However, if forests and vegetation are unhealthy, they can be a good breeding ground for fires, making them uncontrollable and causing major damage.

• Particulate Matter (PM), whose size varies according to the nature of the fire
• Carbon dioxide (CO2), a greenhouse gas contributing to global warming
• Carbon monoxide (CO), a gaseous pollutant emitted during incomplete combustion processes, toxic because it can reduce the blood's capacity to transport oxygen
• Nitrogen oxides such as NOX (NO, NO2), which contribute to the production of ozone (O3) in the troposphere.
• Ozone, which is toxic to vegetation and human health

To distinguish fire years from non-fire years, we looked at Fire Radiative Power data, which tells us about fire intensity in terms of energy released. This variable is measured by instruments from space, such as the MODIS instrument onboard the Aqua satellite. MODIS passes over the same spot twice a day, at 01:30 local time (p.m. and a.m.). 

CO - important because it is mainly emitted to the atmosphere during incomplete combustion processes linked to anthropogenic activities and biomass burning. CO in LA is from power generation, which accounts for a dominant 97.20% of CO emissions. This indicates that the energy sector's combustion processes are the primary source of CO pollution in the region.

The daily CO total column time series seen by TROPOMI and calculated within a 10km zone around the city of Los Angeles show that 2020 has seen several periods of high CO concentrations (mid-August and mid-Spetember). 2019 is more representative of background concentrations, emitted from anthropogenic activities such as power generation or chemical processes.

Source:  Ambient-Air-Quality-Standards 

We use a case study to show the impact of the 2020 September wildfire on LA’s PM2.5 spatial pattern. The impact starts to rise rapidly around Sep 10, peak around Sep 14, and the enhancement largely decreases around Sep 19.

Our result shows that the wildfires complexes happened in August and also in September in 2020 increase the concentration of CO and PM2.5 in LA which is already a densely populated area. The excessive high values of CO and PM2.5 coming from the wildfires can significantly affect human lives, health specially children and older population.