Showing 142 results for Subject: climatology
Joan Amini, Mehri Akbari, Zahra Hejazizadeh, Ali Akbar Shamsipur,
Volume 0, Issue 0 (3-1921)
Abstract
Green spaces have a key role in moderating urban micro-climatic conditions, beautifying urban landscapes, citizens' leisure time, and also reducing noise and air pollution and absorption of Aerosols. In addition to the significant advantages of green space, water consumption and irrigation needs is one of the main limitations of green space development in Tehran that nowadays faced to critical water shortage. Calculating water footprint in green spaces, as the total amount of fresh water required to maintain green space throughout the year, is one of the indicators by which the compatibility of tree and plant species with climatic conditions can be assessed. The main object of this study is to estimate the water footprint of Laleh Park in Tehran province of Iran. The Green space soil water balance (SWB) model was used to calculate water footprint in this park. The required data that including: average daily temperature, total precipitation and moisture depth of zero to 30 cm of soil, were obtained from the Geophysical meteorological station of Tehran for 2018. Data related to soil water drainage were also estimated based on standard laboratory samples of green space soils. The results indicated that in the warm months (June to September) of the year, the total water footprint of Laleh Park in Tehran was 4 to 5 thousand cubic meters per month (m3/m), while the winter months (December to March) total estimated water footprint were less than 1400 cubic meters per month. The generalization of 30 Centimeters depth soil moisture data of the geophysical meteorological station to Laleh Park, released that, in the warm month of the year, Green Water (groundwater or surface water) had the largest portion (more than 90%) in the water footprint of Laleh Park, While in the winter months (December and to march), the green water (water from snow and rain) is main participant in providing soil moisture, more than 90% of the total water footprint of Laleh Park has related to this source.
Shamsallah Asgari, Tayeb Razi, Mohamadreza Jafari, Ali Akbar Noroozi,
Volume 0, Issue 0 (3-1921)
Abstract
Due to the importance of forests in natural and anthropogenic environment, the effects of meteorological drought on the dryness of oak forests in Ilam province were investigated. The main purpose of this study was to determine the relationship of Zagros forests with drought occurring in the area. The results of the Standard Precipitation Index (SPI) for the time periods showed that the most drought occurred in 2007, 2008, 2011, 2015 and 2016. Remote sensing data (MODIS images) were used to investigate the vegetation trend (NDVI) of trees during the period 2016–2016. The vegetation trend (NDVI) was significant over the period with the index drought index (SPI) with R2 = 0.9999. Ground harvesting of oak drying points and simulation using Landsat satellite imagery with 15 m pixel output from GIS software showed that 17894 hectares of area forests from 2000 to 2016 were dried and destroyed and prepared with oak forest and integrated layer. The output layers from the drought zoning were shown visually and the statistical analysis was performed in three 5-year time series. The results of these analyzes from 2002 to 2006 showed that the correlation coefficient between meteorological drought and oak drought 96.6% with a coefficient of determination R2 = 0.985, for the time series of 2007 to 2011 the correlation coefficient between scratches Meteorological and oak dryness of 95.4% with R2 = 0.980 and coefficient of correlation for meteorological drought and oak drought of 98.8% and R2 = 0.995 of coefficient respectively. Its fluctuations in time series show the intensity and duration of the drying up of oak forests in the region. According to the results of this study, it is predicted that if the drought goes through this process, 1118.4 hectares of oak forests in Ilam province will be dried and destroyed annually.
Zeinab Mokhayeri, Ebrahim Fatahi, Reza Borna,
Volume 0, Issue 0 (3-1921)
Abstract
To conduct this research, first, the data of monthly observations of synoptic and hydrometric precipitation from the National Meteorological Organization and the Ministry of Energy during the 30-year period (2006-2005) were obtained. To examine the prospect of future rainfall changes, the historical data of the period (1976-2005) and the simulated climate data of the period (2050-2021) using two models of CM3), (CSIRO-Mk3.6 from the series) Models (CMIP5) and according to 4 scenarios RCP2.6, RCP4.5, RCP6 and RCP8.5) that are available with a spatial resolution of 0.5 x 0.5 with the BCSD method have been used.Mean-based (MB) strategy has been used to correct the bias in the output of these models. The results of the AOGCM models showed that the CSIRO-Mk3.6 error coefficient was less than the GFDL-CM3 model for simulating precipitation in the case of Large Karun.The average future rainfall (2021-2050) in the whole basin compared to the average observed rainfall during the statistical period of 1976-2005 shows, in both models and scenarios in both basins in terms of amount and area of precipitation is decreasing significantly.Heavy rains in the Greater Karun Basin have been concentrated in all scenarios and models east of the basin. The highest rainfall was in the central foothills. The lowest rainfall is in the southwest and southeast. The final results of the present study are expected to be 83-116 mm. Both models are expected to have the highest rainfall in the Greater Karun Basin, with two scenarios: rcp4.5 and rcp2.6.
