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Synoptic-dynamic analysis of winter cold waves in Iran
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Ali Shahbaee Kotenaee *   1, Hossein Asakereh1 |
| 1- Zanjan University |
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Abstract: (128 Views) |
One of the important climatic events that has a great impact on the life of living organisms is extreme temperature events. Cold days and cold waves are examples of extreme temperature events in which unusual minimum temperature values are observed. The creation of these temperature conditions is a function of complex synoptic and dynamic patterns, the identification of which can be useful in increasing awareness of how these conditions are formed and predicting similar situations and thus reducing possible damages. In this research, based on the concept of relative coldness in time and place, cold wave was defined as a condition in which the minimum temperature standard score is less than -1.2; continue for at least 3 days and cover more than 20% of the country's area. In order to meet the objectives of the present research, two environmental (minimum temperature) and atmospheric databases (sea level pressure, geopotential height, atmospheric temperature and orbital and meridional wind component) were used for the winters of 1339 to 1394. The results of examining the patterns showed that all the cold waves in the country were caused by the formation of a high-pressure pattern on the surface of the earth. The arrangement of the two high-pressure systems of Siberia and Azores have played a very important role in guiding the cold air of northern latitudes towards the country. The location of sub-arctic low pressure in the northern regions of Europe and Russia has also caused the cold polar air to move to more southern latitudes. Mid-atmosphere patterns have also had a significant impact on the creation and continuation of cold waves. In such a way that the most severe, widespread and continuous winter cold waves were formed when the barrier systems were established in Eastern Europe and their eastern flank was placed over Iran.
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| Keywords: synoptic analysis, cluster analysis, dynamic analysis, pervasive cold, Iran |
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Full-Text [PDF 2180 kb]
(9 Downloads)
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Type of Study: Research |
Subject:
Special
Received: 2023/02/12 | Accepted: 2024/08/15 | Published: 2025/04/14
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