View of the Thomas Fire smoke plume from the International Space Station. Photo by NASA.
Charcoal and soot are formed during wildfire and when these fire-derived products interact with water, some of it dissolves and enters aquatic systems. The soluble component of charcoal and soot is termed “dissolved black carbon”. The main goal of a study, recently published by Sasha Wagner and colleagues, was to investigate whether the deposition of ash from the Thomas Fire (California, USA) had a measurable effect on dissolved black carbon in coastal surface waters. Beneath the smoke plume, dissolved black carbon concentrations were higher than other areas sampled. They also found that when Thomas Fire ash was mixed with seawater, it leached a substantial amount of dissolved black carbon. The release of dissolved black carbon from ash was further enhanced when the experiment was carried out under natural sunlight. Using carbon isotopes, they tried to estimate inputs of dissolved black carbon from ash to Santa Barbara Channel surface waters during the Thomas Fire. However, ash dissolved black carbon contributions were too small for them to effectively track inputs using carbon isotopes. Given the unpredictable nature of wildfires, they are logistically challenging to study in real time. This work provides a first step toward understanding atmospheric inputs of dissolved black carbon to coastal ecosystems impacted directly by wildfire. This work is entitled “Investigating atmospheric inputs of dissolved black carbon to the Santa Barbara Channel during the Thomas Fire (California, USA)” and was published in the Journal of Geophysical Research: Biogeosciences.
