OMI) for the years 2006 – 2010 satellite data (hereafter used as TOMS/OMI data). The proposed technique consists of three steps: (1) quality control and denoising; (2) data-reconstruction based on Daubechies parent function (DB1); and (3) the combination of approximation and complementary coefficients using the Inverse Discrete Wavelet Transform (IDWT). Results show that this method was able to successfully reconstruct the missing data for gaps lasting no greater than 18 days. For gaps beyond this 18-day limit, however, this method was unable to reconstruct the voided data. As most instruments, including Dobson and Brewer Spectrometer, are working based on the optical interaction of stratospheric OZONE and sunshine, gaps in the TOTAL-OZONE for more than 18 days should happen in atmospheric systems with longevity over 18 days in which overcast clouds persist longer than the 18-day limit. The proposed method could be applied with high efficiency.

Different factors such as the TOTAL OZONE, cloudiness and aerosol particles influence the surface UV-B from solar radiation. UV-B is particularly dangerous to life on the surface of the earth. In this paper, the effects of TOTAL OZONE on UV-B radiation, obtained by the spectrophotometer Brewer (type MK IV) system and measurements of cloud cover over the Esfahan area using meteorological records for July 2003 to June 2004, have been considered. The results show that daily integrated UV-B radiation for this period varied between 0 to 6000 J/m2, its maximum occurred during June and July, and its minimum occurred during December and January. The maximum day-to-day variations of UV-B occurred in May and April. Also, the annual mean of integrated UV-B was approximately 3212 J.m-2.d-1(Joules per square meter per day).The results also show that UV radiation can reach critical levels for Esfahan, sufficient to have negative health consequences on humans, especially in June and July. It may be necessary, therefore, for the national weather bureau to issue warnings in this time of the year.The correlations between UV-B and TOTAL OZONE and cloudiness also show that substantial cloud cover (generally present between December and April) is more important in harmful levels of UV-B radiation than is TOTAL OZONE. When cloud cover is insignificant, OZONE is more effective in reducing UV-B radiation.The cloud factor (C) is found to be about 0.25 in this area. High cloud cover (e. g. (7-8) Octas) can reduce UV-B by 70%. Maximum cloudiness occurs during January and the secondary peak occurs in April (mid-spring). The minimum of cloudiness occurs in the period including July, August and September. Additionally, the results show that clear sky conditions usually have a cloud factor of less than 0.3, while the high cloud cover condition measures between 0.6 and 1.0. These values are in agreement with the values of other research results.Thick cloud cover ((7-8) Octas) can substantially reduce UV-B radiation. Usually, there are negative correlations between cloud cover or TOTAL OZONE and UV-B radiation. The best defined correlations during cloudy months and clear sky periods were extracted from the analyses and are as follows:Ln (UV-B)=-1.0294 C+7.8910Ln(UV-B)=-2.4156 Ln (O3)+22.235All correlation coefficients of linear regressions for the cloud factor versus UV-B is within the 99% confidence level, and for the TOTAL OZONE and UV-B it is within 95% confidence level. These relationships can be used to determine UV-B radiation in this area, for technical use. The relationship between the logarithm of daily integrated UV-B radiation and the logarithm of TOTAL daily OZONE for clear sky conditions shows that a (the Radiation Amplification Factor, RAF) has a value of about 2.4.

