Analysis of the Effect of North Atlantic and Mediterranean Oscillation Teleconnection Patterns on Variations of Cloudiness during Winter Season in Iran
محمد
رضایی
دانشجوی دکتری آب و هواشناسی ماهوارهای، دانشگاه تربیت مدرس
author
یوسف
قویدل رحیمی
استادیار گروه جغرافیای طبیعی، دانشگاه تربیت مدرس
author
text
article
2016
per
Clouds are one of the most complex elements in the climate system which not only change the energy budget but also affect the temporal and spatial distribution of climate elements. Ffluctuations of pressure in distant oceans may lead to variations of climatic elements in Iran. This study aims at indicating the impact of North Atlantic and Mediterranean oscillation teleconnection patterns on variations of cloudiness during winter season in Iran.
in this study, initially for 53 points in Iran the monthly cloudiness reanalysis data from NCEP for a 35-year period (1979-2013) with a resolution of 1.86 degree was obtained. Thereafter, the correlation between cloud covering was calculated for December to March, with Mediterranean oscillation (1979-2000) and the North Atlantic Oscillation data (1979-2013). in the figure below gridded point is represented by a map.
Data of percent cloudiness in Iran figure 1) The distribution of gridded point for
The obtained results show that under the best of circumstances in northwestern of Iran, the highest correlation between Mediterranean and the North Atlantic Oscillation index with cloudiness is -0.62 and -0.59 for January and February, respectively. Also, in all of the winter months, there is a significant negative correlation between teleconnection patterns and cloudiness at least for one area of Iran. Effect of the teleconnection patterns on the cloudiness, in terms of spatial was more uniform compared to precipitation. As a result, in the negative phase, cloudiness was steadily increased at Iran but as shown in previous investigations and also current study this was less evident regarding the precipitation.
Researches in Earth Sciences
Shahid Beheshti University
2008-8299
7
v.
1
no.
2016
1
15
https://esrj.sbu.ac.ir/article_95812_263ba3893d414169222f142e04b551a2.pdf
Spatial and temporal variability of precipitation and wet-dry spells in southern areas of Caspian Sea
یدالله
یوسفی
دانشگاه مازندران
author
text
article
2016
per
This study surveyed variability in precipitation in the southern part of the Caspian Sea using 8 index. Daily precipitation data for 5 synoptic stations with period 1956-2014 is obtained from Iran Meteorological Organization. Derived Indices from precipitation are the largest number of consecutive dry days, mean duration of consecutive wet days, mean precipitation of wet spells, number of annual wet spells, annual precipitation, largest number of consecutive wet days, maximum precipitation and number of days with precipitation equal to or greater than 1 mm. Using of Mann–Kendall for all indexes showed that mean duration of consecutive wet days and number of days with precipitation equal to or greater than 1 mm have distinctive decreasing trend. Any station has not any trend in CDD index. Investigate of NCPI Tele-connection showed that this index is correlated with monthly precipitation days in southern areas of Caspian Sea. But this index is not correlated with largest number of consecutive wet days. Annual precipitation without significant changes with decrease in number and duration of precipitation days show that annual precipitation is falling on fewer days during a year in this region.
Researches in Earth Sciences
Shahid Beheshti University
2008-8299
7
v.
1
no.
2016
16
30
https://esrj.sbu.ac.ir/article_95849_de1aeb11b6511ca1e6f5bebafe0669ea.pdf
Modeling hydrological Ghouchak - Roodak catchment by using HMS - HEC model
محمد مهدی
حسین زاده
دانشگاد شهید بهشتی
author
سپیده
ایمنی
دانشگاه شهید بهشتی
author
text
article
2016
per
Catchment as a Hydrosystem that react toward inputing rain. This reaction shown in dimention of the flood hydrograph. In this study, first using a combination of maps, land use and soil hydrologic group in ARC GIS, map of curve number was obtained for basin then Using HEC- geoHMS extention basin model was prepared. Finally, for estimate the height of the runoff and study the status of flooding and hydrological of Ghouchak - Roodak watershed, HEC- HMS model was implemented. In order to validate the model, five incident rainfall - runoff extract from Roodak hydrographic station and after modeling, estimation flow rate were compared with observation flow rate. results model in connection with the performance of the model in runoff and flood peak is not acceptable. Because the difference between the observation and estimation peak flow is over twenty percent.
