Climatology
vahideh abtahi; Saeed jahanbakhsh; hashem rostamzadeh; hasan lashkari
Abstract
Heavy rainfall is considered one of the climatic features of precipitation that can occur in any climate, but its occurrence in arid and semi-arid climates, due to the lack of adequate and appropriate infrastructure, is associated with greater damage. These rains occur under different synoptic conditions. ...
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Heavy rainfall is considered one of the climatic features of precipitation that can occur in any climate, but its occurrence in arid and semi-arid climates, due to the lack of adequate and appropriate infrastructure, is associated with greater damage. These rains occur under different synoptic conditions. In this study, the role of atmospheric rivers in the formation of heavy rainfall has been investigated. For this purpose, heavy rainfall data from stations in the west and northwest of the country were extracted for a 33-year period. Then, precipitation systems were separated in conjunction with atmospheric rivers. In the next step, using weather maps and the troposphere's underlying layer levels, synoptic patterns that lead to the formation of atmospheric rivers were identified. The results showed that atmospheric rivers were responsible for heavy rainfall in the study area, following three general patterns. The Sudanese low-pressure pattern and the combined pattern of Sudanese low-pressure and Mediterranean cyclone were responsible for the most significant role in the formation of atmospheric rivers leading to heavy rainfall, respectively. In the Sudanese low-pressure pattern, two to three days earlier, a broad tongue of Siberian high pressure spreads over the warm waters of the Oman, Arabian, and Aden seas, passing through Afghanistan, Pakistan, and the eastern part of Iran. This tongue, with the rotation of moisture, escapes from the Sudanese system. The Mediterranean trough deepens over western Asia and northeast Africa, and this moisture is strengthened along the southern currents and, by passing over the mountains,leads to the formation of atmospheric rivers. In the combined pattern, with the expansion of the Sudanese low-pressure tongue to the eastern Mediterranean and western Asia, the southern warm waters' moisture is released onto this region with the transport of moisture from the Mediterranean, it is strengthened, leading to the formation of atmospheric rivers.
Climatology
Narges Samadi; Ali akbar Rasouli pirouzian; Davood Mokhtari; Khalil Valizadeh Kamran
Abstract
The main aim of the current study was to detect changes in snow cover within the Western watersheds of Lake Urmia, situated in the Silvaneh mountain range, using the processing of multi-sensor and multi-spectral satellite images for high-precision identification of snow-covered areas. Sentinel-2 and ...
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The main aim of the current study was to detect changes in snow cover within the Western watersheds of Lake Urmia, situated in the Silvaneh mountain range, using the processing of multi-sensor and multi-spectral satellite images for high-precision identification of snow-covered areas. Sentinel-2 and Landsat (8 and 9) satellite images were acquired and underwent preprocessing operations, such as atmospheric and radiometric corrections, using ENVI software version 1/10. Projects for the May months of the years 2016 to 2023 were then established. Initially, normalized difference snow indices were employed to independently generate snow cover maps for Landsat and Sentinel images for the entire watersheds of Nazluchay, Ruzechay, Shahrchay, and Barandozchay. In the next stage, an optimized color-sensitive object-based approach, based on object-oriented functions, was applied to the main bands of the Sentinel-2 sensor. To enhance the accuracy of the final results, Landsat images were fused with Sentinel images through a coordinated fusion method, producing various products, especially high-resolution optimized color images and classified scene maps. Ultimately, high-precision snow cover maps for temporal series were extracted for each of the mentioned watersheds through processing the fused images. Examination of the snow cover maps revealed that despite its smaller area compared to the Nazluchay and Barandozchay watersheds, the Shahrchay watershed has a higher snow accumulation coefficient, allowing for greater snow cover storage. Additionally, the comparison of the snow cover density map (years 2016 to 2023) with the elevation model of Alouspalsar at a resolution of 5/12 meters indicates a significant distribution of snow cover in higher elevations above 2300 meters in the study area. Therefore, accurate identification of snow cover, even on a daily and weekly scale, can provide essential and precise information for proactive water resource management, resulting from snowmelt, with multiple objectives in the watersheds surrounding Lake Urmia.
Climatology
Paria Saadatjoo; Ali Alizadeh; Saeed jahanbakhsh; Ali Mohammad Khorshiddoust; Behrooz Sari Sarraf
Abstract
This article investigates the impact of climate change on energy consumption in residential buildings across various Iranian cities over the next 70 years.
To achieve this, climatic data for Tehran, Tabriz, Isfahan, Mashhad, and Kermanshah were generated using Meteonorm 8 software based on existing ten-year ...
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This article investigates the impact of climate change on energy consumption in residential buildings across various Iranian cities over the next 70 years.
To achieve this, climatic data for Tehran, Tabriz, Isfahan, Mashhad, and Kermanshah were generated using Meteonorm 8 software based on existing ten-year climatic data. Following the identification of prevalent residential building types in Iran, a representative sample was selected, and energy simulations were conducted using Design Builder 7.0.0.096 software for the years 2030, 2060, and 2090 in the aforementioned cities.
The results indicated a projected increase in cooling energy demand across all cities in the coming years. Tehran exhibited the most significant changes in annual heating energy, with a projected decrease of 37% in 2060 and 66.64% in 2090 compared to 2030. Tabriz experienced the largest annual increase in cooling energy, with a rise of 37.53% in the first three decades and 75.43% in the subsequent three decades. Overall, projected annual cooling energy changes ranged from 21.36% to 37.53% by 2060 and 44.14% to 75.43% by 2090 across these cities.
