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Mid-level clouds at the top of a smoke layer overlie the lower stratocumulus deck below. Phot taken off the coast of Angola, September, 2016. Photo Credit: Paquita Zuidema, Ph.D. |
Scientific Frontline: Extended "At a Glance" Summary: African Smoke and Cloud Brightening
The Core Concept: Smoke from agricultural fires in Africa brightens marine clouds, but the same weather patterns that transport the smoke also thin and reduce cloud cover, offsetting the smoke's cooling effect.
Key Distinction/Mechanism: The aerosol effect of smoke makes clouds more reflective (brightening), which should produce a cooling effect by redirecting sunlight back into space. However, atmospheric conditions, specifically the weather patterns carrying the smoke from Angola over the southeast Atlantic, concurrently diminish the cloud deck, counteracting the expected cooling.
Major Frameworks/Components:
- Biomass-burning emissions from African agricultural fires.
- Aerosol-cloud interactions and their influence on cloud properties, sunlight, and temperatures.
- The southeast Atlantic's extensive stratocumulus cloud deck.
- Observations from the Department of Energy's LASIC field campaign and NASA's ORACLES aircraft campaign, combined with 20 years of reanalysis data (2003–2023).