Investigation of synoptic patterns of fire occurrence in the forests of the western Alborz Mountains

Forest fire is considered as a natural disaster and major potential threat in many parts of the world. Due to the lack of a comprehensive study in terms of the synoptic conditions of the fire incident in the studied area, the present study was conducted in order to identify the predominant synoptic patterns of fire occurrence in the western Alborz Mountains. To this end, first, the days of fire were obtained from the Department of Natural Resources of Gilan Province and the product (MCD14) Modis sensor (2007-2020). In order to determine atmospheric synoptic patterns, atmospheric maps were obtained from the NCEP site on all fire days. Totally, 240 fires occurred. Among the months of the year, July, August, and December had the highest incidence of fires. Based on the fires that occurred, three predominant synoptic patterns had the highest frequency of fires, including (1) Saudi-African high pressure dominant in the hot and cold seasons of the year, with three forms of omega blocking (16.5%), ridge (24.8%), and intrusion (22.2%), in total with a frequency of 63.5%; (2) European Migrant high-pressure system intrusion dominant in the hot period of the year, with a frequency of 21.7%; and (3) subpolar low pressure, which is generally dominant during the cold period of the year and responsible for about 14.8% of the fires in the region. Therefore, the most common occurrence of natural fires in the region is due to the high-pressure influence of Arabia and Africa in the hot and cold periods of the year.