Tabriz had the highest annual energy consumption, while Kermanshah had the lowest. Additionally, Tabriz exhibited the highest heating energy consumption, whereas Tehran had the highest cooling energy demand annually. Regarding carbon dioxide emissions, Tehran recorded the highest levels during 2030, 2060, and 2090, with Isfahan showing the most substantial increase in emissions over the seventy-year period. Statistical analyses revealed a significant relationship between temperature changes and time across all cities. However, no significant relationship was found between time and energy consumption or carbon dioxide emissions in these cities. In conclusion, this study highlights the anticipated changes in energy consumption and carbon dioxide emissions in residential buildings across Iranian cities due to climate change.
Climatology
Mahnaz Saber; Bromand Salahi; Roghayeh Maleki Meresht
Abstract
In this research, the water balance components of the Aras basin area were simulated in the SWAT model for a period of 28 years (1987-2014). For this purpose, the efficiency and capability of the SWAT model by SWAT CUP using the SUFI2 algorithm and based on the observed discharge data in the selected ...
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In this research, the water balance components of the Aras basin area were simulated in the SWAT model for a period of 28 years (1987-2014). For this purpose, the efficiency and capability of the SWAT model by SWAT CUP using the SUFI2 algorithm and based on the observed discharge data in the selected hydrometric station of Aras basin (Bdoy) with 70% of the data (1987-2006) and 30% of the rest (2007-2014) was validated. Based on the raster data input to the model, this basin was divided into 68 subbasins with 1264 hydrological response units (HRUs) and calculations were performed on their level. SWAT model calibration was done by using 14 important parameters that were selected from several parameters based on the comparison of sensitivity analysis results. In the sensitivity analysis stage of the model, parameters related to monthly temperature, air temperature, and soil evaporation factor from.bsn,.wgn, and.hru files were identified as the most effective parameters in simulating the flow discharge of the selected hydrometric station of Aras Basin. By running 300 times of calibration, finally, the best round of simulation based on the target criteria was identified and the output data was evaluated. The efficiency and accuracy of the model in the calibration period (1987-2006) based on the evaluation criteria of NS, P-Factor, R-Factor, and R2 were calculated as 0.64, 0.71, 0.27, and 0.79 respectively, which show the satisfactory performance of the model. In the water balance simulation, it is Aras Basin. The values of these criteria in the validation period were calculated as 0.7, 0.78, 0.3, and 0.68 respectively.
Climatology
مهدی Asadi
Abstract
In this study, we aimed to predict the trends of climatic parameters affecting almond growth from 2021 to 2100. We utilized the IPSL-CM5A-LR and GFDL-ESM2M models from the CMIP5 report, as well as the GFDL-ESM4 and IPSL-CM6A-LR models from the CMIP6 report. These models were selected based on their high ...
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In this study, we aimed to predict the trends of climatic parameters affecting almond growth from 2021 to 2100. We utilized the IPSL-CM5A-LR and GFDL-ESM2M models from the CMIP5 report, as well as the GFDL-ESM4 and IPSL-CM6A-LR models from the CMIP6 report. These models were selected based on their high coefficient of determination (r^2) with temperature and precipitation data from the Birjand station, outperforming the other 10 models. Kendall's rank correlation test results revealed that the average, maximum, and minimum temperatures exhibited an increase of over 3 degrees Celsius, while precipitation showed a decreasing trend. These findings suggest a prevalence of dry conditions during the study period from 2021 to 2100. Furthermore, the climate models showed that the RMSE (Root Mean Square Error) and MAD (Mean Absolute Deviation) values for temperature in all the examined models were below 1.322. The GFDL-ESM2M model displayed the lowest RMSE and MAD values, with numerical values of 1.023 and 0.997, respectively. However, all models' RMSE and MAD values for precipitation were above 10. Overall, the CMIP6 models (RMSE for temperature and precipitation: 1.156 and 14.463, MAD for temperature and precipitation: 1.139 and 12.583) performed better in predicting temperature and precipitation in the study area, exhibiting lower mean errors compared to the CMIP5 models. The only exception was the MAD value for precipitation 11.703 (RMSE for temperature and precipitation: 1.172 and 13.479, MAD for temperature and precipitation: 1.140 and 11.703). Finally, due to the increase in minimum and maximum temperatures and decrease in precipitation, the future conditions of the crops are facing a challenge.
Climatology
Ali Zarei; Asadollah Khoorani
Abstract
The study aimed to introduce the most effective model for estimating energy consumption through the modeling of residential electrical energy consumption. .Reanalysis climate data from ECMWF spanning the years 2003 to 2022 were acquired, along with the annual electrical energy consumption data of the ...