Mohammad Baaghideh, Motahhareh Zargari,
Volume 0, Issue 0 (3-1921)
Abstract
Broiler is one of the most common sources of poultry meat which has become one of the most popular and fastest poultry production in the world. The performance of broilers is directly affected by increasing or decreasing temperature and heat & cold Stress. In this study, it has been attempted to evaluate the cooling and heating degree-days (HDD and CDD) at different broiler breeding periods for Khorasan Razavi province. For this purpose, monthly mean temperature data for the statistical period (1988-1998) derived from 13 synoptic stations of the province were used. The cooling and heating degree-days were calculated for each of the breeding weeks based on specific thresholds and their spatial distribution was assessed. In the next step, the relationship between the cooling and heating degree-days and geographical parameters were evaluated. The results showed that with increasing latitude, the cooling degree-days decreased and the heating degree- days increased. The northern and western regions of the province have shown greater heating requirements in all broiler breeding periods, while the cooling requirements at different stages of broiler breeding have been higher for the eastern and southern regions of the province. In terms of total cooling and heating requirements, the northeast, southwest and western regions of the province; the cities of Khaf, Gonabad, Kashmar, Sarakhs and Sabzwar have the least heating-cooling requirements in the six-week broiler breeding period and are considered suitable climates for the development of this economic activity.
Zeinab Ebrahimighalelani, Dr Javad Khoshhal Dastjerdi, Dr Hojatolah Yazdanpanah,
Volume 0, Issue 0 (3-1921)
Abstract
plants needs a certain amount of heat at the time of planting and during its growth period, The temperature requirements of the 704 single-cross cultivar of maize in Moghan weather conditions have been found in this study to determine its temperature requirements in its different growing stages in order to investigate the feasibility of its planting in the north west regions of Iran. Daily weather statistics presenting the minimum, maximum and average temperature of 51 Synoptic stations from Meteorological Organization of Iran have been used in this study, their statistical periods range from 1 to 30 years (1365-1395), the statistics and information about 5 main phenology stages of 704 single-cross variety maize which are recorded continually in Agricultural Weather Service of Moghan station in Pars Abad from 1390 to 1391 are provided. Then the 15-day averages from April 21st to July 22nd is obtained. The relationship between the temperature and the height in the linear regression is calculated .Map of heat supply date for seed sowing in all stations from the first half of May was drawn in the GIS. The plant collective growth degree days and the number of days in every phenology phase are calculated for all of the stations and the related maps are plotted.Then,the final map plotted by combining the layers thermal, height, slope and land use in the study area. The results of this study only 27.6% of the study area is able of maize cultivating.
Farzad Shirzad, Mr Bohlol Alijani, Mehry Akbary, Mohammad Saligheh,
Volume 0, Issue 0 (3-1921)
Abstract
Climate change and global warming are very important issues of the present century. Climate change process, especially temperature and precipitation changes, the most important issue is environmental science. Climate change means a change in the long-term average. Iran is located in the subtropical high pressure zone in arid and semi-arid regions and the Hyrcanian forest is a green area between the Caspian Sea and the Alborz mountain range. At the 43rd UNESCO Summit, the Hyrcanian forests were registered as the second natural heritage of Iran. Beech is one of the most important tree species and the most industrial species of Hyrcanian forests It accounts for about 18 percent of the northern forest volume (from Astara to Gorgan with a life span of about 250 years). The study area is located in the Shanderman basin in western Guilan province. In this research using tree dendroclimatology, Use of vegetative width of beech tree rings, Weather station statistics located in the study area, And Mann-Kendall nonparametric statistical method, To Investigate Climate Change Trend on Growth Time Series and Pearson Statistical Method, in order to evaluate the correlation of diameter growth of beech tree rings with climate variables in the region, an attempt was made. Results of time series of beech tree growth rings over 202 years. Using the nonparametric method Mann- Kendall showed, Changes in growth rings of beech trees have a downward and negative trend, at level 5 %, it was significant. Temperature Minimum, Average, Maximum, and Evaporation during the growing season, there was an upward trend and Annual precipitation there was a downward trend. Using the Pearson method Fit correlation of growth ring diameter with temperature, For the average monthly in February and the average minimum temperature in July, August and September and Negative correlation, for average maximum temperature in February, July, August and September at 95% level, it was significant and precipitation in June, the correlation was 95% positive and significant.
