Analysis of Climatic Zoning of the Persian Gulf and Oman Sea Basins Based on the Koppen–Trewartha Classification Scheme with Climate Change Approach
Alireza
Shakiba
shahid Beheshti University
author
Mahmood
Raeini sarjaz
استاد گروه مهندسی کشاورزی-آب، دانشگاه علوم کشاورزی و منابع طبیعی ساری
author
Aliakbar
Matkan
دانشیار مرکز مطالعات سنجش از دور و GIS دانشگاه شهید بهشتی
author
Mohammad
Rahimi
دانشیار دانشکده کویرشناسی، دانشگاه سمنان
author
Ameneh
Dasht
همکار پژوهشی مرکز مطالعات سنجش از دور و GIS دانشگاه شهید بهشتی
author
Amin
Hoseini Asl
مربی مرکز مطالعات سنجش از دور و GIS دانشگاه شهید بهشتی
author
text
article
2020
per
Introduction Climate change due to human activities has the great potential to impact local climate zones. Which will change regional climate zones and reorganize global climate distribution. Under these conditions some zones decrease, some disappear and in some areas, new zones created. In general, two important issues in climate change studies are predicting the intensity and distribution of future climate change and estimating the magnitude and intensity of its potential impacts on Earth's ecosystems. Another important issue is to determine the effect of these changes on existing ecosystems of dryland zones at different spatial scales. Therefore, achieving a classification system that can help detect these changes is one of the challenges in climate change. A look at past studies in this area reveals that the classification scheme that can display both climate and vegetation characteristics in a single format has been used more than other classification schemes in climate change studies. Hence, in this study, the same approach used by researchers around the world as the Koppen–Trewartha classification system is used. Which take into account these two characteristics. This implemented as the most appropriate classification scheme for Iran in climate change and drought management studies in the current and future conditions of the country. In addition, this classification scheme allows for a more accurate representation of climatic ranges and sub-types. 2. Materials and methods In this research, climatic classification has been done by Koppen–Trewartha method in the Persian Gulf and Oman Sea. In this classification scheme, the global climate is into six major climatic groups. Five groups (A, C, D, E, F), based on temperature criteria, and sixth group (B), or dry group; are based on precipitation criteria. Climatic classification was by coupon travertine using network data. In order to select the appropriate network size, meteorological stations with 30-year data, which correspond to the normal period of 1961- 1990, selected as validation criteria and their climatic type was based on recorded data, which were calculated by station data. Then the climatic type in the basin mapped based on the network data with different resolutions selected. Based on the geographical coordinates of the stations, their type extracted at each resolution and analyzed with the type obtained from the station data and the best fit was the criterion for the results of both data sources (station and network data). Validation of data with 14 synoptic stations in the study area revealed. The scaled data covers 5 minutes, 74% for the networks, and 87% for the 2.5 minutes and 30 seconds. Finally, in order to perform climatic grouping based on network data, median temperature and 2.5 min spatial resolution data in the 2000 baseline period and 2030s, 2050s and 2080s for the four RCP 2.6, RCP 4.5 scenarios, RCP 6, RCP 8.5 From the climatology centers, the data matrix was created for Iran. Precipitation and temperature ratios of each month calculated from the total annual precipitation for each matrix cell over the time interval under study by ARC MAP software then they extracted based on mean precipitation and mean temperature data generated by programming in Matlab software of their climatic type. Subsequently, the climatic zoning plotted in the mentioned periods in the basin of the Persian Gulf and the Oman Sea. 3. Results and discussion The results showed 9 climatic zones including warm dry (Bwh), semi-arid (Bsh), semi-arid cold (Bsk), subtropical with dry summer (Csa), warm continental temperate (Dcsa), cold dry temperate (Dcsb), warm dry temperate with winter precipitation (Dcwa), cold dry temperate with summer precipitation (Dcwb) and warm temperate oceanic temperate (Doa) are present in the Persian Gulf basin and Oman sea. The dominant climatic zone in the warm and semi-arid basins is warm. These two zones cover 62 percent of the area, including the east, center and downstream of the western basin. After that, the climate is temperate at 23%. In this climate, the warm temperate oceanic temperate zones accounted for 9 and 7 percent, respectively. According to the average GCM models, the dry climate type (Bsh) and the semi-arid climate (Bwh) in the most optimistic scenario (RCP 2.6) account for approximately 62% of the Persian Gulf and Oman Sea Basin and in the worst-case scenario, (RCP 8.5) 89% will reach by the end of the 21st century. Simulations also show that temperate climatic types will largely disappear or will be very small and approximately 1% wide and will be scattered across the northwest basins of the study area. The subtropical climate zone also covers about 10% of the area. This zone will be mainly confined to the top of the basins. The results are consistent with research conducted globally such as Rubel et al. (2010), Beck et al. (2018), Tapiador et al. (2018), Barredo et al. (2019), in Algeria, Zeroual et al. (2019). Simulations of research in arid and semiarid regions show that these zones will increase in the future and a significant percentage of temperate zones will decrease. 