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The study aimed to introduce the most effective model for estimating energy consumption through the modeling of residential electrical energy consumption. .Reanalysis climate data from ECMWF spanning the years 2003 to 2022 were acquired, along with the annual electrical energy consumption data of the residential sector across Iranian provinces. Pearson correlation coefficient was employed to analyze the relationships between variables, and the Mann-Kendall non-parametric test was utilized to scrutinize trends in these variables. Four regression and Artificial Intelligence (AI)-based models, namely Multiple Linear Regression (MLR), Artificial Neural Networks (ANN), Support Vector Machine (SVM), and Random Forest (RF), were employed to model electric energy consumption. The performance of these models was assessed using metrics such as Root Mean Squared Error (RMSE), Coefficient of Determination (R2), and Standard Deviation (SD), evaluated through a Taylor diagram. Provinces. In 22 provinces, a positive correlation was observed, whereas in 9 provinces, a negative correlation was identified. Analysis of the temporal changes indicates a consistent increase in minimum and maximum temperatures as well as electrical energy consumption across all provinces. However, it is noteworthy that the UTCI displayed a negative trend in several provinces. The stepwise regression model revealed that in 23 provinces, the sole influential variable is the minimum temperature. Notably, in the provinces of Isfahan, South Khorasan, and Kerman, both minimum temperature and the UTCI were identified as influential variables. Conversely, in Ardabil, Gilan, and Golestan provinces, only the maximum temperature featured in the regression equation. Modeling outcomes underscored the superior performance of the ANN model in comparison to the other three models. The ANN model exhibited the highest correlation coefficient at 0.79, coupled with the RMSE of 360. Following in ranking, the MLR, SVM, and RF models demonstrated progressively lower levels of performance
Climatology
Mohsen Hamidianpour
Abstract
The city of Mashhad, with a population of more than 3 million people, ranks as Iran's second-largest city. To enhance its resilience against environmental hazards, the adoption of new technologies is increasingly essential. On May 26, 1403, during a 48-minute rain due to the formation of a cumulonimbus ...
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The city of Mashhad, with a population of more than 3 million people, ranks as Iran's second-largest city. To enhance its resilience against environmental hazards, the adoption of new technologies is increasingly essential. On May 26, 1403, during a 48-minute rain due to the formation of a cumulonimbus cloud and the strengthening of its ascending conditions by a Trough on top of it, a flood occurred in the city of Mashhad led to heavy financial and human losses in different areas. This study aims to explore both natural and human factors contributing to the flood through a holistic approach. To analyze the synoptic meteorological causes, data from the ERA-5 and its maps were utilized in GrADS. Additionally, Landsat satellite imagery and digital elevation data were employed to identify waterways and canals. Google Earth and GEE software were also used to assess changes in the landscape. The results showed that in terms of intensity and duration of rainfall, the rainfall was unprecedented rainfall, and according to the threshold of 95% percentile, it is considered as extreme rainfall category (above 95% percentile). The results of this study clearly show that human encroachments, especially in urban construction and the expansion of urban roads and highways perpendicular to the seasonal and dry rivers of the city, have strongly affected the water flow pattern and increased the risk of floods. The neglect of urban geomorphology, including the destruction of natural water pathways, the construction of barriers against water flows ways like those in the Seyyedi region, and the expansion of roads perpendicular to these waterways, was intensified flooding issues in various areas in Mashhad city.
Climatology
Maryam Teymouri; Bromand Salahi; Mohammad-Ali Nasr Esfahani
Abstract
To study the cyclogenesis within the Mediterranean region in different phases of Madden-Julian Oscillation (MJO) during the cold season (November, December, January, and February) between 1989 and 2020, MJO index and mean sea level pressure data from the European Centre for Medium-Term Atmospheric Prediction, ...
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To study the cyclogenesis within the Mediterranean region in different phases of Madden-Julian Oscillation (MJO) during the cold season (November, December, January, and February) between 1989 and 2020, MJO index and mean sea level pressure data from the European Centre for Medium-Term Atmospheric Prediction, ERA5 section were utilized. For visualizing the frequency, depth, and tracking characteristics of cyclogenesis, the University of Melbourne method was used. The results showed that the strongest cyclones in the region formed in phases 8, 6, and 7, respectively, with a pressure less than 994 hPa. In terms of the frequency of cyclogenesis and the core of cyclones in the region, the highest and the lowest amount of cyclogenesis were related to phase 7 and 1, respectively. The results showed that phases 6 and 7 have the strongest central pressures, whereas phases 1, 3, and 5 have the weakest central pressures of the MJO phases. Phase 2 has the lowest value of central pressure and the highest average pressure is related to phase 5. The tracking of cyclones that formed within the Mediterranean region showed that most of the paths that ended in the western regions of Iran were in phases 2 and 8, whereas in other phases, these tracks had a southwest to northwest direction. These situations were the case during phases 3, 4, 6 and 7, which caused most of the cyclones formed in the cold season of the year to affect most of the north-western regions of Iran.
Climatology
Yagob Dinpashoh; Saina Vakili Azar
Abstract
In this study, storm patterns were analyzed in three rain gauge stations in Gilan province. All the storms were divided into the three distinct classes which are: i) 0-6 hrs, ii) 6-12 hrs, and iii) >12hrs. Analysis performed separately for each of the classes. Huff curves were plotted and the pattern ...
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In this study, storm patterns were analyzed in three rain gauge stations in Gilan province. All the storms were divided into the three distinct classes which are: i) 0-6 hrs, ii) 6-12 hrs, and iii) >12hrs. Analysis performed separately for each of the classes. Huff curves were plotted and the pattern of rainfall identified using the quartile approach. The pattern of storms obtained using an innovation method based on vertical distances of 90 and 10 percent Huff curves and 50% Huff curve (d50) at 25, 50 and 75% of duration. Results showed that most of patterns were the second quartile type. Comparing the V-values, it was found that the V-value of Hashtpar in the less than 12 hours classes was high in all the three durations (i.e. 25, 50 and 75 percent). This indicates that the storms variability in Hashtpar was more than others. In more than 12-hours class, the station Kharajgil at 25 and 50 percent duration shows large value of V. However,, in the station Galeh Rudkhan, the large V observed at 75% time duration. Moreover, results showed that the station Kharajgil had large value of d50 at 25, 50 and 75 percent of durations in the class of 0-6 hours comparing the two other stations. This implies that rainfall intensities at station Kharajgil were more than the two other stations. In the class of 6-12 hours, the large value of d50 at 25 percent of time at station Kharajgil was observed. However, the large value of d50 observed at 50 and 75 percent of duration at station Galeh Rudkhan. At the class of more than 12 hours, the station Kharajgil showed large d50 values in 25 and 50 percent durations. The value of d50 for station Hashtpar in 75 percent duration was large among all the stations.
