nformation about the stability of the atmosphere is a very important factor in now casting and short term forecasting. Atmospheric Stability is usually estimated based on Radiosonde instability indices data. But due to a very low number of meteorological stations having Radiosonde and the cost of lunching them using satellite images could be a proper alternative. In this study، the accuracy of survey data obtained from Moderate Resolution Imaging Spectroradiometer (MODIS) atmospheric profile products in order to predict atmospheric instability versus Radiosonde observed values has been investigated. Three extracted MODIS instability indices TT، L and K are compared with Tabriz station Radiosonde data at 00 (UTC). The Tabriz weather، airport station has been selected due to its high frequency of thunderstorms (over 35 thunderstorm days per year) and the existence of an upper air station in the spring and summer of 2007as a case study. It has been observed that the TT، L and K instability indices obtained from Radiosonde and MODIS show good correlation with respectively the correlation coefficient of 0. 46، 0. 55 and 0. 60 in spring and 0. 64، 0. 65 and 0. 67 in summer، and therefore the spatial interpolation of these indices in areas where there is no Radiosonde information is possible. Also by the investigation of the average absolute error، the K and TT indices showed less error in summer than spring while the L index showed less error in spring than in the summer. It was also observed that the instability indices values obtained from MODIS were underestimated compared with Radiosonde and it''s much more significant in the spring.

Lack of attention to environmental, economic, structural and service sustainability destroys agricultural production. Therefore, for stability in the agricultural sector, it is necessary to pay attention to sustainable production criteria.In this paper, the composite indices of environmental, economic, and service-structural productivity sustainability of barley and maize in the provinces of Iran during 2001-2019 were calculated using Integration AHP and TOPSIS approaches, and then the indices of each province were classified separately with ISDM method. In the AHP prioritization results have more preference environmental, economic, and service-structural criteria, respectively. In most provinces, during the time period Average sustainability barley and maize are more sustainable in economic, environmental and service-structural criteria respectively. The results periodic averages and ISDM classification of barley and grain corn criteria in during the time period, indicated that the downward trend in barley and maize sustainability criteria and rising trend for economic criteria in the some provinces due to the improvement of labor productivity. Also in most provinces the sustainability of environmental, economic and service-structural criteria was roughly divided into three periods: 2001-2008, 2009-2014, and 2015-2019. In most of the provinces, the results ISDM classification three sustainability criteria were mostly in the moderate class and in the moderate unsustainable subclass is more than the moderate sustainable subclass. The most effective factor in environmental sustainability is water resources, in economic sustainability is income and profit and in service-structural sustainability is packaging and transportation. It is suggested that environmental sustainability with management in the consumption of water resources and inputs and increasing water productivity; Economic stability by organizing product prices and production costs; And service-structural sustainability should be improved by organizing packaging and transportation, and agricultural subsidies should be applied considering sustainability.

Convective systems are meso-scale atmospheric phenomena which their intensity of activity is determined by atmospheric static stability indices (convective indices). The effect of large-scale teleconnections on the increase or decrease in the potential for occurrence of convective systems in the atmosphere is of particular importance. Therefore, study of the climatological distribution of atmospheric stability indices along with teleconnections can be important in predicting convective systems. Given the lack of a comprehensive study of the relationship between the two phenomena, the purpose of this study is to investigate the climatological distribution of some atmospheric stability indices and their relationships with some teleconnections over the West Asia.In this study, first using JRA55 reanalysis data with a horizontal resolution of 1.25×1.25 degree during the period 1958 to 2018, four atmospheric stability indices including Convective Available Potential Energy (CAPE), K Index (KI), Lifted Index (LI) and Total Totals Index (TTI) were calculated. Then, in the first part of this study, the average seasonal distribution of these indices on the West Asian region in the range of 0 to 60 degrees north and 10 to 90 degrees east are presented. Next, in the second part of this study, the relationship between atmospheric stability indices and teleconnections is examined. For this purpose, by determining the critical phases of the four teleconnections, including the North Atlantic Oscillation (NAO), East Atlantic/West Russia (EA/WR), Indian Ocean Dipole (IOD) and Madden–Julian Oscillation (MJO), the difference in distribution of the average atmospheric stability indices for the positive and negative critical months of these teleconnections is investigated in spring season during the study period on the West Asia.The results of the first part of this study showed that the seasonal distribution of atmospheric stability indices on the study area is affected by the seasonal cycles of temperature and humidity associated with the ITCZ displacement. The results also showed that the maximum values of the stability indices occur in summer over lowland areas and the minimum ones in winter and highlands. The results of the second part showed that generally the area in which the atmospheric stability indices have significant values over the most parts of the study area decreases (increases) during the positive (negative) phases of the two northern indices of NAO and EA/WR, but increases (decreases) during the positive (negative) phases of the two southern indices IOD and MJO. The highest increase of CAPE index during the negative phase of NAO (EAWR) compared to its positive phase on the Oman Sea (East India) exceeds +250 (+450) J/kg and also during the positive phase of IOD (MJO) compared to its negative phase on Western India (Oman Sea) exceeds +450 (+600) J/kg.