Hamzeh Alizadeh, Mehry Akbary, Zahra Hejazizadeh, Mohamad Ahmadi,
Volume 0, Issue 0 (3-1921)
Abstract
Kermanshah province, especially Ravansar city is one of the important regions of the country in the agricultural and horticultural sector, most of the time the hail phenomenon causes significant damage to these sectors. One way to reduce this damage is to install an anti-hail system. To achieve this goal, 37 station hail data were clustered and three main clusters were obtained representing hail days; Each of the clusters has been plotted and analyzed in terms of geopotential height of 500 hPa, moisture level of 700, and map of 1000 to 500 hPa of temperature and omega. The results of the study of hail patterns show; A low-altitude system is essential in the Middle East; To direct hot and humid air from the southern offerings to the region; At the same time, it is necessary to have high instability and weak static stability in the atmosphere on the surface of the earth, as well as the presence of sufficient moisture that can provide showers. Hierarchical analysis (AHP) method was used for location in GIS environment and parameters such as (slope, slope direction, temperature, humidity ...) were evaluated. These criteria were classified as operating maps, each separately and were scored according to the degree of priority in establishing the device. The final map shows the location of the system: Parts of the northwest of the region (Mansour Aghaei and Ghori Qaleh) and northeast of the central part of Ravansar and parts of the southwest of the area due to the appropriate geographical conditions and appropriate to them, sufficient temperature and humidity and the direction of the southwest slope, and having Favorable conditions for severe instability followed by hail; Anti-hail system is very important for construction in these areas. In general, about 32.6 square kilometers have relatively favorable conditions and about 3 square kilometers have very favorable conditions for the construction of the system.
Rastegar Mohammadi, Mohammad Saligheh, Mohammad Hossein Naserzadeh, Mehri Akbari,
Volume 0, Issue 0 (3-1921)
Abstract
Extratropical cyclones according to the frequency, duration, and intensity, the major cause of mid-and high-latitude precipitation across the Mediterranean during winter and autumn. For this research using network data of ECMWF climatic variables with 6-hour time resolution and 0.25 × 0.25 spatial resolution from1979-2016 and were used of 4 Basin stations precipitation data from the Asfezari database from 1979-2016. The results showed that the first pattern is the Mediterranean trough pattern which has the highest frequency of 42%. In this pattern, the low-level due to the presence of a high-level that acts as a barrier have caused the deepening of the Mediterranean low-level and its axis extends to the Red Sea, and due to the collision of low-level and high-level on the region, instability is intensified and has caused the most rainfall among the patterns. In contrast to the first pattern, The fourth pattern has the lowest frequency of 10% Which is the trough pattern of western winds which is located on the Caspian Sea but due to high-level in the south of the region has prevented the entry of low-level and is located in the northern part of the study area due to this, the isobar in the north of the region have become orbital as a result, fewer cyclones enter the area, resulting in less rainfall between patterns. The results also showed that the frequency of cold-core cyclones was 60% in winter and 40% in autumn, but the frequency of hot core cyclones was 62% in winter and 38% in autumn, which in winter, the frequency of hot core cyclones has increased compared to cold-core cyclones, while in the fall the frequency of hot-core cyclones has decreased compared to cold-core. In the last decade, both the frequency of occurrence of cyclones and their intensity has decreased compared to the last two decades. In terms of cyclogenesis places, the western part of the study area has always been active, And with the onset of the cold season from autumn to winter, cyclogeneses places are gradually becoming more active.