Climatology
Mahnaz Saber; Bromand Salahi
Abstract
In this research, the drought situation of Aras Basin under the conditions of climate change has been investigated. For this purpose, simulated precipitation data of CNRM-CM6-1-HR model with high horizontal resolution (10 km) under SSP585 scenario during 76 years and 912 months of the future period (2100-2025) ...
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In this research, the drought situation of Aras Basin under the conditions of climate change has been investigated. For this purpose, simulated precipitation data of CNRM-CM6-1-HR model with high horizontal resolution (10 km) under SSP585 scenario during 76 years and 912 months of the future period (2100-2025) were used, and the SPI index was determined as a criterion for evaluating the drought situation. The monthly analysis of the future drought under the SSP585 scenario with the SPI index showed that the drought trend is decreasing in all stations except Jolfa station. Under the SSP585 scenario, the most severe drought of the period was simulated in Ardabil and Ahar in April 2094, in Jolfa in April 2094, in Parsabad in February 2028, in Khoi in September 2078 and in Mako in May 2080. On an annual scale, the frequency of drought in Mako, Jolfa, Parsabad, Khoi and Ardabil was calculated as 42, 41, 39, 36 and 34 years respectively. Spatial distribution of annual precipitation anomalies in Aras basin showed that the maximum of very severe drought and the minimum of very severe wets are located in the southeast of the basin (Ardabil station), while the maximum core of extreme wets and the minimum core of extreme drought are concentrated in the southwest of the basin. On a monthly scale, the core of maximum and minimum frequency of positive anomalies is mainly located in the western half of the basin. On an annual scale, the largest increase in the estimated positive precipitation anomalies was related to Ardabil, Parsabad and Ahar, and the largest decrease in negative anomalies was related to Ahar, Khoy and Ardabil. On a monthly scale, the maximum decrease in negative anomaly is related to Parsabad and the maximum percentage increase in positive anomaly is related to Jolfa.
Climatology
Saeed jahanbakhsh; Majid Rezaei Banafsheh; Alimohammad Khorshiddoust; Hajar Farahmand
Abstract
In recent years, South-east and east of Iran has become one of the most important hotspots of dust events due to numerous droughts, upstream dams and severe land use changes. In order to evaluate the seasonal variations of dust, 15 synoptic stations were selected during 1980–2015 and then extracted ...
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In recent years, South-east and east of Iran has become one of the most important hotspots of dust events due to numerous droughts, upstream dams and severe land use changes. In order to evaluate the seasonal variations of dust, 15 synoptic stations were selected during 1980–2015 and then extracted from the present weather codes. Additionally, the AOD index of the Terra MODIS satellite sensor and the Aura Satellite Aerial Index of Absorption (AAI) were used during the period 2015–2005. Mann-Kendall nonparametric test was used to investigate the trend of dust days and Spearman correlation method was used for correlation of dust days. The average days of dust in this region are 9 days and maximum days of dusty days are 45 days that occur in Zabol station at summer. Intra-seasonal variations of dust over east and southwestern of Iran have two maximum phases at spring and summer. Dust also has an inverse relationship with altitude and latitude. Climate parameters, drying up of rivers and lakes, and land use changes are three major factors in dust production in eastern and southeastern Iran. Main sources of dust production and emission over the region are (1) Makran coast; (2) Hamoun and Jazmourian dried bed (3) Lut Plain and (4) Border region of Iran, Afghanistan and Pakistan. At most stations except Zabul, Bam and Kerman have an increasing trend of dust events.
Climatology
shahriar khaledi; Esmaeil Bakhshi; Mahmoud Ahmadi; Abbasali Dadashi Roudbari
Abstract
From urbanization, the phenomenon of the urban temperature island follows which the city rises and increases from energy to cool. In this research, the role of local factors in the creation and development of heat islands in the city of Ahvaz during the hot period from 2000 to 2015 was investigated using ...
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From urbanization, the phenomenon of the urban temperature island follows which the city rises and increases from energy to cool. In this research, the role of local factors in the creation and development of heat islands in the city of Ahvaz during the hot period from 2000 to 2015 was investigated using Landsat 7 and 8 satellite data. In order to evaluate the biophysical changes of the land surface in Ahvaz city, the changes of vegetation difference indices were taken by Tokanga-Tag threshold method. By using the kriging method and the low speed zones of Ahvaz, the thresholds of the closest and maximum temperature of Ahvaz city, it appears that this change can cause a change in the local climate. The results of Moran's spatial autocorrelation are a confirmation of the lack of spatial correlation of ground surface temperature in Ahvaz. The evaluation of the northern maps showed that as we move from the southern regions to the northern regions, the temperature increases due to the increase of green space and the increase of barren lands. There is a sharp temperature difference between the central and suburban areas of the city, because of the establishment of industrial companies, District 8 has formed the most stable islands in this area of the city. Residential areas have had less impact on the creation and expansion of thermal islands than industrial and barren areas.