Introduction The OZONE is produced and destroyed by photochemical reactions between highly energetic ultraviolet photons and some gas species present in the stratosphere, especially the oxygen. OZONE was identified in the atmosphere by Schonbein (1867) and Chapman (1930) formulated the first set of chemical reactions in an attempt to explain the existence of an OZONE vertical structure (Madhu, 2016). OZONE formation starts when a highly energetic photon coming from the sun with wavelength shorter than 242 nm dissociates an oxygen molecule resulting in two atoms of monoatomic oxygen (Langematz, 2019). Then given the high reactivity of atomic oxygen, these atoms quickly react between each other to form OZONE. The OZONE effectively absorbs the highly energetic ultraviolet radiation. The result of this absorption is the dissociation of OZONE in molecular and atomic oxygen for wavelength shorter than 325 nm (Castillon, 2014,Douglass et al, 2014). OZONE is also destroyed through the recombination with atomic oxygen. The set of mechanisms presented above represent the Chapman Cycle. Atmospheric dynamics is known to be a major factor in the variability of stratospheric OZONE distribution over the tropics from year to year. There is considerable evidence that the atmospheric TOTAL OZONE amount is strongly influenced by the stratospheric circulation. OZONE is first formed in the tropical troposphere and then transported to the tropical stratosphere using Brewer-Dobson circulation. This circulation, systematically transports OZONE from tropics to the middle and high latitudes (Gerber, 2012). Stratospheric sudden warming (SSWs) is a violent phenomenon in the winter polar region (Kodera, 2006). In a minor warming the temperature gradient reverses over a range of altitude at or below 10hPa and zonal wind at 10hPa is weakens but does not change its direction. When a major sudden stratospheric warming’s events occur, the zonal mean temperature at 10hPa around the polar cap for latitudes north of 60°N suddenly rises and increases by the 25K over period of several days and zonal-mean zonal wind reversal at 10hPa and 60oN during the winter from November to March (Moradi, 1399). In this paper five major SSWs, one minor SSWs and one year without SSWs events were considered to study the variability of TOTAL column OZONE over the polar cap region. Materials and methods In this study we have used the daily mean data from the Modern Era Retrospective Analysis for Research and Applications version 2 (MERRA2) and National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) assimilated data. From the MERRA2 data, zonal wind and temperature were obtained at 10hPa and TOTAL column OZONE from 01 July 1991 to 30 Jun 1992 (1987-1987, 2008-2009, 2010-2011, 2012-20113, 2016-2017 and 2017-2018). The zonal mean temperature (TOTAL column OZONE) averaged around the polar cap for latitudes north of 60°N (63°N). This is a good measure of the overall temperature and TOTAL column OZONE content in the polar vortex. The average east-west (zonal) wind speed for 60°N. This is near the peak of the polar jet maximum. The study region covers 0. 0° to 357. 5° geographical longitudes and 60°N to 90°N geographical latitudes. From the NCEP/NCAR data, zonal wind and temperature daily were presented by a horizontal resolution of 2. 5° ×2. 5° at 10hPa in region study at different case studies and averaged from 0. 0 to 357. 5o geographical longitudes around the 60°N to 90°N geographical latitudes. To study the distribution of TOTAL column OZONE during the sudden stratospheric warming events, five major SSWs, one minor SSWs and one year without SSWs events were identified (Table 1). To represent the TOTAL column OZONE variations during the sudden stratospheric warming,the daily TOTAL column OZONE in this cases are analyzed. Table 1. Characteristics of sudden stratospheric warming Results and discussion The results showed that the during the five major SSWs events (one minor SSWs and one year without SSWs evens), TOTAL OZONE column over polar cap region is increases (decrease) and the anomaly of this quantity is always positive (negative) compared to the long-term average. Furthermore, in during major SSWs events there observed an increase of 29-70 DU in TOTAL OZONE column from the average value over the pole cap and if the major SSWs is strong TOTAL OZONE is found to rise by 99-104 DU. The positive anomaly TOTAL column OZONE in the polar cap is more in growth and maturation of the major SSWs and less in the period of decline. The longer the growth and maturation period and the faster of reduce of the zonal mean zonal flow, the positive anomaly TOTAL column OZONE is higher. During the period of growth and maturation of major SSWs, the polar vortex and night jet are rapidly weakened, and TOTAL column OZONE is better transferred from the equatorial stratosphere to the polar cap by the Brewer-Dobson circulation. During the major SSWs that warming of stratosphere, diabetic cooling on the Brewer-Dobson extra tropical down welling branch also weakens. This mechanism also increases the OZONE of the polar cap by reducing the rate of OZONE depletion. Conclusion In this study, the variation of polar cap TOTAL column OZONE during one minor SSWs case (1991-1992), five major SSWs cases (1987-1987, 2008-2009, 2012-20113, 2016-2017, 2017-2018) and one year without SSWs events (2010-2011) was analyzed over the polar cap region. The results showed that the during the five major SSWs events (one minor SSWs and one year without SSWs evens), TOTAL OZONE column over polar cap region is increases (decrease) and the anomaly of this quantity is always positive (negative) compared to the long-term average. During the major SSWs that warming of stratosphere, diabetic cooling on the Brewer-Dobson extra tropical down welling branch also weakens. This mechanism also increases the OZONE of the polar cap by reducing the rate of OZONE depletion.