One of the problems raised in the steel industry is various pollutants produced by chemical interactions during steel production. Toxic emission modeling used to analyze the effect of pollutants on the environment. In this study mathematical modeling of air pollutants and carbon dioxide emission modeling was performed using software. Mass emission, specifications of exhausted smoke and chimney, meteorological data of topographic situation have been used as the main input of software. According to results the pollutants disperse more as the atmospheric stability decreases; as the wind speed is low the emission zone increases in different months of the year and in the same climate conditions due to lower mixing. Also the results showed that temperature and humidity has less effect than wind in pollutant dispersion. The highest pollutants were related to November and the lowest pollutants were related to December, January and June respectively.

Forest fire is considered as a natural disaster and a major potential threat in many parts of the world. It also has a huge impact on the form and compounds of different species and the spatial pattern of plant coverage. Fires in forests and pastures are one of the world's most important issues, not only environmentally, but also from an economic and social aspect. Forest fires usually result in the destruction of the forest or its renewal which is of different importance in different regions regarding its destruction and the amount of damages it brings about, because its severity depends on the climate of the region in which it occurs. Forest fire is a primary process which also affects botanicals and their spatial structure. The emitted smoke from forest fires is amongst the most worrying consequences of this phenomenon. Fires have a large impact on the quality of air and human health, because they release large amounts of compounds such as carbon dioxide (CO2), carbon monoxide (CO), methane (CH4), nitrous oxide (NOX), ammonia ( NH3), particulate matter (PM), non-methane hydrocarbons (NMHC) and other chemicals in the atmosphere. On the other hand, as a result of forest fires, the soil loses a large degree of its organic materials, the risk of soil drifting increases and it also has significant negative impacts on the regeneration of previous species and the environmental conditions. Many physical, chemical, mineralogical and biological features of the soil are changed as a result of the forest fires. Due to the fact that Iran is at a critical condition with regard to its forest ecosystem and this ecosystem has experienced huge fires on an annual basis, the necessary measures should be taken to identify the causes of forest fires and prevent them if possible.
Study area: The city of Dezful is located at the plain areas of Khuzestan province, Iran, with an area of 7844 km. This city has expanded at the geographical longitude of 48 ° and 24 minutes east and latitude of 32 ° and 22 minutes north and its height is 140 meters above the sea level. Like most cities in Khuzestan, Dezful has a warm and humid climate with hot summers and Mediterranean winters. The annual average precipitation in Dezful is 250 mm and its average temperature is 3° C in winter and 49 ° C in summer.
Material and In this study, two sets of data were used to analyze the fire at Dezful’s forests. First, the statistics regarding the fires were received from the department of forest and rangelands and in order to synoptically analyze this phenomenon, the data from the upper levels of atmosphere were taken into consideration. Based on a report submitted on 12.05.2012 and 08.01.2012 (23rd Ordibehesht and 11th Mordad 1391 in the Iranian calendar), two of the fiercest forest fires of 2012 in Iran have occurred in Dez and Dezful national parks which have resulted in 700 and 270 million Tomans damage to the forests and natural rangelands of Khuzestan Province, respectively. In order to analyze this damaging risk from an atmospheric point of view, the induced data of the components of sea level pressure, geopotential height, orbital and meridional wind at 2 meters above the ground and the upper levels of atmosphere, the temperature of different levels of the atmosphere and 2 meters above the ground and the relative humidity which were taken from the website of the National Center for Environmental Prediction (NCEP) were used. The maps which have been drawn and analyzed for the atmospheric analysis of forest fires in Dezful include the maps of sea level pressure, geopotential height, the thickness of the atmosphere, wind direction, atmospheric temperature, vorticity, thermal wind and relative humidity. The maps were analyzed at the following levels: temperature maps at the levels of 850, 925, 1000 HP and maps at 2 meters above the ground, maps of geopotential heights and wind currents at different levels (500, 600, 700 and 850 HP), vorticity maps at the levels of 1000, 925, 850, 700, 600 and 500 HP, thermal wind map at the levels of 1000, 925, 850 HP, wind and thermal wind at 2 meters above the ground, and relative humidity map at the levels of 1000, 925, 850, 700, 600 and 500 HP. All the maps were developed at the latitude of 15-70 and longitude of 10-75 and the time for drawing the maps was selected to be 12 Zulu time which is equivalent to 3:30 P.M. local time because of the higher visibility of the phenomenon under study.