Climatology
Ali Mohammad Khorshiddoust; Mustafa Tahani Yazdali; farahnaz khoramabadi; Aazam Samadi; Farideh Ansari Maleki; Mohammad Hossein Pourghorban
Abstract
Problems caused by climate change are one of the most important environmental crises and threats of human society, especially in urban environments. In the city of Tabriz and in recent years, due to the growth of the population, a lot of migration from other cities, traffic, the development of industries ...
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Problems caused by climate change are one of the most important environmental crises and threats of human society, especially in urban environments. In the city of Tabriz and in recent years, due to the growth of the population, a lot of migration from other cities, traffic, the development of industries and production centers have caused an increase in the production and distribution of pollutants. Based on this, in this research, attention has been paid to the evaluation of the quality of dust occurrence in the years 2019 and 2018. The concentration of dust particles in different areas of the studied places varies depending on the geographical location, topographical, climatic conditions and also their origin, both internal and external. Based on the results obtained from the analysis of laboratory results and field studies, in the Tabriz region and during the research period, the concentration of lead metal in dust is moderate for adults and severe for children, and the risk of mercury metal for both the elderly and children. It has been intense. The adverse effects of cadmium metal have been very severe in children and adults. On the other hand, the high air temperature in the city center and the formation of thermal islands in it causes local winds from the suburbs to the city center. With the transfer of pollution from the suburbs to the city center by these winds, the pollution situation in the city center also increases.
Climatology
Hassan Rezaei; Gholamabbas Fallah Ghalhari
Abstract
Understanding the climatic potentials of the regions is very important for the diversity and talent of agricultural products. Barberry, one of the products of Iran, suffers from climate change and anomalies. In the present study, the phonological stages of barberry tree without any basis of field observations ...
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Understanding the climatic potentials of the regions is very important for the diversity and talent of agricultural products. Barberry, one of the products of Iran, suffers from climate change and anomalies. In the present study, the phonological stages of barberry tree without any basis of field observations in Ghaen synoptic meteorological station were determined. To measure the accumulation of cooling needs based on the cold clock model and the Utah unit, the statistics of 18 valid meteorological stations from 1987 to 2017 on an hourly and daily time scale were used. The results showed that barberry needs six phonological stages to complete the growth period from early April to late November. The highest temperature requirement occurs in the ripening stage until fruit development. The cooling requirement of barberry tree in different stations varies from 1050 to 1960 hours depending on climatic conditions. Field observations showed that seedless barberry does not take on a full and commercial color if it does not meet the need for sufficient cooling. The study area was zoned according to the models of the cold clock and the Utah unit, based on which Ghaen and Zahedan stations have the highest cooling needs. Based on the validation indices of different models estimating the need for cooling, the root mean square criterion was used and the results show that the cold hour (CH) model has a higher performance due to the fact that the root mean square (RMSE) is less than the other model.
Climatology
Nafise faghih sabzevari; azita farashi
Abstract
Today, climate change and habitat loss are the biggest threats to wildlife. Therefore, accurate information on ecology and habitat requirements conserve species from these changes and identifying the most important factors to attract species and the development of habitat suitability maps can be considered ...
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Today, climate change and habitat loss are the biggest threats to wildlife. Therefore, accurate information on ecology and habitat requirements conserve species from these changes and identifying the most important factors to attract species and the development of habitat suitability maps can be considered a species protection process. After leopards and cheetahs, Caracal is the third biggest member of the cat family (Felidae) in Iran that has a key role in controlling of rodent populations and its habitat is mostly in arid areas. Accordingly, the aim of this study is to consider the effects of climate change on Caracal habitats and the distribution of the species under two climate scenarios RCP2.6 and RCP8.5 in the period of 2061 to 2080 in Iran by using the maximum entropy method. In this study, four groups of environmental variables are used: climat, topography, land cover, and land use. The results showed that distance from the conservation network, distance from sand dunes, and distance from dense forest areas had the greatest impact on the selection of suitable habitat for the Caracal at the present time and for the future time, the variables of mean temperature of warmest quarter and elevation had the highest importance on the distribution of Caracal. In addition, the study of Caracal's habitat suitability maps revealed that these species currently occupy only 13.2% of Iran, which have only 48.2% overlap with the current conservation network. While, in the future, the desired habitat rate of the species under the scenarios of RCP2.6 and RCP8.5 will be reached 30.9 and 27.4, respectively, and the amount of overlap with the current protected network will be reduced to about 66%, and the amount of overlap will have arrived at 17.8%.
Climatology
Fatemeh Taghavi nia; Batool Zeinali; Abbasali Dadashi Roudbari
Abstract
Climate change is a key factor in most weather-related disasters worldwide. Regarding its distinctive geographical location and diverse climate, Iran has the most variable climate in the world. The present study aims to investigate the effectiveness of the MPI-ESM-LR model from the CMIP5 model series ...
