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Relative humidity is considered as one of the most important climatic parameters and atmospheric phenomena. The purpose of the present study is to evaluate the regional algorithms for estimating relative humidity using remote sensing data in Hormozgan province. In this regard, the products (MOD05 and MOD07) were used to for estimating the total perceptible water, air temperature and sea- level pressure. Also the product (MOD35) was used for cloud testing, which by performing this test, 2190 cloudless images with 95% confidence for processing was identified. To evaluate the results, radio sound data of Bandar Abbas and synoptic stations in all over the Hormozgan were used. The results showed high accuracy of the used algorithms and experimental model so that R2 and RMSE values of the recorded layers of the sensor and ground data were acceptable. They are in good agreement with ground station measurements. The results showed that the climate of the province is semi-desert with a long warm season and a short cool one. With a closer look, it was found that sea-level pressure and total perceptible water (TPW) in this province are highly correlated with the topography of the region, so that, maximum total perceptible water and sea level pressure were recorded in coastal lowland areas and minimum in the highlands of the province. According to zoning maps, Hormozgan province can be divided into four parts due to relative humidity: from very dry climate with less than 20% relative humidity which is recorded at the highlands to humid areas with more than 65% relative humidity at the coastal area.

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 Drought defined as a climatic phenomenon with the humidity and rainfall shortage as compared with normal conditions. This phenomenon affects on all of aspects of human activities‌, severely. while, studies associated with this phenomenon on the basis of appropriate methods are very low. In the  present study, effort  has been made to analyze the drought state in Ardabil province by means of software system capabilities in MATLAB and SEPI index in two temporal scales of 6 and 12 months. The climatic data of synoptically stations of Ardabil were used, Parsabad and khalkhal countian in Ardabil province. Results of study show that SEPI index reflects the features of two SPI and SEI indices well. And also enters temperature in the studying of drought conditions as one of the effective parameters in changing of drought intensity. There‌fore, the investigation into drought with SEPI index is better than SPI index. Studies associated to drought on the basis of SEPI index shows that drought process is increasing in Ardabil province. Temperature also has an increasing flow with higher intensity. Longest temporal continuation of drought in province, has occurred in Parsabad station in temporal scale of 12 months, from June‌, 1998 to November, 1999 in 18 month period. The greatest percentage of drought occurrence is in Parsabad station and the minimum of that is observed in Khalkhal station.

 


[1] - Akbar Goldust: PhD student's of climatology in environmental planning Mohaggeg  Ardabil University

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Early heat waves are extreme events that cause heavy losses in plant and animal life and cause many social and economic problems for communities. The purpose of this study was to identify synoptic patterns and statistical analysis of preterm heat waves in northwestern Iran. To do this, the maximum daily temperature data of March 14th was used for fourteen synoptic stations in the northwest of the country during the statistical period (1333-1393) Hijri Shamsi. Then, on the basis of the threshold, the Baldy index was selected for 61 days of heat wave. All statistical characteristics of the data were processed in SPSS software. They were The elevation data of the middle atmosphere of the atmosphere was extracted from a NCEP / NCAR database on a network with an arc 2/5 × 2/5 degree on the 0 to 70 degree eastern longitude and 0 to 60 degrees north latitude. The matrix was made up of 864 columns in 40 rows, with rows of days with thermal waves and elevation data on the columns on the middle of the atmosphere. The analysis of the basic components was performed on the algebraic data matrix matrix And 12 components that account for about 93 of the variations in pressure levels above 500 hp, were identified. To identify the coherent patterns, cluster analysis was performed on the scores of the components by the WARD integration method. Five types of pre-heat generation waveform patterns were identified. The results of this study showed that the premature heat waves in the northwest of Iran are due to high altitude formation in southern Arabia, the Aden valley and the center of Sudan at a level of 500 hpa and the formation of Sudan's low pressure in the sea level and the discharge of its tabs to the north and northeast of the region The case study (Northwest of Iran) also includes events occurring.