4. Conclusion In this paper, climate classification in the Persian Gulf and Oman Sea basin has been adapted to present and future climate change approaches. In this regard, using the network data, the Koppen–Trewartha classification method has been implemented throughout this basin. Among the existing climate classifications, this method as one of the best methods provides a more accurate representation of climate ranges and its subtypes based on precipitation and temperature boundaries, and more than other classification schemes used in climate change studies. The results show a significant increase in the area of arid and semi-arid climate classes and consequently a decrease in the temperate climate class in the future relative to Basic Climate Period. Accordingly, in this basin, under the RCP 8.5 scenario as the maximum scenario, by the end of the 21st century, nearly 52 percent of the basin will be in arid climate. In addition, the area of temperate warm and cold climate, which covers more than 23% of the basin during the basic climate period, is reduced to 1% by the end of the century under RCP 2.6, RCP 4.5, RCP 6 and RCP 8.5 scenarios. It can be stated that the changes in climate zones are influenced by the interannual fluctuation response of temperature and precipitation elements to climate change and global warming.
Journal of Climate Research
https://www.irimo.ir/
2228-5040
1398
v.
40
no.
2020
1
11
https://clima.irimo.ir/article_113828_d66936808dbe9a648851274bb06e2436.pdf
An Analysis of Rainfall Changes in Iran
reza
doostan
استادیار اقلیم شناسی، گروه جغرافیا، دانشکده ادبیات و علوم انسانی- دانشگاه فردوسی مشهد
author
text
article
2020
per
1. Introduction: Fluctuation and change are the inherent characteristic of air and phenomena related to the atmosphere. This anomaly in the air in the long term or in the prevailing climate (climate), becomes the norm pattern. So the climate does not change in the short and fast, unlike air, But it is possible in the long term and under the influence of natural processes. Today, the behavior of climatic components such as temperature, precipitation, etc. has changed and their anomalies have increased over the past few decades. Researchers have described these anomalies in climate as anthropogenic climate change. They have revealed that misconduct has negatively impacted the Earth's system for the past several centuries, in particular causing system pollution and global warming. Atmospheric models predict an increase in the Earth's temperature and subsequently anomalies in different climates (IPCC, 2007). Therefore, climate of Iranian plateau is fragile to fluctuations of heat and dry periods or cold and humid periods in south of temperate climatic region and northern region of subtropical. Because in the arid and semi-arid climate of Iran, precipitations has been of particular interest in the past and the methods of obtaining water are their genius (qanat). On the other hand, the rainfall in these areas is irregular in time and location (Alijani, 2017), because where alluvial plains are located, Lack of water and water resources, and elsewhere, water is abundant in the northern and west of Iran mountainous regions. In other words, where there is water there is no land and where there is no water there is land. (Velayati, 2019). On the other hand, time of rainfalls with growing time does not match and most of the precipitation falls in the cold half of the year. Now has the behavior of these types of precipitation changed in the long term, and is it consistent with the prediction of anthropogenic climate change (IPCC) that precipitation anomalies is matches? 2. Data and methods:to this end, daily rainfall data from 33 synoptic stations (fig 1) in Iran over the past 60 years from 1959 to 2018 were studied. Precipitation values of one millimeter and more were introduced as precipitation days and were extracted at each station separately for 6 decades (10 years) to investigate changes in precipitation in Iran. Indicators is for changes in precipitation, including number of days of precipitation (Rd), number of days of severe rainfall (Rd> 0.95), maximum rainfall (RR Maximum) and amount of precipitation (mm) per year and decades (10 years) at each station in the study period. So each index calculated based on differences and changes with the last decade and changes of decades(trend or fluctuation) was determined at each station, In the next step, the spatial averages for the whole of Iran were calculated for 6 decades and the changes in each index were determined for Iran. Also, in order to investigate changes