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Climate change is a key factor in most weather-related disasters worldwide. Regarding its distinctive geographical location and diverse climate, Iran has the most variable climate in the world. The present study aims to investigate the effectiveness of the MPI-ESM-LR model from the CMIP5 model series in predicting the monthly temperature of Iran under representative concentration pathway scenarios (RCPs) with the CORDEX-WAS project. In this research, for the historical period of 1980-2005, the daily air temperature data of 49 synoptic stations of the country and the MPI-ESM-LR model under the CORDEX project were used. Likewise, for the future period, from the predicted temperature data of RCP 8.5, RCP 4.5, and RCP 2.6 scenarios of the mentioned model in three periods of the near-future (2021-2050), mid-future (2051-2075) and far-future (2076-2100) was used. Validation of the model was done with three statistical indices: r, RMSE, and MBE. The results revealed that the model has a good performance. The slope of the temperature trend in station data and model data has been increasing in the historical period and the future period in RCP8.5 and RCP4.5 in all months, the temperature trend slope has been observed in every decade. In all months, the maximum anomaly of temperature under the scenarios studied in all three future periods can be seen in the northwest and western highlands. The eastern and southeastern regions of Iran have indicated minimum temperature anomalies, except in RCP 2.6 and RCP 8.5, respectively, the southern coasts and the northeastern heights of the country also show minimum temperature anomalies. In the cold half of the year, the minimum area of temperature anomaly has been extended to the north-western heights and low-altitude interior regions of the country.
Climatology
khadijeh javan; mohammadreza Azizzadeh
Abstract
The outputs of general circulation models (GCMs) usually have a bias compared to observational data, and some corrections must be made before using them to develop future climate scenarios. The bias correction methods are the standard statistical methods for processing the output of climate models. In ...
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The outputs of general circulation models (GCMs) usually have a bias compared to observational data, and some corrections must be made before using them to develop future climate scenarios. The bias correction methods are the standard statistical methods for processing the output of climate models. In this research, the effect of five bias correction methods on the projected precipitation of the GFDL-ESM4 model in the Lake Urmia basin has been evaluated. The methods used in this research include linear scaling (LS), local intensity scaling (LOCI), power transformation (PT), distribution mapping (DM) and delta change factor (DC). Statistical metrics such as the correlation coefficient, root mean square error (RMSE) and percentage bias (PBias) have been used to evaluate the accuracy of the corrected data in the period of 1990-2014 compared to the observational data and to choose the best method for correcting the data of future scenarios. research results showed that the delta change method significantly improved the raw estimates after correction; Therefore, this method was used to correct the data of scenarios SSP1-2.6, SSP2-4.5 and SSP5-8.5. In addition, the projection of the mean annual precipitation shows a decrease between 2 and 9 percent in SSP1-2.6, between 5 and 17 percent in SSP2-4.5, and between 8 and 26 percent in SSP2-8.5 compared to the observed data.
Climatology
Atefeh Hoseini Sadr; bromand salahi; Gholam Hasan Mohammadi
Abstract
The aim of this study is to investigate the long-term fluctuations and trend in horizontal visibility in the northwest of Iran. For this purpose, hourly horizontal visibility data from 7 synoptic stations were used for the period of 1951-2020. The Koschmieder approach was used to calculate the extinction ...
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The aim of this study is to investigate the long-term fluctuations and trend in horizontal visibility in the northwest of Iran. For this purpose, hourly horizontal visibility data from 7 synoptic stations were used for the period of 1951-2020. The Koschmieder approach was used to calculate the extinction coefficient. Moreover, the Mann-Kendall and Rdit tests were applied to examine the trend of horizontal visibility. Also, the percentages of very good visibility (>19 km) compared with bad (<10 km) visibilities. Based on the results the annual average of horizontal visibility in northwest of Iran is ~13 km. This study showed three different fluctuation periods in the regional average of horizontal visibility: the first period (1951-1985) showed a sharp decrease in the visibility, the second period (1987-2005) was characterized by a low and stable visibility, and the third period showed a recent relative improvement. The regional average of horizontal visibility (extinction coefficient) exhibited a significant decreasing (increasing) trend of -0.167(0.0017) km per year at a confidence level of 0.01. The significant decreasing trend was confirmed in all stations except for the Ardabil station. The most severe decreasing trend was detected in Sanandaj and Zanjan stations with rates of 0.183 and 0.179 km year-1, respectively. The region-average of Rdit statistic in northwest Iran in the early 1950s was ~0.85, but it decreased to around 0.3 in the 1990s. Despite the recent improvement in horizontal visibility, reaching the reference distribution (i.e. Rdit=~0.5), the decreasing trend of horizontal visibility was still confirmed. The percentage of trend analysis of very good and bad visibility showed an increase in bad visibilities (from 5% to 25%) and a decrease in very good visibilities (from 80% to 5%), which confirms the decreasing trend in horizontal visibility. Hazy condition with 38.7% was the most influential weather phenomenon in visibility degradation.
Climatology
Hassan Zareh; Saeed Movahedi; Dariush Rahimi
Abstract
Reduction in productivity of horticultural and agricultural products, increase in pests, reduction in quality of agricultural products, and threat to food security are the consequences of climate change. The impact of climate change on agriculture leads to an increase in risk and risk-taking in the field ...
