Particulate matter and carbon dioxide gas concentrations and their effects on meteorology: a case study using Benghazi City, Libya

The main aim of this work is to assess the spatiotemporal variation of particulate matter (PM1, PM2.5 and PM10) during the monitoring period from February 2023 to December 2023 and to determine the level concentration of CO2 in the atmosphere. The station that was used in this work named AirVisual Outdoor monitor; this station recorded the parameters every five minutes. The data obtained from these stations are air quality index (AQI), temperature, humidity, wind speed and wind direction. The results showed the air quality index (AQI) in February, May, October and November periods is classified as unhealthy for sensitive groups (level 3), People with heart or lung disease, older adults, and children are considered sensitive and therefore at greater risk, the rest of periods are classified as moderate air quality (level 2). The highest values of PM1 and PM2.5 were recorded in the February period while the highest value of PM10 was observed in the May period. According to the classification and source of air pollution, the atmosphere contained mixed particles (fine and coarse particles) during all periods. The February period was affected by anthropogenic pollution and the rest of the periods were affected by mixed to natural pollution (dust source). In general, Benghazi city is more affected by natural pollution than anthropogenic pollution. Most of the meteorological parameters were positively correlated with PMs, which reflect that an increase in meteorology is associated with an increase in PMs. The May period recorded the highest value of CO2 424 ppm, May period is usually the period in which each year the highest CO2 levels are recorded because the plants will close their stomata to prevent water evaporation and reduce photosynthesis efficiency. At this time, human activities become more and more frequent, which eventually leads to an increase in the concentration of CO2 in the atmosphere. Globally the CO2 concentration in May 2022 was recorded 421 ppm by the Mauna Loa Observatory in Hawaii. In May 2023 was recorded 424 ppm, an increase of about 3 ppm degrees from last year, this increase caused the new rise in global warming caused by human activities.