Patterning and Synoptic Analysis of Heat Waves in Ardabil Province

- Bromand Salahi ¹ (Department of Physical Geography, University of Mohaghegh Ardabili, Ardabil, Iran.)
mahnaz saber ² (Postdoctoral Researcher in Climatology, Department of Physical Geography, Faculty of Social Science, University of Mohaghegh Ardabili, Ardabil, Iran)
fatemeh vatanparast ghaleh jouq ³ (Ph.D. Student of Climatology, Department of Physical Geography, Faculty of Social Science, University of Mohaghegh Ardabili, Ardabil, Iran)

Submited date : 2023-12-10 accepted date : 2024-01-15

Keywords: Clustering, Synoptic Analysis, Ardabil province, Heat Waves,

Abstract :

This research was carried out to identify heat waves in Ardabil province and analyze their synoptic patterns using an environmental-to-circulation method. For this purpose, the average daily maximum temperature data of Ardabil, Parsabad, and Meshkinshahr synoptic stations were used in the statistical period of 1980-2020. The 95th percentile index was determined as a criterion for identifying a hot day, and its duration of at least 3 days was considered as the basis for defining a heat wave. Examining the trend of SLP, HGT, and Tmax of these waves showed that in the hottest days of heat waves, the trend of SLP is downward and the trend of HGT and Tmax is upward. Clustering of heat wave generation patterns based on reanalysis data of sea level pressure and geopotential height of 500 hectopascals using cluster analysis method and Ward's clustering method led to the identification of 5 clusters which were presented in two main groups. In the first pattern, low pressure at the sea level surface and high pressure in the mid-atmospheric level, and in the second pattern, the location of the studied area in the west of the pseudo-Omega blocking of western Russia at the level of 500 hectopascals were identified as synoptic factors of heat waves in Ardabil province. The common feature of both models is the high thickness of the atmosphere over the region on the days of this event