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Reduction in productivity of horticultural and agricultural products, increase in pests, reduction in quality of agricultural products, and threat to food security are the consequences of climate change. The impact of climate change on agriculture leads to an increase in risk and risk-taking in the field of agricultural activities. The results of the observational data review confirm the occurrence of climate change. The annual temperature anomaly of Bushehr province indicated an increase in the frequency of years with temperatures above the average from 1996 to 2021. According to the Pettitt's test, this increase is about 1.2 c˙. In addition, the significant increase in temperature at the 95% confidence level and Z values ≥ 2(in Mann-Kendall test) confirmed the occurrence of climate change in Bushehr province. The estimated data of the model for the future period confirm the continuation of the increasing trend of olive temperature thresholds for the period (2014-2040). The findings of the research indicated that with the increase in temperature for at least the following 20 years, the olive tree's cooling needs will not be met and the flowering season will occur in March instead of April. In the future, more areas will have an annual temperature of more than 26 °C. Therefore, in the future, the olive growing period will increase from 90 days to 150 days. With the increase in the number of days with temperatures above 40°C, the fruit burns more and the quality of olives decreases. Therefore, in addition to Asalouye and Dashtestan counties (1994-2019), Kangan, Jam, Deir and Dashti counties, the northern foothills of the province, and parts of Dilam (2017-2040) are added to the unsuitable olive areas. The favorable areas for olive cultivation will be moved to the west of the province.
Climatology
Yagob Dinpashoh; Saeid Jahanbakhsh-Asl; Asma Azadeh Garebagh
Abstract
In this study the values of potential reference crop evapotranspiration were calculated using the FAO-56 Penman Monteith method in six stations located in southern shores of Caspian Sea. Trends in annual ET0 values of the stations were analyzed using the Mann-Kendall test. Then to determine the relative ...
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In this study the values of potential reference crop evapotranspiration were calculated using the FAO-56 Penman Monteith method in six stations located in southern shores of Caspian Sea. Trends in annual ET0 values of the stations were analyzed using the Mann-Kendall test. Then to determine the relative importance of climatic variables on ET0 in a certain station factor analysis conducted. To do this, correlation matrix (R) of seven variables also called similarity matrix was constructed. The significance of correlation coefficients were tested. Results of trends in ET0 showed that in all the stations (except Noshahr) trends of annual ET0 were upward and significant. The slopes of trend lines were positive in all the stations. Factor analysis showed that the first two factors accounted the total variance in the range of 56.5 per cent in the Rasht to 79.6 per cent in the Sari. The largest loading of the first factor is attributed to sunshine hours in the station Rasht, however, it was maximum air temperature in all other sites. In the case of the second factor, the largest loading belonged to wind speed (in Rasht, Gorgan, Sari and Noshahr) and precipitation (in Ramsar and Astara). The findings of this study can be helpful in optimum management of regional water resources.
Climatology
Roghayeh Maleki Meresht; Bromand Salahi; Mahnaz Saber
Abstract
The current research was carried out to analyze the changes in precipitation in northwest Iran during the coming decades based on GCM models. For this purpose, first, the precipitation of 1985-2014 was trended based on the Mann-Kendall test. Then, the daily precipitation data for each of the studied ...
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The current research was carried out to analyze the changes in precipitation in northwest Iran during the coming decades based on GCM models. For this purpose, first, the precipitation of 1985-2014 was trended based on the Mann-Kendall test. Then, the daily precipitation data for each of the studied stations was simulated in SDSM6.1 software for 1985-2014. Then, under the scenarios (SSP2-4.5) and (SSP5-8.5) of CanEsm5 and MPI-ESMI-2HR models, the precipitation of 2015-2043 was predicted. To evaluate the performance of CMIP6 models and compare the basic and predicted values, MSE, RMSE, and MAE statistical measures were used. According to the results of the Man-Kendal test, the precipitation of the base period in the stations of Tabriz, Ardabil, Urmia, Takab, and Maragheh has a decreasing trend and in the stations of Meshginshahr, Sardasht, Mako, Khalkhal, Sarab, Jolfa, and Parsabad it has an increasing trend. Among the 12 investigated stations, only the Maragheh station had a significant decreasing trend. In other stations, precipitation trends were not significant. According to the predictions made based on the mentioned models, under the medium scenario (SSP 2-4.5), the precipitation will decrease in late winter and early spring. In other months, especially summer and autumn months, the percentage of precipitation will be higher. Based on the SSP5-8.5 scenario, the highest percentage of precipitation decrease in the MPI model was predicted by 33% in Jolfa, Sardasht, and Maragheh stations, and in the CanESM5 model, about 33-35% in Jolfa, Takab, and Urmia stations. According to the results, although both models predicted precipitation with a relatively high error, the MPI model had a lower error and more accuracy in predicting precipitation than the CanESM5 model.
Climatology
Hashem Rostamzadeh; Saied Jahanbakhsh asl; Mir kamel Hosseini; Mohammad Omidfar
Abstract
AbstractChanges in the incidental behaviors are among the most important aspects of global climate change with significant consequences on human society and the environment. Monitoring and measuring heavy rainfall events are important for understanding the nature of severe weather fundamentals and future ...
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AbstractChanges in the incidental behaviors are among the most important aspects of global climate change with significant consequences on human society and the environment. Monitoring and measuring heavy rainfall events are important for understanding the nature of severe weather fundamentals and future assessment. In this study, Global Precipitation Measurement (GPM) experiments with ground station data were performed at 20 synoptic stations for intense daily detection (25 mm and above) of precipitation over an 8-year period (2021-2014). Statistics such as coefficient of determination (R2), correlation coefficient (R) and root mean square error (RMSE) were used to compare and evaluate the observational and satellite data. Comparison of the maps obtained from GPM satellites and ground stations showed that the spatial distribution of precipitation from two similar bases is the same and the low and high rainfall areas correspond to the region. GPM satellite detected precipitation zones well so that the spatial correlation coefficient between GPM satellite and observed was 0.81. The results of the ANOVA test between the observational data and the GPM satellites showed that due to the low significance level of p-value of 0.000, the assumption that the average precipitation is the same between the two databases is rejected. There is a significant relationship between the average precipitation at ground and satellite stations. Also, the results of Kolmogorov-Smirnov test showed that since the obtained p-value (0.819) is a number higher than the error value of the test (0.05), so the null hypothesis based on the equality of precipitation values recorded at ground stations and modeled are the same and the null hypothesis is confirmed.
