Precipitable water vapour (PWV) variations as observed using GPS during 2021 forest fires in Southwestern Turkey

Devastating forest fires occurred in the southwestern part of Turkey in summer 2021. Besides the fire itself, air quality standards also drastically dropped. Mugla and Antalya were affected the most by the forest fires. Also, precipitable water vapour (PWV) values show different behaviours from the climate typical. Precipitation, temperature, and pressure parameters were investigated, and no anomalies were found. Particulate matters and other pollutants resulting from forest fires were the remaining indicators behind the PWV fluctuations. The relation between PWV and particulate matters from 2.5 to 10 microns (PM10) was investigated at nine Global Positioning System (GPS) stations located at Antalya and Mugla using 15 air quality monitoring stations. The PWV analysis results show a sudden increase in PWV during the forest fires at most GPS stations. After the fires, PWV values decreased over time. However, PWV values were still higher than before the fires. Furthermore, the mean value, the maximum values, and the standard deviation of PM10 during and after the forest fires were investigated. Results show that the PM10 values were in line with the forest fires effects and correlated with the distance between air quality monitoring stations and the forest fire. Most air quality monitoring stations have higher maximum and average PM10 values during the forest fires than after the forest fires. The correlation coefficient between the two datasets shows a high correlation during the forest fires at all the GPS stations. Therefore, results indicate that, as the PM10 concentration increases, PWV values also increase.