Discussion and Findings: The analysis of atmospheric maps indicated that at the time of occurrence of fires in thermal forests, the blocking phenomenon associated with a stack on the study area on the 12th of May and very high contours on the 1st of August were observed.The thickness of the atmosphere which is a sign of the establishment of a hot system, hot thermal wind above the region with the dominance of thermal conditions and temperature of above 40 ° C on the 12th of May and the temperature above 48 ° C on the 1st of August are amongst the other dominant atmospheric patterns these days. Atmosphere stability and negative vorticity flow which has been followed by the subsidence of the warm air flow of southern latitudes from upper levels to the ground level together with very low relative humidity (10%), which has imposed a dry atmosphere on the climate of Dezful, have prepared the necessary conditions for the occurrence of fire at the forests of Dezful.
Based on what has been stated so far, the establishment of thermal units at ground level, occurrence of blocking at the upper levels of the atmosphere and the deployment of high contours and stacks on the studied area, thickness of the atmosphere and hot thermal wind above the region with the dominance of thermal conditions and a high temperature alongside atmosphere stability and negative vorticity flow which has resulted in the subsidence of the warm air flow of southern latitudes from upper levels to the ground level together with very low relative humidity (10%) which has imposed a dry atmosphere on the climate of Dezful, have provided the necessary conditions for the occurrence of fire at the forests of Dezful. Since no study has to date investigated the thermodynamic causes of fire at the forests of the southwest of Iran and researchers have just examined the causes of this phenomenon in the northern forests of Iran, the results obtained from previous studies have similarities and conflicts with the findings of the current study. Regarding the fires which occur at the northern forests of Iran, Foehn wind is very important and flows at the high pressure ground level, while at the time of fire in the forests of Dezful, this type of wind was very important at the low pressure ground with a high pressure of central core. However, the commonality of both studies is high temperature,the relative humidity of less than 20%, the position in height, and the stack at the upper levels of the atmosphere which is observed in both the environments. In this study, some parameters have been investigated which have not been considered at all in other related studies.

A Forest fire is one of the hazardous that associated with atmospheric conditions. By studying atmospheric conditions during the fire event can realized this connection. The aim of this study is to analyze synoptic-dynamic natural hazards West Gilan forest fire on July 21, 2016 with a view to the Environmental circulation. For this purpose, the data of the upper atmosphere, sea level pressure, geopotential, vertical velocity atmosphere, wind zonal and meridional atmospheric levels of 2 meters above the ground, atmospheric levels of temperature and Maximum 2 meters surface of Earth and high radiation flux of Above the atmosphere and land surface with using GRADS software drew maps and analyzed. Atmospheric maps analysis results indicate that the establishment of a secondary low pressure center on the western side of the Persian Gulf and its expansion to the northwest of the country And in the middle of subtropical high altitude to 500 hp power package with the geo potential 5960 m Under his thick hot air subsidence for adiabatic heat combined with low pressure at ground level is of the Persian Gulf. Atmosphere's vertical velocity and vorticity maps based on high-altitude subtropical climate of the western half of the country on negative values indicates that confirmed the stability of Atmosphere and fall to the ground is warm from the upper levels. Advection maps analysis at the level of 1000 to 500 hPa temperature showed that the source of heat entering the western half of the country Advection of warm, dry air from the land of Saudi Arabia, North Africa, Iraq and the northern half of the Persian Gulf's warm waters That makes it the hottest day of the summer event and massive fires in large areas of forests have been Gilan West.