Ms Asieh Asgari Dastnaei, Dr Amir Gandomkar, Dr Morteza Khodagholi,
Volume 0, Issue 0 (3-1921)
Abstract
Teleconnection patterns represent large changes that occur in the pattern of atmospheric waves and tornadoes and affect temperature patterns in large areas and are also used to predict average weather conditions over time periods, usually several months or annually. In this study, the effects of 26 Teleconnection patterns with the average monthly maximum temperature on a quarterly and annual basis were investigated. In this study, 4 synoptic stations of Borujen, Shahrekord, Lordegan and Koohrang in Chaharmahal and Bakhtiari province were analyzed. Data were analyzed using descriptive statistics, correlation and Mann-Kendall test. The results showed that the patterns of PNA, WP, NAO, SOI, TNA, TSA, WHWP, Niño 4, NP, Trend, AO, AAO, AMO, AMM, NTA, CAR and GMLO have a positive relationship with all stations studied and The patterns of EA WR, Niño 3, ONI, MEI V2, Niño 1 + 2, Niño 3.4 and TNI had a negative relationship with all studied stations.
Dr Hassan Kharajpour, Dr Zahra Hejazizadeh, Dr Bohloul Alijani, Dr Mohammad Hossein Nasserzadeh,
Volume 0, Issue 0 (3-1921)
Abstract
Considering the undeniable impact of agricultural plants on climatic and regional changes, it seems necessary to conduct regional research to understand the reaction of each agricultural plant in different stages of growth in relation to weather elements. If the temperature of the air along with the warm cloud is lower or higher than a certain threshold, its development will stop. Between the two limits, there is an optimal temperature where the plant grows the fastest. Temperature and clouds are both the most important climatic elements in agriculture. Both climatic parameters together cause stress in wheat and lower the productivity of the product. Considering the strategic nature of wheat, in order to increase the level of production, in the present research, while taking advantage of the experiences and methods and models used in foreign and domestic researches, it was practical in Kermanshah province due to the extent of the land under wheat cultivation and The significant amount of production, which has a special place in this field at the level of the country, the determination of the statistical threshold and the synoptic analysis of warem cloud temperatures on the performance of the wheat crop are investigated. According to the investigations and consultations with agricultural engineers, the maximum temperature along with cloudy days causes the phenomenon of greenhouse and excessive heat, which causes the fall of flowers, rot, sterility of pollen grains, fruit reduction, Premature aging and poverty become seeds, and this phenomenon occurs mostly in the months of May and June.
Toba Alizadeheh, Majid Rezaie Banafsh, Gholamreza Goodarzi, Hashem Rostamzadeh,
Volume 0, Issue 0 (3-1921)
Abstract
Dust is a phenomenon that has many environmental effects in various parts of human life, including: agriculture, economy, health and so on. The purpose of this study is to investigate and predict the dust phenomenon in Kermanshah. Meteorological data with a resolution of 3 hours in the statistical period (2020-2000) of Kermanshah station was obtained from the Meteorological Organization. First, the dust data were normalized and then using ANN neural network models to predict dust concentration and ANFIS adaptive neural network to debug and predict the time series of dust occurrence in MATLAB software were debugged and predicted. Findings showed that the maximum predicted dust concentration related to the minimum fenugreek point with the highest Pearson correlation with dust was estimated to be 3451.23 μg / m3. Also, the results of time series prediction using ANFIS model showed that the linear bell membership function with grade 3, in the training and testing stages, has the most desirable input function among other membership functions. According to the forecasting models, the highest probability of maximum dust occurrence in the next 20 years in Kermanshah was 94%.
