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The conceptual modeling of the influences of ENSO by three mechanisms of atmospheric bridge dynamics on the atmospheric general circulation and the Middle East climate (anomaly of 500 hPa height level and sea level pressure on adjacent parts and areas). A East–west synoptic profile (top) and north–south profile from a Western perspective (bottom), The curves on the figure show the general fluctuation of the geopotential height and air pressure in the warm phase of ENSO (in contrast to the cold phase). In fact, the mass distribution of the atmosphere changes such as the pendulum or seesaw in the pattern of the mean of the Eastern and Western Hemispheres, especially in the winter of the Northern Hemisphere and the ENSO event (using the mean pressure difference of the Western and Eastern Hemispheres, which is not shown). B Eurasian synoptic, profile (STJ subtropical jet stream, PFJ polar front jet stream; + ζ represents positive vorticity advection of the head or input of STJ; blue and red triangles and semicircle refer to cold and warm fronts, respectively). Latin letters also simplify the sequence and path of all three mechanisms. C The satellite image on March 31, 2019 (www.ncdc.noaa.gov/gibbs/html/MSG-1/IR)
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In many parts of the world, teleconnection patterns are one of the climate phenomena that significantly change the causative climate anomalies, especially temperature and precipitation. Thus, statistical analysis and modeling of their effects are of great importance in order to understand the fluctuations and climate variability in a region. In thi...
Citations
... Alizadeh-Choobari et al. (2018a, b) investigated the precipitation pattern in Iran and reported the effect of ENSO on seasonal rainfall in the winter and spring. Several studies also reported the effects of ENSO fluctuations on annual, seasonal, and monthly precipitation in Iran and nearby countries (Ahmadi et al. 2022;Kazemzadeh et al. 2022;Perdigón-Morales et al. 2019;Zhang et al. 2022). Another large-scale indicator that affects the region's climate is IOD. ...
Iran experienced increasing droughts in recent years. Since droughts have devastating effects on the economy and irreparable impacts on the environment, knowing the factors affecting droughts can effectively help their early warning and loss reduction. The present study used Palmer Drought Severity Index (sc-PDSI) and large-scale atmospheric indices (ENSO, IOD) to examine how various factors affected drought (precipitation, temperature, evapotranspiration, VPD, NDVI) in eight regions of Iran from 1981 to 2020. Results revealed that the northwest and southeast of Iran experienced longer duration and more severe droughts in the last 40 years. There is an increase in annual total precipitation and average daily temperature in all regions of Iran. The vegetation cover has changed slightly; however, its density has increased on the Caspian Sea shores due to increased rainfall. Correlation analysis revealed ENSO as Iran’s primary driver of droughts, while the IOD affects sc-PDSI only in the central plateau. Besides, the ENSO significantly affects the vegetation changes in Iran. General trends in precipitation, temperature, evapotranspiration, VPD, NDVI, and sc-PDSI indicate northwest Iran as most prone to drought.
... The study area is Iran in southwest Asia with 1,648,195 km 2 ; it is the second largest country in the Middle East. The study area is located in latitudinal coordinates between 25 and 39° N and longitudinal coordinates between 44 and 64° E (Ahmadi et al. 2022). The average annual precipitation of Iran is recorded by one-third of the average precipitation in the world (Salimi et al. 2018). ...
Drought is an intangible natural disaster that can occur in any climate. The present study assessed drought vulnerability in Iran based on fuzzy logic and hierarchical analysis and weighted averaging process. Then, the weight and map of different components and values of ORness, GIS-OWA method were used to prepare a set of drought vulnerability maps based on effective drought index (EDI).
The study of vulnerable classes in terms of adaptation capacity showed that the northern regions of the country enjoy the highest adaptation capacity. The lowest level of compatibility is related to the cities located in the south of Kerman province, west of Khorasan Razavi province, and Ilam province. As far as the exposure component is concerned, vulnerability extends across the country. Also, cities in the provinces of Sistan and Baluchestan and south of Kerman are in a very vulnerable category regarding the sensitivity component. In other words, according to the type of component, different regions of the country are in the vulnerable category. Also, according to all computational ORness results, drought risk in Sistan-Baluchestan, Kerman, and Khuzestan provinces are in very high vulnerability category. Also, the risk of drought in the western and eastern regions of the country is moderate and high, and only are the central and desert regions of the country and parts of the north-western regions of the country in a state of vulnerability and, accordingly, enjoy lower risk than other parts of the country.
