Observations of formaldehyde from the GOME-2 instrument onboard Metop-B on 19-20 August 2019.
By Federico Fierli (EUMETSAT)
GOME-2 is capable of measuring the total amount of formaldehyde (HCHO) over a specific location. Nevertheless, since HCHO is concentrated close to the surface, due to its volatility and reactivity, these observations are indicators of the location and intensity of the sources.
HCHO is a precursor (e.g. serves as a basis for multiple reactions, including the production of tropospheric ozone), and due to its toxicity and volatility is considered harmful.
HCHO is produced both by synthesis and natural reactions involving organic compounds; among these a significant source is biomass burning.
Satellite data show the significant input to the atmosphere that is due to the Amazonian fires (Figure 1) and the spread of HCHO in a southwesterly direction, driven by the Continental Low Level Jet. This jet is a dominant feature during South America’s austral winter.
Carbon monoxide (CO), observed by the IASI instrument onboard Metop-A (Figure 2) on 20 August, is also produced by wildfires, among other sources. The image shows the CO plume produced by the fires, before moving down to the southern Atlantic Ocean.
Biomass burning as a source of formaldehyde, acetaldehyde, methanol, acetone, acetonitrile, and hydrogen cyanide (Goephysical Research Letters)