in the whole of Iran, the average annual time series of the above indices were determined during the study period. These series show the behavior of these indicators over the past 60 years in Iran. 3. Results and discussion: 3.1. decades changes of precipitation in station: As Figure (2) shows, Except for the 1970s, most of the regions in Iran had increased rainfall days compared to the previous decade, In the last 4 decades, most of Iran's stations have had a decrease in precipitation, And in the 2000s, all stations except Tehran, Khoy, and Ramsar, the other 30 stations in Iran, experienced a decrease in rainfall over the previous decade. Most precipitation falls are in western, southwestern and northern stations of Iran such as Rasht and Gorgan. Also precipitation in the station of Zahedan, and Yazd in of Iran's southern and central regions has decreased. On the other hand, the number of days of heavy rainfall increased in the four decades ending 2010 (Figure 3), but the decade of 2010 was recorded in most regions of Iran with days of heavy rainfall. In the 90s, most of the heavy rainfall was experienced at Iranian stations and western stations of Iran had the highest rainfall. But in the 2010s, except for northwestern stations of Iran, Ramsar, Tehran and Kerman, other parts of Iran had less severe rainfall than in the previous decade (2000), and Most of the reduction was experienced by Shahrekord and Hamedan stations and Caspian stations including Rasht and Babolsar. Also, changes of the maximum daily precipitation amounts in Iran over the past 6 decades indicate (Figure 4), during the period of study, the maximum precipitation increased in all parts of Iran, especially in the 80s and 90s most of the stations in Iran maximum rainfall increase experienced. In the 2010s, some areas of Iran, including west and southwestern Iran and Babolsar station in northern Iran, recorded the highest rainfall decrease over the previous decade. On the other hand, changes in amount of precipitation over the study period showed (Figure 5), In the three decades leading up to the 2000s (70s, 80s and 90s), the amount of precipitation in most parts of Iran has increased compared to the previous decade, but in the last two decades, the amount of precipitation has decreased in most parts of Iran. As Sanandaj and Uremia stations in the last three decades and Yazd, Torbat Heydariyeh, Shiraz, Rasht, Sabzevar, Khorramabad, Birjand and Bandar Abbas have experienced decreasing trend in precipitation in the last two decades. The most decline in the last decade occurred at Babolsar and Tehran stations. 3.2. Decades changes of Rainfall in Iran: Generally, decades changes of precipitation indices in Iran show (Table 1), the number of rainy days in Iran has been negative and during the whole study period(the last 60 years) there has been decreased an average of 7 rainy days in Iran. On the other hand, the days associated with heavy rainfall increased during this period except 2010, and the number of days of heavy rainfall in Iran increased by 3 days in the whole period studied. The maximum precipitation amount in Iran during the study period is increasing and positive trend, as the entire period of study the places average 7 mm increased. In terms of the amount of precipitation, severe downward trend in the spatial averages of the index is also evident in recent decades, especially in the last two decades. But throughout the period, given the increase in precipitation in the 1970s and 1980s, the average spatial value of this index across Iran indicates a 15 mm increase. Table 1: Decadal spatial variations of precipitation indices in Iran change 2010 2000 1990 1980 1970 1960 decade index -7 37 39 43 45 45 43 average Rain day -2 -4 -2 -1 2 - change +3 21 27 26 23 20 19 average Extreme rain day -6 1 4 2 2 - change +7 34 34 33 31 28 27 average Rain maximum 0 1 2 3 1 - change +15 318 329 342 340 316 302 average Rain amount -12 -12 1 24 14 - change 3.3. Iran Rainfall Time Series: The time series of rainfall characteristics over the past 60 years shows (Figure 6), The number of rainy days in Iran is decreasing, As before the 90s, the average rainfall in Iran was between 40 and 60 days per year and after that decade the average rainfall in recent decades reaches 30 days per year (graph a). So the rainfall in Iran has declined between 10 and 20 days in the long term. While days of heavy rainfall in Iran show a significant positive trend (graph b), and an average of 60 days of rain in the first decades of the study period to an average of 80 days has changed in recent decades. In this regard, the amount of annual maximum precipitation in Iran during the study period has a significant positive trend (graph d). Therefore, the average of maximum precipitation has increased over the past 60 years and has increased from at least 20-30 mm prior to the 1990s to more than 35 mm after this decade. Thus, during the period of maximum precipitation has increased. On the other hand, the amount of precipitation in Iran fluctuated during the period under study, not the directional change (graph c), and has moved from a minimum of 250 mm to a maximum of 420 mm around the average, Therefore, on average 330 mm of rainfall per year is averaged over 1 mm in Iran. So the amount of precipitation in Iran has not changed in the past 60 years. 