In big cities, air pollution has become a great environmental issue nowadays. In city of Tehran, 90% of air pollutants are generated from traffic, among which carbon monoxide (CO) is the most important one because it constitutes more than 75% by weight of total air pollutants. This study aims to predict daily CO concentration of the urban area of Tehran using a hybrid forward selection- ANFIS (adaptive neuro-fuzzy inference system) model based on atmospheric stability analysis. Atmospheric stability is the most important parameter affecting dilution of air pollutants. It plays a central role in the investigation of parameters that affect ambient pollutant concentrations. Therefore, it can be considered as an input parameter for developing air pollution prediction models. Although different methods are used for stability determination with varying degrees of complexity, most of them incorporate considerations of both mechanical and buoyant turbulence. In this study two aspects for atmospheric stability analysis are considered and thus, two models are developed. ANFIS1: frictional wind velocity and temperature gradient are used for representing mechanical and buoyant turbulence, respectively. For predicting CO concentration at a certain time step (CO (t)), total candidates for inputs are: CO (t-1), u10(t), u10(t-1), rad(t), rad(t-1). ANFIS2: wind velocity and solar radiation are considered as the indicators of mechanical and buoyant turbulence, respectively. For predicting CO concentration at a certain time step (CO(t)), there are 9 candidates for the inputs: CO (t-1), u10(t), u10(t-1), u24(t), u24(t-1), temp(t), temp (t-1), dtemp(t), dtemp(t-1). Input selection is a crucial step in ANFIS implementation. This technique is not engineered to eliminate superfluous inputs. In the case of a high number of input variables, irrelevant, redundant, and noisy variables might be included in the data set, simultaneously; meaningful variables could be hidden. Moreover, high number of input variables may prevent ANFIS from finding the optimized models. Therefore, reducing input variables is recommended even though this causes some of the information to be omitted. In this research, input selection is carried out based on forward selection (FS) procedure. When the number of candidate covariates (N) is small, one can choose a prediction model by computing a reasonable criterion (e.g., RMSE, SSE, FPE or cross-validation error) for all possible subsets of the predictors. However, as N increases, the computational burden of this approach increases very quickly. This is one of the main reasons why step-by-step algorithms like forward selection are popular. In this approach, which is based on linear regression model, first step is ordering of the explanatory variables according to their correlation with the dependent variable (from the most to the least correlated variable). Then, the explanatory variable, which is best correlated with the dependent variable, is selected as the first input. All remained variables are then added one by one as the second input according to their correlation with the output and the variable which most significantly increases the correlation coefficient (R2) is selected as the second input. This step is repeated N-1 times for evaluating the effect of each variable on model output. Finally, among N obtained subsets, the subset with optimum R2 is selected as the model input subset. The optimum R2 is integral to a set of variables after which adding new variable dose not significantly increase the R2. FS is applied on the input sets of this study which reduces the inputs of the models to 5 and 4 for ANFIS1 and ANFIS2, respectively. In order to identify the effect of FS on modeling results, the complete input sets are considered. Thus, 4 models are defined: ANFIS1, ANFIS2, FS- ANFIS1 and FS-ANFIS2. The selected inputs are used for Neuro-fuzzy modeling approach. Neuro-fuzzy modeling refers to the method of applying various learning techniques developed in the neural network literature to fuzzy modeling or Fuzzy Inference System (FIS). A specific approach in neuro-fuzzy development is ANFIS (adaptive neuro-fuzzy inference system), which has shown significant results in modeling nonlinear functions. ANFIS uses a feed forward network to optimize parameters of a given FIS to perform well on a given task. The learning algorithm for ANFIS is a hybrid algorithm, which is combination of the gradient descent and least squares methods. The used FIS here is the Sugeno first-order fuzzy model with its equivalent ANFIS architecture. Results show that the forward selection reduces not only calculation burden but also the output error. FS-ANFIS models produce more accurate results with R2 of 0.52 and 0.41 for FS-ANFIS1 and FS-ANFIS2, respectively. Moreover, although both models can satisfactorily predict trends in CO concentration level, FS-ANFIS2, which is based on temperature and wind speed gradients, is the superior model.