Mahnaz Sadeghi, Zahra Haejazi Zade, Mohhamad Saligeh,
Volume 0, Issue 0 (3-1921)
Abstract
The purpose of this study is to increase awareness and flexibility towards climate change and its effects on the environment through education. In the first step, to achieve the reproduction of climatic data and compare the scenarios of the general circulation model of the atmosphere, three important climatic parameters including precipitation, minimum temperature and maximum temperature were used and also SDSM software was used to predict the data. In this study, two stations of Zabol and Chabahar were used during the statistical period of 1961-2005. Three scenarios of RCP2.6, RCP4.5 and RCP8.5 in the period 2020-2050 were used to compare the results of the CanESM2 general circulation model, which is mentioned in the fifth IPCC report. The results of CanESM2 model showed that the minimum and maximum temperature and precipitation in the studied stations will have an increasing and decreasing trend in the future, respectively, in other words, the effects of climate change will be more obvious. In the second step, a questionnaire was distributed to teachers and students in Zabol and Chabahar in the education department; The results of validation of Cronbach's alpha test indicate that this questionnaire had good validity and reliability. The selection of the statistical population was purposeful; That is, from all the related schools, schools were purposefully selected at the discretion of the professors and were also evaluated and questioned. Analysis of the results of questionnaires related to teachers and students showed that the research hypothesis was confirmed according to T-Test.
Moslem Seydi, Kamal Omidvar, Gholamali Mozafari, Ahmad Mazidi,
Volume 0, Issue 0 (3-1921)
Abstract
Abstract
Climate change is an important environmental issue because the melting processes of glaciers and snow density are sensitive to climate change. Today, a variety of satellite sensors such as AVHRR, MODIS, GEOS, MERIS are available for snow monitoring and are widely used to investigate and investigate the fluctuations and changes in snow cover globally. Modis sensor has been considered more because of its global spatial coverage with suitable spatial accuracy and frequent temporal coverage on different scales , Therefore, in the present study, snow products of this sensor were used. In this study, after collecting statistics and data on snow-related days during the statistical period (1989-2018) in three provinces of Kermanshah, Ilam and Lorestan, they were processed using Modis snow cover data in middle Zagros as well as remote sensing techniques, Finally, the snow cover changes in the study area were studied in detail. NDSI index was used in MODIS sensor products to detect snow cover. Consequently, in order to differentiate pixels and identify different phenomena, the received images were processed in GIS environment. . Investigation of snow cover changes in different seasons using Modis sensor images shows that most of the studied area has a significant decreasing trend, especially in the elevated areas of the study area And only in the western and southwestern regions of the study area, there is no specific decreasing trend. Also, the study of snow covered days during the study period indicates a decrease in middle Zagros snow cover and these changes have been intensified in recent years, especially in snow-covered areas of the region. Also, changes in winter and snow-capped and elevated areas were more and more severe than other seasons and other regions in the study area.
Shahram Emamgholi, Gholamrezaa Janbaz Ghobadi, Parviz Rezaei, Sadroddin Motevali,
Volume 0, Issue 0 (3-1921)
Abstract
Temperature is one of the basic elements of climate, so its sudden or short-term and long-term changes can change the climate structure of any place. Intense heat waves are one of the most important climatic disasters that have far-reaching effects on various human activities and when they are of high intensity and frequency, they can produce major problems. In this study, to investigate the trend of 49-year frequency series (1970-1970) of hot wave events in Tehran, from two indices of hot days and hot waves (hot days lasting 2 days or more), non-parametric statistics of Sens trend analysis were used. All stations indicate an increasing trend both in the number of hot days in Tehran and in the frequency of hot wave events in 5 stations in Tehran. In this study, two hot waves were identified in Tehran, the first wave in 2010 covered a large part of the central and western parts of the country and the second wave in 2013, which was in all stations of Tehran and even many provinces. Are registered in the country. The results of spatial analysis of hot wave temperature in the statistical blocks of Tehran showed that generally the central areas of Tehran, including areas 6, 7, 8, 10, 11, 12, 14, 15, 4, 7, and 19 significantly It has been affected by the critical temperatures caused by the warm wave rule, while the northern parts of Tehran have been affected by the lower intensities of the hot wave.