Researches in Earth Sciences
Shahid Beheshti University
2008-8299
7
v.
1
no.
2016
31
43
https://esrj.sbu.ac.ir/article_95865_aae0442ec526bec580b391996420421c.pdf
ناصر
شفیعی ثابت
استادیار گروه جغرافیای انسانی، دانشگاه شهید بهشتی
author
سمیه
یوسفی
دانشجوی دکتری جغرافیا و برنامهریزی روستایی، دانشگاه شهید بهشتی
author
text
article
2016
per
Researches in Earth Sciences
Shahid Beheshti University
2008-8299
7
v.
1
no.
2016
44
61
https://esrj.sbu.ac.ir/article_95873_98bbd39d53d3a3dc1d923a7da33b78f4.pdf
Estimation of the active Uplift rate using “precise leveling” in the Central Alborz Mountains, Northern Iran
احسان
صابری
دانشجو دکتری زمین شناسی گرایش تکتونیک دانشگاه تربیت مدرس
author
علی
یساقی
دانشگاه تربیت مدرس
author
سعید
معدنی پور
دانشگاه تربیت مدرس
author
یحیی
جمور
سازمان نقشه برداری کشور
author
text
article
2016
per
The Alborz Mountains in northern Iran is an active fold and thrust belt which extended from Caucasus Mountains in the west to Binalud and north Afghanestan Ranges in the East. Active faults related uplift have not been systematically investigated across the Alborz Mountains. Here, we use the precise leveling technique to analysis active uplift and subsidence related to major controlling faults across the central Alborz Mountains. Our data gathered through a line that is perpendicularly aligned to the central Alborz Mountains along the N-trending Karaj-Chalus road. The results represent that the major active uplift of the southern part of the central Alborz Mountains has been focused in the hangingwall of the North Tehran and Mosha Faults with the uplift rate of 17±0.6 mm/22Yrs and 18.1 ± 0.6 mm/22Yrs respectively. The very low value of active uplift just at the vicinity of fault zones represent their present day locking behavior and reflect their higher potential of earthquake occurrence in the south central Alborz Mountains. There is also abnormal anomalies of 118 mm/22Yrs subsidence recorded in the footwall of Kandevan Fault. We attributed this high amount of subsidence to karstic related depressions developed in Upper Eocene evaporates in the fault footwall. Regional comparison of the mean active uplift rate shows relatively higher amount of uplift in the southern flank of the central Alborz Mountains (10.4 ± 0.6 mm/Yrs.) with respect to its northern flank (6.3 ± 0.6 mm/Yrs.).
Researches in Earth Sciences
Shahid Beheshti University
2008-8299
7
v.
1
no.
2016
62
74
https://esrj.sbu.ac.ir/article_95883_85ac215b0acc9cb0e1c8d6d3b525395e.pdf
مریم
امین الرعایایی یمینی
دانشجوی دکتری پترولوژی، دانشگاه تهران
author
فرامرز
طوطی
استادیار، دانشکده زمین شناسی، دانشگاه تهران
author
جمشید
احمدیان
استادیار، دانشگاه پیام نور، تهران، ایران
author
text
article
2016
per
Researches in Earth Sciences
Shahid Beheshti University
2008-8299
7
v.
1
no.