Climatology
Ali Mohammad Khorshiddoust; saeed jahanbakhshasl; zahra abbasighasrik; fatemeh abbasighasrik
Abstract
Today, long-term forecasting of climate variables has received much attention in order to be aware of the extent of change and, consequently, to take the necessary measures to mitigate the adverse effects of climate change. In this study, minimum temperatures in Kurdistan province were predicted using ...
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Today, long-term forecasting of climate variables has received much attention in order to be aware of the extent of change and, consequently, to take the necessary measures to mitigate the adverse effects of climate change. In this study, minimum temperatures in Kurdistan province were predicted using LARS-WG6 downscaling for the next three 20-year periods (2040-2021, 2060-2041, 2080-2061). For this purpose, the HadGEM2-ES general circulation model and three scenarios of RCP8.5, RCP4.5 and RCP2.6 were used. To generate the time series of future periods, daily data for the statistical period 1989-2019 were used and the trend of its changes was analyzed using Mann-Kendall test. The results showed that LARS-WG6 software simulates the minimum values of the minimum temperature well with low error indicators. Also, based on the results of the HadGM2-ES global model output in the study area, the minimum temperature in the future period will be higher than the base period in all scenarios and periods. The intensity of this increase under the RCP8.5 scenario is related to the last period of the century (2080-2061) and its lesser extent is related to the period (2060-2041) under the RCP4.5 scenario. Examination of seasonal averages also shows that spring has a lower temperature increase and autumn has a higher temperature increase. The trend of changes shows that the trend is positive and negative in both directions, so that in most stations and scenarios in different forecast periods, spring will have the most positive trend and autumn will have the most negative trend. Therefore, it can be concluded that the temperature will increase in future periods and the effect of cold waves will decrease.
Climatology
Mojtaba Nassaji Zavareh; Hossein Hokmabadi; Alireza Asadolahi
Abstract
Late spring frost cause a lot of damage to the agricultural sector every year. Prediction of this phenomenon is needed to active protection of plants. In this research, using FAO experimental method, daily and hourly data of two meteorological stations were used to determine the coefficients of the experimental ...
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Late spring frost cause a lot of damage to the agricultural sector every year. Prediction of this phenomenon is needed to active protection of plants. In this research, using FAO experimental method, daily and hourly data of two meteorological stations were used to determine the coefficients of the experimental model for prediction radiation frost in Qazvin Plain. also, in order to investigate the climatic condition of spring frost, the daily minimum temperature data of Qazvin and Buinzahra stations were used. The analysis of sixty years data in Qazvin stations showed that the intensity of frost has decreased during these years, but frequency of frost in Ordibehesht month has increased. Air, dew-point at two hours after sunset and minimum temperature relate 25 events of radiation frost at Simorgh station were used for regional coefficient calculation based on two models. These models were evaluated using 14 events of radiation frost at Tat stations. The mean absolute error(MAE) for testing and evaluating of Model1 was 0.71℃ and 1.21℃ and for Model2 was 0.67℃ and 1.09℃. The findings also showed that both models have acceptable accuracy in estimating the minimum temperature of the next day. It is proposed that these two models can be used for prediction of radiation frost in other regions.
Climatology
Mehdi pourahmad; mostafa karampour; behroz nasiri
Abstract
The aim of this study was to reveal the relationship between land cover changes and changes in aerosol optical depth index in the Middle Zagros. In this regard, two categories of MODIS sensor remote sensing products were used. First, land cover changes in the study area were performed using MODIS sensor ...
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The aim of this study was to reveal the relationship between land cover changes and changes in aerosol optical depth index in the Middle Zagros. In this regard, two categories of MODIS sensor remote sensing products were used. First, land cover changes in the study area were performed using MODIS sensor land use classification derivative product. In the second part of the research, the trends of dust events were investigated based on the station data of the dust codes of 4 stations of Khorramabad, Shahrekord, Yasuj and Abadeh. In addition, the trend of Aerosol Optical Depth Index (AOD) was examined using MOD04-L2 Madis sensor product for the statistical period 2000 to 2020. The results showed that there were 6 layers of rangeland, forest, agricultural, urban, residential, barren and water areas in the Central Zagros, in which the forest floor has decreased by about 123 square kilometers per year. Rangeland cover, which is the main cover of the study area, has remained relatively stable, and agricultural land uses have increased significantly, from 7% in 2000 to 9.5% in 2020. Urban and residential lands had also increased. On the other hand, a review of the 21-year time series trend of the AOD index indicates an upward trend over the last 21 years. Among the land use classes, the two categories of pastures and forests, which in fact occupy more than 90% of the study area, have shown an inverse relationship with the AOD index. But the class of agricultural lands was directly related to the AOD index. Therefore, the decreasing trend of forest floor in the region has been significantly associated with the increasing trend of AOD in the region and on the other hand, the increasing trend of agricultural land has been associated with the increase of AOD in the region.