4. Conclusion: Rainfall in Iran has changed and is abnormal to predict climate models and increase precipitation anomalies. This change is evident both on a decade scale and in time series, as the number of rainy days has decreased in most parts of Iran for the past 4 decades, this trend is more obvious in the west and southwest of Iran. While the amount of rainfall in Iran has not changed over the past six decades (the last 60 years), the average of 320 mm of precipitation from days with precipitation of 1 mm or more is almost constant. But Iran extreme rainfall days have significant increase. That is, the average annual precipitation is on a station that has already been created with 30 days of rain, today, with 20 days of rainfall, the same amount of rain falls, which should naturally be severe. This is also confirmed by the increasing trend of maximum rainfall amount in Iran. But given the variations in topography and the position of the stations on the Iranian plateau, the change in precipitation indices in all locations over the past 60 years has not been uniform; rather, the spatial heterogeneity of the indices is evident over time, that indicate the diversity of Iran's rainfall climate.
Journal of Climate Research
https://www.irimo.ir/
2228-5040
1398
v.
40
no.
2020
13
25
https://clima.irimo.ir/article_113829_938f30977599dc28f739368117b323dc.pdf
Statistical and synoptic analysis of heavy rainfall in south and southwest of Iran
Kamal
Omidvar
Prof. Yazd University
author
Nesa
Sepandar
Ph.D, Student, Yazd University
author
Gholamali
Mozafari
Associate Prof. Yazd University
author
Ahmad
Mazidi
Associate Prof. Yazd University
author
text
article
2020
per
Extended abstract Natural disasters have always occupied the human mind, and in spite of the increasing progress of human knowledge, human beings are always weak against these disasters. Floods are one of these disasters. Identifying floods is one of the most important steps in controlling it, and in this direction, data and their analysis can play a very decisive role. The first factor in causing floods is the intensity of rainfall, and the largest floods are related to heavy rainfall with a maximum instantaneous peak that occurs at a certain point in time. Heavy rainfall have the potential to be considered a threat in most parts of the world, as we have seen floods and the death of many people around the world by floods. Precipitation is the main atmospheric phenomenon resulting from the complex interactions of the climate system and has a complex behavior due to the connection with different components of the climate system. The occurrence of precipitation requires several conditions. Moisture availability, deep instability availability and cooling are necessary conditions for precipitation to occur. For heavy cloud precipitation to occur, these conditions must emerge at their strongest. Various definitions have been proposed for heavy rainfall in the world: criteria such as events greater than 50 or 100 mm or a probability of occurrence of less than 10, 20 and 25% have been introduced Existing studies based on hydrological statistics and flood events show that the southern and southwestern regions of Iran are among the most flood-prone parts of the country. In this study, heavy and pervasive rainfall in the southern and southwestern regions of Iran in the period 1986 to 2015 is statistically and synoptically examin. so, daily rainfall data from 17 selected synoptic stations in south and southwestern Iran during 1986–2015 were used. The dataset is also used by the National Center for Environmental Prediction / National Center for Atmospheric Research (NCEP / NCAR) with a spatial resolution of 2.5 x 2.5 in latitude and longitude. The variables used are geopotential data, sea level pressure maps (SLPs) specific humidity (q), zonal and meridians components of wind (u, v). We use the basic percentile index to determine the days associated with heavy rainfall and to separate them. The base percentile index is the most common method for calculating and determining severe and limit precipitation. It is mainly used to determine the number of days with high, very severe and extreme rainfall, specific percentile thresholds. According to international agreement, the total number of rainy days, days above or equal to the 99th or 95th percentile are considered as severe and limiting precipitation, respectively. In this study, the 95th percentile index is used. Considering the occurrence of events in 50% of the stations studied, heavy and pervasive precipitation events are separated. The average of 30-year rainfall (1986-2015) in the study area (southwest and south of Iran) shows that the northern regions of the study area have more average rainfall than other areas such as Koohrang, Shahrekord, Abadeh, Dogonbadan stations are located in this part and the lowest rainfall is allocated to the southeast and northwest corners of the study area, which includes very low altitude areas (including Abadan, Ahvaz, Bandar