| Full text | |
| Author(s): Show less - |
Machado, Luiz A. T.
;
Unfer, Gabriela R.
;
Brill, Sebastian
;
Hildmann, Stefanie
;
Poehlker, Christopher
;
Cheng, Yafang
;
Williams, Jonathan
;
Hartwig, Harder
;
Andreae, Meinrat O.
;
Artaxo, Paulo
;
Curtius, Joachim
;
Franco, Marco A.
;
Cecchini, Micael A.
;
Edtbauer, Achim
;
Hoffmann, Thorsten
;
Holanda, Bruna
;
Khadir, Theodore
;
Krejci, Radovan
;
Kremper, Leslie A.
;
Liu, Yunfan
;
Meller, Bruno B.
;
Poehlker, Mira L.
;
Quesada, Carlos A.
;
Ringsdorf, Akima
;
Riipinen, Ilona
;
Trumbore, Susan
;
Wolff, Stefan
;
Lelieveld, Jos
;
Poeschl, Ulrich
Total Authors: 29
|
| Document type: | Journal article |
| Source: | NATURE GEOSCIENCE; v. N/A, p. 11-pg., 2024-11-08. |
| Abstract | |
Atmospheric aerosol particles are essential for forming clouds and precipitation, thereby influencing Earth's energy budget, water cycle and climate on regional and global scales. However, the origin of aerosol particles over the Amazon rainforest during the wet season is poorly understood. Earlier studies showed new particle formation in the outflow of deep convective clouds and suggested a downward flux of aerosol particles during precipitation events. Here we use comprehensive aerosol, trace gas and meteorological data from the Amazon Tall Tower Observatory to show that rainfall regularly induces bursts of nanoparticles in the nucleation size range. This can be attributed to rain-related scavenging of larger particles and a corresponding reduction of the condensation sink, along with an ozone injection into the forest canopy, which could increase the oxidation of biogenic volatile organic compounds, especially terpenes, and enhance new particle formation. During and after rainfall, the nucleation particle concentrations directly above the canopy are greater than those higher up. This gradient persists throughout the wet season for the nucleation size range, indicating continuous particle formation within the canopy, a net upward flux of newly formed particles and a paradigm shift in understanding aerosol-cloud-precipitation interactions in the Amazon. Particle bursts provide a plausible explanation for the formation of cloud condensation nuclei, leading to the local formation of green-ocean clouds and precipitation. Our findings suggest that an interplay of a rain-related reduction in the condensation sink, primary emissions of gases, mainly terpenes, and particles from the forest canopy, and convective cloud processing determines the population of cloud condensation nuclei in pristine rainforest air. Rainfall induces nanoparticle bursts within the Amazon rainforest canopy by scavenging large particles and bringing down ozone-rich air, according to aerosol, trace gas and meteorology data from the Amazon Tall Tower Observatory. (AU) | |
| FAPESP's process: | 22/07974-0 - Synergistic effects of climate change and land use on carbon source and sink of Amazon forest ecosystem |
| Grantee: | Luiz Augusto Toledo Machado |
| Support Opportunities: | Research Program on Global Climate Change - Thematic Grants |
| FAPESP's process: | 17/17047-0 - Aerosol and clouds life cycles in Amazonia: biogenic emissions, biomass burning and impacts on ecosystem |
| Grantee: | Paulo Eduardo Artaxo Netto |
| Support Opportunities: | Research Program on Global Climate Change - Thematic Grants |