19 research outputs found
Substantial Increases in Eastern Amazon and Cerrado Biomass BurningāSourced Tropospheric Ozone
The decline in Amazonian deforestation rates and biomass burning activity (2001ā2012) has been shown to reduce air pollutant emissions (e.g., aerosols) and improve regional air quality. However, in the Cerrado region (savannah grasslands in northeastern Brazil), satellite observations reveal increases in fire activity and tropospheric column nitrogen dioxide (an ozone precursor) during the burning season (AugustāOctober, 2005ā2016), which have partially offset these air quality benefits. Simulations from a 3āD global chemistry transport model (CTM) capture this increase in NO2 with a surface increase of ~1 ppbv per decade. As there are limited longāterm observational tropospheric ozone records, we utilize the wellāevaluated CTM to investigate changes in ozone. Here, the CTM suggests that Cerrado region surface ozone is increasing by ~10 ppbv per decade. If left unmitigated, these positive fireāsourced ozone trends will substantially increase the regional health risks and impacts from expected future enhancements in South American biomass burning activity under climate change
Impact of the June 2018 Saddleworth Moor wildfires on air quality in northern England
The June 2018 Saddleworth Moor fires were some of the largest UK wildfires on record and lasted for approximately three weeks. They emitted large quantities of smoke, trace gases and aerosols which were transported downwind over the highly populated regions of Manchester and Liverpool. Surface observations of PM2.5 indicate that concentrations were 4ā5.5 times higher than the recent seasonal average. State-of-the-art satellite measurements of total column carbon monoxide (TCCO) from the TROPOMI instrument on the Sentinel 5āPrecursor (S5P) platform, coupled with measurements from a flight of the UK BAe-146ā301 research aircraft, are used to quantify the substantial enhancement in emitted trace gases. The aircraft measured plume enhancements with near-fire CO and PM2.5 concentrations >1500 ppbv and >125 Ī¼g mā3 (compared to ~100 ppbv and ~5 Ī¼g mā3 background concentrations). Downwind fire-plume ozone (O3) values were larger than the near-fire location, indicating O3 production with distance from source. The near-fire O3:CO ratio was (ĪO3/ĪCO) 0.001 ppbv/ppbv, increasing downwind to 0.060ā0.105 ppbv/ppbv, suggestive of O3 production enhancement downwind of the fires. Emission rates of CO and CO2 ranged between 1.07 (0.07ā4.69) kg sā1 and 13.7 (1.73ā50.1) kg sā1, respectively, similar to values expected from a medium sized power station