Lengeh, Bandar Abbas, Kish and Minab stations. Central regions such as Fasa and Shiraz have moderate rainfall. After separating the heavy rainfall events, we studied one day as a synoptically sampled event. Statistical analysis of the data shows that during the period under study, in 1991 and among the stations, Koohrang station had the most days with heavy rainfall. In synoptic studies, we have two types of approaches: circular to environmental and peripheral to circular. Classification and environmental approach to rotation are used in the study of precipitation because the temporal and spatial variations of precipitation are severe and the environmental method of rotation allows the researcher to focus on precipitation and consequently the synoptic patterns that are intended to be studied. Has. After identifying heavy rainfall events in the study area, a typical event was identified in the south and southwest of Iran. The heavy rainfall event on December 25, 2004 is significant in terms of intensity and prevalence. On December 25 and 26, 2004, 455 mm of rain fall reported from selected stations in southern and southwestern Iran in one day. The highest amount of rainfall is related to Yasuj station with 91 mm. analysis of synoptic maps showed that The strength of Sudan's low-pressure system provides the basis for instability and precipitation on heavy rainy days that affect the study area. At 850 hPa, southwestern currents combine the humidity of the Arabian Sea, Oman, the Gulf of Aden, and part of the humidity of East Africa and send it from the Red Sea along the southwest-northeast axis to the study area. also pressure gradient between The high pressure of Europe and the low pressure of Sudan creates instability and cyclonic conditions in the region. These conditions absorb moisture from moisture sources such as the Red Sea and the Arabian Sea and send it to the study area. At 500 hPa, on the eastern part of the Arctic shore, there is a turbulence from the eastern Red Sea to the Caspian Sea, which causes low pressures of 1000 hPa to rise to high altitudes. The high humidity seen on the map this day has caused heavy rainfall. On this day, subtropical jet stream is located next to the tropics at a speed of 65 meters per second in the west-east direction on Iran. With the relocation of the polar front to low latitudes and the displacement of the tropical side to the east, the amount of precipitation increases significantly.
Journal of Climate Research
https://www.irimo.ir/
2228-5040
1398
v.
40
no.
2020
27
40
https://clima.irimo.ir/article_113831_389e83668e80e8ec4ab897438e2be25d.pdf
Social and Economic Consequences of Climate Change (Case Study: Drought and famines of the Qajar period)
Zohreh
Shirinbakhsh
دکترای تاریخ ایران، پژوهشگر بنیاد ایران شناسی
author
text
article
2020
per
Abstract Iran’s geographic characteristics as a semiarid country which threatened by water deficit, is always as an important and effective factor in terms of power relations and economic- social evolutions. natural disasters ,including drought is one of the significant factors in historical evolutions, which is not noticeable in historical researches Accidently, because of concentration on political history in historical studies. In the coming research try to focus on this neglected topic in historical studies, according to refrences. This article is mainly concentrated of drought’s economic and social consequences and how much qajar society involved with this issue. To attain this question, this article rely on descriptive and analytical method and librarial data. Findings showes that, in iran at qajar period, there were numerous climate change like drought which resulted to expensive famines, weakening of economic foundation, including society livehood situation and broad rebellions.
Journal of Climate Research
https://www.irimo.ir/
2228-5040
1398
v.
40
no.
2020
41
47
https://clima.irimo.ir/article_113833_b63445a3c0b4cb2868f0b0a571808693.pdf
Investigation of Meteorological factors affecting dust Resiliency over Middle East Region
Saviz
Sehat
Assistant Prof. ASMERC
author
Mehdi
Rahnama
Assistant Prof. ASMERC
author
Sara
Karami
Assistant Prof. ASMERC
author
Abbas
Ranjbar
Associate Prof. ASMERC
author
Sahar
Tajbakhsh
Assistant Prof. ASMERC
author
text
article
2020
per
Dust phenomenon as one of the natural pollutants affected by climate change, has been considered as an environmental challenge in the Middle East region in recent years which its impact with heavy costs in social, economic and health areas considered as a serious threat to the sustainable development of countries. In this study during the years 2009 to 2018, by evaluating dust behavior as a matter of frequency, duration, intensity as well as spatial and temporal variation of dust events using dust storm index, visibility, aerosol optical depth accompanied with identification of climatological parameters by considering vegetation condition index over the Middle East, a more considerable clarification of dust sources over this region has been obtained.This study can pave the way for better dust readiness and resiliency as one of the extreme natural hazards affected by climate extremes.