2016
75
90
https://esrj.sbu.ac.ir/article_95893_91cc77bd7074dbc8740be636efe1484e.pdf
Petrology of the ultramafic-mafic intrusions in Masuleh area, Gilan province
مرتضی
خلعت بری جعفری
پژوهشکده علوم زمین، سازمان زمین شناسی کشور
author
text
article
2016
per
Three small ultramafic-mafic massifs, located in vicinity of the Chepol, Zodel and Gilvandarud villages, in Masuleh area, southwestern Fouman are studied in this paper. These massifs are olivine websterite, websterite, lherzolite, olivine gabbro, hornblende gabbro, gabbro in compositions, and are cut by micro-gabbro-diabase dikes, and quartz-monzodiorite, micro-granite dikes and veins. The crystallization trend of these rocks is olivine-plagioclase-clinopyroxene-ortopyroxene-hornblende-biotite, which is similar to crystallization trend in closed-magma chambers in mid-ocean ridges, however occurrence of heteradcumalate texture with hydrous minerals, such as hornblende and biotite, indicate their crystallization in an open-magma chamber similar to those in arc domains. The gabbroic rocks include harzhburgite microenclaves and garnet xenocrysts, suggesting a mantle origin for their magmas. In discriminating diagrams, most of the samples are tholeiitic and in tectonomagmatic diagrams plot in arc domains. The spider diagrams display enrichment of LREE relative to HFSE which makes them comparable to subduction related magmatism. It seems that the parental magmas are probably produced by partial melting of mantle wedge which were influenced by subduction components and mantle diapirs but are differentiated in shallow magma chambers. Regarding to small to intermediate scale of the studied massifs, lacking of high grade metamorphic rocks and serpentinites, presence of hydrous minerals, and clear relationship between ultramafic-mafic rocks, the massifs may be compared to the Alaskan orogenic massifs
Researches in Earth Sciences
Shahid Beheshti University
2008-8299
7
v.
1
no.
2016
91
108
https://esrj.sbu.ac.ir/article_95903_4b2ffb954557f51827e65d9f1ab7317b.pdf
Geochemistry, Ore mineralogy and hydrothermal alteration characteristics of Kuh-Pang volcanic copper deposit in Saveh, middle part of Urmia-Dokhtar subduction zone
شاهرخ
رجب پور
دانشگاه شهید بهشتی
author
text
article
2016
per
The Kuh-Pang copper deposit is located in ~38 km NE of Saveh, within Eocene to Oligo–Miocene volcanic facies and between the middle parts of Urmia-Dokhtar subduction zone. The most important lithologic units of this area are andesite, basaltic-andesite, tuff, fine grain lithic tuff, rhyodacite, rhyolitic volcanic breccia and aglomerate. The volcanic rocks have sub-alkaline affinity and are tectonically placed within the calc-alkaline to high-k calcalkaline series. The tectonic setting indicates that rocks in the area belong to continental volcanic arcs. The ore has a similar stratigraphic unit within the volcanic facies as is stratabound. Ore textures include vein-veinlet, open space filling, replacement and laminated. Ore mineral paragenesis includes pyrite, chalcopyrite, bornite, chalcocite, digenite, covellite, malachite, azurite, hematite and Fe oxide and hydroxide. Wall-rock alteration is dominated by silicification, and then kaolinitization, carbonatization, sericitization, epidotization and to a lesser extent, chloritization. The ore mineralization is predominantly accompanied by silicification and carbonatization. Textures of pyrite together with replaced pyrite by Cu-sulfides texture in porphyritic andesite unit indicated two stages for copper mineralization in this district. Comparison of characteristics of mineralization in Kuh-Pang copper deposit with different types of copper deposits including tectonic setting, geologic setting, type of host and associated rocks, geometry, texture and structure, mineralogy, copper mineral paragenesis and alteration shows that Kuh-Pang copper deposit are similar to volcanic manto-type copper deposits
Researches in Earth Sciences
Shahid Beheshti University
2008-8299
7
v.
1
no.
2016
109
128
https://esrj.sbu.ac.ir/article_95821_3045c694aae476f7a8fe538babb4f10e.pdf
اعظم
سلطان محمدی
دانشگاه شهید بهشتی
author
محمد
رهگشای
دانشگاه شهید بهشتی
author
text
article
2016
per
Researches in Earth Sciences
Shahid Beheshti University
2008-8299
7
v.
1
no.
2016
129
151
https://esrj.sbu.ac.ir/article_95830_afa2a8e16928e5d1a6f87b7fe3100e38.pdf