New Publication: Tree mortality in Amazonian floodplains

Recently we mentioned that drowned trees along the Uatumã River a likely the cause for enhanced methane emissions measured at ATTO. Now Angélica Resende and her co-authors investigated how changes in flooding regimes impact tree mortality in floodplains. They compared two sites in the Amazon basin. Along the Jaú River, the floodplain environment is still largely undisturbed. Along the Uatumã near ATTO, on the other hand, the flooding regime has been altered by the implementation of the Balbina hydroelectric plant further upstream.

Understanding nighttime methane emissions

Santiago Botía and his co-authors analyzed methane in the atmosphere at ATTO. Over the course of five years, they measured methane along with other properties, such as wind speed, wind direction and the stratification of the atmosphere. They noticed frequent pulses of methane emissions during the night, but only under certain conditions. Surprisingly, these nighttime events mostly occurred in the months of July to September – the dry season in the Amazon. Botía et al published the study Open Access in Atmospheric Chemistry and Physics, Issue 20: Understanding nighttime methane signals at the Amazon Tall Tower Observatory (ATTO).

Transport of black carbon-rich smoke from Africa to the Amazon

When forests burn those fires produce a lot of smoke. And that smoke usually contains soot, also called “black carbon”. Black carbon particles are aerosols that absorb radiation and as such can warm the Earth’s atmosphere and climate. But we still have much to learn about aerosols, their properties, and distribution in the atmosphere. One of those things is the question of how black carbon emitted from biomass burning in Africa (i.e. forests, grasslands, savannas etc.) is transported across the Atlantic and into the Amazon basin, and what role it plays there. Bruna Holanda and her co-authors tackled this in their new study published in ACP.

When do fungi release their spores?

Fungal spore emissions are an important contributor to biogenic aerosols, but we have yet to understand under what conditions fungi release their spores. Nina Löbs and co-authors developed a new technique to measure emissions from single organisms and tested this out at ATTO and with controlled lab experiments. They published their results in the Open Access Journal Atmospheric Measurement Techniques.