Journal of Climate Research
https://www.irimo.ir/
2228-5040
1398
v.
40
no.
2020
49
59
https://clima.irimo.ir/article_113834_c7835bf1de684fecfe6ed3547ceb11e4.pdf
Whether climate change is an opportunity or a threat?
Evaluation of Potential Climate Change on Tropical Trees of Iran, Case Study: Palm Dates
Javad
Azizzadeh
دانشجوی کارشناسی ارشد اقلیم شناسی کاربردی، گروه اقلیم شناسی، دانشکده جغرافیاو علوم محیطی، دانشگاه حکیم سبزواری
author
Hamzeh
Ahmadi
دانش آموخته دکتری اقلیم شناسی کشاورزی، گروه اقلیم شناسی، دانشکده جغرافیاو علوم محیطی، دانشگاه حکیم سبزواری
author
Mohammad
Baaghideh
دانشیار اقلیم شناسی، گروه اقلیم شناسی، دانشکده جغرافیاو علوم محیطی، دانشگاه حکیم سبزواری
author
Alireza
Entezari
دانشیار اقلیم شناسی، گروه اقلیم شناسی، دانشکده جغرافیاو علوم محیطی، دانشگاه حکیم سبزواری
author
text
article
2020
per
Introuction Climate is one of the most important factors in human history and less agricultural activity that does not deal with one or more meteorological factors during the day. This is due to the important role climate that plays in human life, especially agricultural production. Climate plays a key role in the growth and production of crops and its changes directly affect the planting and cultivation of crops. Since the last two decades of the 20th century, the issue of climate change has become one of the most important challenges for mankind. Concerns about the decline in crop yields and food security are among the issues that have raised the issue worldwide. Long-term forecasts of climate change have been considered by various experts to inform the extent of the changes and thus take the necessary measures to mitigate the adverse effects of climate change. In general, the present study seeks to answer this research question; could climate change be a threat or an opportunity under the conditions of future climate change, and the effects on date palm? Matrial and Methods The present study seeks to answer the question of whether climate change can be an opportunity or threat for tropical trees. In this regard, at first, the date palm cultivation areas in Iran was determined based on climatic data. The long-term trend of palm cultivation areas was then evaluated based on effective agro-climatic indices. Then, based on the CMIP5 models at MarksimGCM database, based on the two radiative forcing RCP8.5 and RCP4.5, the projection of future climate conditions was compared with the baseline period. Results The results showed that based on the analysis of effective climatic parameters, there was a significant increasing trend in the area of palm cultivation in Iran. This incremental trend is important for temperature components such as minimum and maximum temperatures, hot days, and thermal accumulation in the palm tree's biological and vegetative thresholds. Based on the projected data and the increase in air temperature in the adjacent areas of date palm and higher latitudes in the central plateau of Iran showed that in these areas the thermal potential in terms of minimum temperature, maximum temperature and thermal accumulation for growth and development in the palm tree's biological and vegetative thresholds. Therefore, climate change for the palm tropical tree in higher latitudes and adjacent areas in the inner and eastern parts of Iran provides the opportunity for growth. Therefore, desert areas in the interior of Iran have the potential of climatic conditions for palm tree cultivation. It is important to change the strategic plans to develop this valuable product in these areas. Discussion In general, the results of the present study showed that: With the increase of air temperature and higher thermal accumulation in high latitudes and adjacent areas and similar to the palm cultivation zones in Iran, in fact new zones of central zones, climatic conditions and temperature potential for cultivation are needed. The palm will enjoy. Conclusion The results showed that according to the observation data of date palm cultivation areas in the baseline period (1985-2015), there is a significant increasing trend in effective climatic parameters. Evaluation of thermal accumulation at the palm biomass and vegetative thresholds showed that there was an increasing trend in the long-term thermal accumulation series at the baseline period. Evaluation of effective climatic parameters (minimum and maximum temperature and thermal accumulation in date palm biomass and vegetation) based on projected data in adjacent regions and higher latitudes in the central Iranian plateau showed that in these areas, the thermal potential in terms of minimum temperature, maximum and there is the potential for heat to grow in the palm tree's biomass. Therefore, climate change for the palm tropical tree in higher latitudes and adjacent areas in the inner and eastern parts of Iran provides the opportunity for growth.