Mr Ebrahim Bairanvand, Dr Amir Gandomkar, Dr Alireza Abbasi, Dr Morteza Khodaghoi,
Volume 0, Issue 0 (3-1921)
Abstract
The occurrence of torrential rains in April 2017 in Lorestan province was a clear example of heavy rains that left very heavy damage to agricultural, urban, transportation and communications infrastructure. The purpose of this study is to investigate and reveal the relationship between the physical structure of clouds producing two waves of heavy rainfall in April 2017 in the Doroud catchment area of Boroujerd. In this regard, the statistical characteristics of two precipitation waves on March 25 and April 1, 2019 were analyzed. The supernatural properties of the clouds producing these two heavy rainfall waves were investigated using the Madis superconductor product, MOD06. 4 Microphysical factors of generating clouds These two waves of heavy rainfall in the Doroud-Borujerd basin, including cloud peak temperature (CTT), cloud peak pressure (CTO), optical cloud thickness (COT) and cloud cover ratio (CF) were analyzed. Statistics of these two waves of heavy rainfall showed that in the first wave of heavy rainfall, ie the wave of March 25, 2019, (5 April 1398) 15% of the total annual rainfall and in the second wave, the wave of April 1, 2019 (April 12, 1398) 20% of the total The total average annual rainfall of the region was recorded in these two days. The results of analyzing the microphysical structure of the generating clouds of these two precipitation waves using the MODSI cloud sensor product data showed that the four microphysical factors of the cloud showed a significant spatial correlation with the recorded precipitation values of these two heavy precipitation waves. The two factors of temperature and pressure of cloud peak, which show a vertical expansion of clouds in the area, showed a significant inverse relationship with the amount of precipitation in the basin, while the two factors of cloud ratio and cloud optical thickness have a direct and significant spatial correlation with values. Recorded rainfall showed. The results of this study showed that in these two events of heavy rainfall, a significant and strong relationship was established between the microphysical structure of the cloud and the amount of rainfall recorded in the region.
Mostafa Karampour, Yeganeh Khamoshian Sahneh, Zohreh Ebrahimi, Hamed Heidari,
Volume 0, Issue 0 (3-1921)
Abstract
In recent years, much attention has been allocated to the study of atmospheric rivers because atmospheric rivers are massive carriers of moisture from remote areas. In this study, atmospheric rivers were studied for Iran and the neighboring countries in terms of their source of formation and their relationship and correlation with the NAO index. To study them the 1994 to 2019 data of various climatic elements such as Vwind, Function wind, NAO,, wind Shum, Meridonal wind were used. The results showed that during the study period, the ARs direction became more southerly, and jet streams played a major role in producing and determining the direction of river flow. Jetstream performance can also be used to determine the potential of an area in identifying atmospheric rivers. The highest correlation of the Transatlantic Transplant Index is with the tidal currents at the levels of 500 and 400. If the pressure centers are located in the southern part of the atmospheric rivers and the jet streams reach the eastern regions about 60 degrees, the length of the atmospheric rivers will reach more than 12,000 kilometers and affect the eastern regions of Iran to Pakistan, Bangladesh and Afghanistan.
Doc. Zahra Ghassabi, Doc. Hoshang Ghaemi, Mr. Ebrahim Mirzaei,
Volume 0, Issue 0 (3-1921)
Abstract
The structure of deep moist convection can be influenced by wind shear, available potential energy of convection, relative humidity and vertical distribution of each of these variables, along with other effective factors, among which wind shear plays a more important role in creating convection. Due to the large and synoptic scale processes, along with the adjustment of the available potential energy for convection and the convection inhibitor, create suitable conditions for the creation of convection. The role of the large-scale average causes the reduction of the convection inhibitor, but the vertical velocity of even a few centimeters per second can have an obvious effect on the environment sounding. Also, the presence of potential instability is usually considered an important factor in the initiation of deep moist convection. It can be seen that when the temperature reaches the critical point and the convection inhibitor is removed, moist deep convection begins. In the case that the air parcel that rises above the lower stable layer may have a low relative convective inhibition energy and a high relative free convective potential energy, which causes the support of deep moist convection. The warm air mass continues the initiation of updrafts, and the subsequent development of convection depends on parameters such as vertical wind shear and the inversion cap of the environment, among other parameters. Large-scale convective systems can be released with less forcing due to the massive rise of the air mass on the surface of the front to the level of convection.