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.

Extreme precipitation has a significant impact on the frequency, severity, and duration of natural hazards, such as floods, droughts, and landslides. This has a significant impact on human life, the economy, natural ecosystems, and agriculture (Song et al, 2015: 34). Between 1880 and 2012, there was a 0.85 °C increase in the average global temperature, with a general increase in precipitation in the mid-latitudes of the Northern Hemisphere (IPCC, 2013: 2; Lio et al, 2017: 822). In addition, there is a possibility of a rise in extreme precipitation in the future (Klein Tank et al, 2006: 1), and so far, the reason for these changes and their relationship with the general circulation of the atmosphere have not been considered. The aim of this study is to analyze the trend of changes in extreme precipitation indices in northwestern Iran and its association with the general circulation of the atmosphere.

In order to analyze the changes in extreme precipitation events in northwestern Iran, daily precipitation data was collected from 20 synoptic stations in the region between 1986 and 2010. The region that is being studied encompasses West Azerbaijan, East Azerbaijan, Ardabil, Zanjan, and Kurdistan. In assessing limit events, high quality and reliable long-term climate data with daily (or higher) resolution is required (Clintanak et al., 2009: 9). The first step was to examine the quality control and homogeneity of data. The RClimDex software package, introduced as a standard tool by ETCCDI, was used to perform quality control and evaluate data homogeneity in this research. The Expert Team on Climate Change Detection, Monitoring and Indices (ETCCDMI) introduced 11 indexes to examine changes in precipitation level indices in northwest Iran. RClimDex software calculates these indicators with a significance level of 0.05. This process seeks to establish a standard set of indicators to examine and compare the characteristics of different regions. The software was used to calculate precipitation indices and display the trend and rate of change on a map.

The extreme precipitation indices were calculated to determine the regional trend and percentage of stations with positive and negative trends for the studied stations in northwestern Iran. Afterward, a map was created showing the spatial distribution of the slope for each of the indices. All precipitation indexes, except for the maximum growth period index (CDD), are declining according to the results. The probability of precipitation has decreased due to the more stable winter atmosphere in the region from the point of view of general atmospheric circulation. The region's spring atmosphere, similar to that of winter, shows an increase in stability, which will result in less rainfall. In summer, except for the coastal provinces of the Caspian Sea and the coasts of the Oman Sea, the rest of the country has recorded a decrease in rainfall of 1 mm per day. Most parts of the country experienced an increase in atmosphere thickness to 6 meters in autumn in the study area. Autumn in the region is typically stable and barotropic, but the study area is experiencing less rainfall. This study examines the trend of changes in extreme precipitation indices in northwestern Iran and its relation to a large-scale general circulation of the atmosphere. According to the results, 75% of stations in the region are experiencing a decrease in the maximum daily rainfall (RX1day) and 80% are experiencing a decrease in the maximum five-day rainfall (RX5day). While both the very wet (R95P) and ultra-wet (R99P) day indices are experiencing a downward trend, the R95P index is experiencing a more pronounced downward trend. All three indices R10, R20, and R25 have been declining for the past 25 years, but the R10 index has fallen more rapidly than the other two indices. Sarab station has a positive CWD trend alone, while other stations have a negative and decreasing trend of this index. In most stations throughout the region, the CDD index is increasing. In 85% of stations in the region, the PRCPTOT index is decreasing and there is a noticeable increase in rainfall. The SDII index is experiencing a decrease in 60% of the stations in northwestern Iran, while an increase is being observed in 40%. All precipitation indices, except for the CDD index, have a decreasing trend in general. Drawing and analyzing combined difference maps for geopotential height parameters of 500 hPa, relative rotation of 500 hPa, vertical velocity (omega), rainwater and precipitation rate to study the general atmospheric circulation of the region indicates an increase in altitude has led to a 500 hPa increase in climate stability in the study area (northwest of Iran). The study of omega and relative rotation shows that the region is experiencing a decrease in upward currents and positive rotation. The lack of atmospheric moisture load and rainfall in all seasons can be seen in rainfall water difference maps and rates. Precipitation indices and the general circulation model of the region's atmosphere are compared, indicating that the moisture load of the region's atmosphere has decreased, resulting in drought.