Journal of Climate Research
https://www.irimo.ir/
2228-5040
1398
v.
40
no.
2020
61
80
https://clima.irimo.ir/article_113835_8dbda451f6beddd2329161fb5407e08e.pdf
Dust Storm Climatology in Sistan and Baluchestan Province over a 30-year period (1987-2016)
Noshin
Khodam
دانشجوی دکتری، هواشناسی، پژوهشگاه هواشناسی، تهران، ایران
author
Sahar
Tajbakhsh
استادیار، پژوهشگاه هواشناسی، تهران، ایران
author
Abasali
Beydokhti
استاد، مؤسسه ژئوفیزیک، دانشگاه تهران، تهران، ایران
author
Saviz
Sehat
استادیار، پژوهشگاه هواشناسی، تهران، ایران
author
Abbas
Ranjbar
دانشیار، پژوهشگاه هواشناسی، تهران، ایران
author
text
article
2020
per
This paper investigates the climatological changes of summer dust storm events over 30 years (1987 -2016) in Sistan and Baluchestan province in the southeast of Iran and their relation to large scale atmospheric circulation. The Dust Storm Index (DSI) was calculated for the five selected meteorological stations in Sistan and Baluchestan province. Moreover, the Indian Monsoon Index, as a large-scale atmospheric circulation in the summer and the Caspian-Hindu Kush index were calculated using the re-analyzed data from the National Center for Environmental Prediction and Atmospheric Research (NCEP / NCAR) with a horizontal resolution of 2.5 degrees. The results showed that during the mentioned period, the Indian monsoon experienced a significant decrease, while the Caspian-Hindu Kush index showed a significant upward trend indicating an increase of the sea level pressure difference between the Caspian Sea and the Hindu Kush Mountains, resulting in strengthening the north-south pressure gradient and wind speeds on the eastern borders of Iran and western Afghanistan. However, the dust storm index over the past15 years has declined significantly. In the next step, the correlation coefficients of the Indian Monsoon Index and the Caspian-Hindu Kush index were calculated by the Pearson method. Regarding the increase in the Caspian-Hindu Kush index, temperature has increased, while relative humidity has decreased in the most stations of the province. Surveys showed that in the summer of 1988 when the lowest amount of the Caspian-Hindu Kush index was calculated, the frequency of dust events at the Zabol station was lower than the long-term average, but the Indian monsoon occurred at intensity greater than the 30-year average., While in 2001, the highest incidence of dust storms was recorded in Sistan and Baluchistan province, especially in Zabol station. This year, both the Indian Monsoon Index and the Caspian-Hindu Kush index were higher than the long-term average, leading to dust genesis by strengthening northern currents and reducing relative humidity in this year.
Journal of Climate Research
https://www.irimo.ir/
2228-5040
1398
v.
40
no.
2020
81
89
https://clima.irimo.ir/article_113836_0583969c86691d4aee3aad74d1c88c26.pdf
Spatial modeling of the incidence of lamprey skin disease in Iran based on climatic data
Fatemeh
Alibeigi
دانشجوی کارشناسی ارشد مرکز مطالعات سنجش از دور و GIS، دانشکده علوم زمین، دانشگاه شهید بهشتی
author
A
SHAKIBA
دانشیار مرکز مطالعات سنجش از دور و GIS، دانشکده علوم زمین، دانشگاه شهید بهشتی
author
BABAK
MIRBAGHERI
استادیار مرکز مطالعات سنجش از دور و GIS، دانشکده علوم زمین، دانشگاه شهید بهشتی
author
Ali Akbar
Matkan
استاد مرکز مطالعات سنجش از دور و GIS، دانشکده علوم زمین، دانشگاه شهید بهشتی
author
text
article
2020
per
a
Journal of Climate Research
https://www.irimo.ir/
2228-5040
1398
v.
40
no.
2020
91
97
https://clima.irimo.ir/article_113839_ada708382c2372d20e4adb951402dac0.pdf