Mohammadsaleh Ekhlasi, Dr. Somayeh Soltani-Gerdefaramarzi, Dr. Abolfazl Azizian, Morteza Gheysouri,
Volume 0, Issue 0 (3-1921)
Abstract
In this research, the effect of climate change on the amount of virtual water of some strategic crops was investigated in Kerman province for future periods. For this purpose, the climatic data of HadCM3 model was used under RCP4.5 radiative forcing scenario. In order to investigate the possibility of producing and simulating meteorological data in the future periods, was applied the LARS-WG microscale-representative model. For the basic period (1991-2011), was done calibration and validation of the model. Through the data of LARS-WG, the amount of precipitation and the maximum and minimum temperature of the selected stations were predicted for the periods of 2011-2070 and compared with the base period. Virtual water amount was calculated for selected crops including alfalfa, barley and wheat. The results of the current research indicate that the phenomenon of climate change significantly affects the evapotranspiration and the performance of the studied crops, and hence it will affect the agricultural water productivity in the future. While the average temperature of the growing season will increase in the future under the influence of climate change, the maximum temperature parameter will be affected by this phenomenon more than the minimum temperature, and parallel to this, the water requirement and plant evaporation-transpiration will increase in this period. Also, the surveys show a decrease in precipitation in the hot seasons and an increase in the cold seasons in all study stations. The amount of virtual water changes obtained for all studied plants is increasing, and this increase for barley and wheat crops shows a greater increase on average in the future period. The biggest increase in the virtual water compared to the base period in Kerman station is related to barley and alfalfa products by at least 30%.
Miss Sorayya Derikvand, Dr Behrooz Nasiri, Dr Hooshang Ghaemi, Dr Mostafa Karampoor, Dr Mohammad Moradi,
Volume 0, Issue 0 (3-1921)
Abstract
sudden stratospheric warming has an obvious effect on the Earth's surface climate. In this research, the changes in precipitation during the occurrence of this phenomenon have been investigated. For this purpose, after revealing the warmings that occurred during the studied period (1986-2020), 18 warmings were identified. The 5th decile and 9th decile of precipitation were calculated for the precipitation data of 117 stations. And the size of the difference from the normal rainfall was checked in two ways. First, the precipitation at the time of warming was compared with the long-term average, and then the trend of changes in precipitation at three times before thewarming, at the same time as the warming, and after the warming was finished. Finally, these results were obtained. Warmings according to the month in which they occur; They have a different effect on the amount of precipitation. In the sudden stratospheric warming that occurred in December, January and February, the northwest experiences the most rainfall changes and is above normal, and the probability of rainfall above the 9th decile increases up to 65%. Western and southwestern regions also have higher than average rainfall and the probability of heavy rainfall is high. Precipitation on the shores of the Caspian Sea shows an inverse relationship with sudden stratospheric warming, so in all the investigations of this research, the lack of precipitation at the time of warming in these areas is significant. Southern regions have less than normal rainfall in all sudden stratospheric warming events. The center of Iran has higher than average rainfall in the sudden stratospheric warming months of March. Eastern Iran also has heavy rains compared to normal during the sudden stratospheric warming months of March.
Zohreh Maryanji, Fatemeh Sotoudeh, Meysam Toulabi Nejad, Ziba Zarrin,
Volume 0, Issue 0 (3-1921)
Abstract
Understanding and predicting future climatic conditions and characteristics is essential because of their importance in all aspects of life. This study seeks to examine the process of modifying temperatures in the Hamedan region by using Downscaling data to predict the public circulation data and its changes. The Lars Explore Downscaling Model has been used to fine-tune the data of the General Transport Model (HADGEM2-ES) and the paired model (CMIP5) and under the three release scenarios RCP2.5, RCP4.5, and RCP8.5). Estimates of the correlation of simulated data and actual data show values of more than 0.95 for all months. P_value also showed the statistical tests of model output, acceptable values in model performance in production and simulation. As a result, the data were extracted from 2011 to 2050. Data were examined in three intervals to detect trend changes. The results show that in the optimistic scenario (RCP2.5) there is no tangible trend in the mean and minimum temperature, while in the RCP4.5 and RCP8.5 scenario there are significant trends in temperature data and accordingly increase the minimum temperature, according to the increase in the minimum temperature, according to the increase in the minimum temperature, according to the increase 1 degree in the average temperature. It shows severe climate change that, especially in the cold season, changes the type of precipitation. Also, based on the data process, the significant increase in the average annual and monthly scale temperature in all three scenarios under study will indicate the environmental crisis ahead.