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Study of land use/cover changes is widely used in environmental planning. During the last decade, growing increase of aridity in Uromiyah Basin has become a major regional and even national problem. The purpose of this study is to reveal the changes in land use/cover in the southern and southeastern parts of the basin with using 2 images for month of July of 2000 to 2017. Landsat TM and OLI data and NDVI were used for classification this study. Land use/cover maps in the two studied years were provided using Maximum Likelihood Classifier (MLC) algorithm applied on two series data including spectral bands (data series 1) also spectral bands and filter texture layer (data series 2) and six categories of land use/cover containing Irrigated Farmland, Dry Farmland, garden, rangeland, bare land and water bodies were distinguished.. The accuracy of the produced maps were assessed and compared with the training samples derived from Google Earth images and Kappa Index, overral accuracy, producer accuracy and user accuracy. The results demonstrated that the maps produced using the data series 1 have higher accuracy and the overall accuracy of the maps of 2000 and 2017 using the data series 2 are 98.93 and 98.29 and these values for data series 1 were gained 99.28 and 91.45, respectively. In additional, texture filtering decreased amount of mixing between classes of rangeland, Irrigated Farmland and garden. The results of change detection showed considerable increase in the area of Irrigated Farmland (13.44) and garden 1.85 (27.24) an also at the studied period, the area of the water bodies and rangeland were decreased to 1.58 and 22.94%.
 

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In this study, the prediction of precipitation and temperature values using the general atmospheric circulation models during 1964-2005 is investigated. Climatic data including daily values of total precipitation and mean temperature were obtained from the Iranian Meteorological Organization. Considering the climate change scenarios RCP4.5, RCP2.6 and RCP8.5 for the coming period 2010-2100 were evaluated under the canESM2 climate change model of Aharchai Basin. Due to the low accuracy of the general circulation models, the SDSM4.2 miniaturization model was used and the changes in precipitation and mean temperature parameters were simulated for future time periods. In this study, to calibrate the SDSM model, among the 26 large scale climate parameters (NCEP), on average, 3 parameters have the highest correlation with the mean temperature and 5 parameters have the highest correlation with the average precipitation in the Aharchai Basin. The results of climatic parameters prediction showed that simulation of climatic parameters mean temperature was performed with higher accuracy than mean precipitation values. The reason is that the precipitation data are not normal and unconditional. The results show that the basin temperature averaged more during the period 2070-2099 under the scenario RCP8.5 than the observations period of 1964-2005 and the basin precipitation during the period 2070-2099 under the scenario RCP2.6 showed the highest increase in the entire study period.

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Today, fine dust and dust storms have become one of the important issues and problems of Iran and other regions of the world. This study is conducted to identify synoptic patterns of the dust storms in Ardabil Province (Iran) and monitor the origin and pathway of its places. The studied period is 34 years (1979-2013). The data used in this work are from synoptic stations of Ardabil province and the NASA’s upper atmosphere database. To achieve the goals of the study, the Environment to Circulation, Hierarchical Clustering Methods, and HYSPLIT model were used. According to the results, three patterns of geopotential height at 500 hPa levels were identified. Pattern No. 1 and 2 are almost similar to each other and represent the occurrence of a deep trough that formed from Central Europe and extended to the middle of the Red Sea. Based on these patterns, the study area is located in the East of this trough. The third pattern represents the occurrence of cut-of-low pressure blocking over the Black Sea and adjacent areas and placement of Ardabil province in the East trough of the formed blocking. The origin of dust in patterns 1 and 2 is the Eastern regions of Iraq and West of Iran while in pattern 3 is at 500 hPa level of the central areas of Iraq and at pressure levels of 850 and 1000 hPa of the central regions of Syria.
Keywords: Dust storm, Pattern extraction, synoptic analyses, HYSPLIT model, Ardabil province