Impact winter

An impact winter is a period of global cooling caused when an impact injects sunlight-blocking material into the atmosphere. Its severity depends on how much material reaches the atmosphere and how long it remains there.

Impact ejecta: Material blasted from a target by an impact, ranging from vapor and dust to large fragments. Fine ejecta can spread through the atmosphere and reduce incoming sunlight.
Chicxulub impactor: The asteroid or comet whose impact formed the Chicxulub crater about 66 million years ago. Its collision is linked to abrupt darkness and cooling at the Cretaceous–Paleogene boundary.
Luis Walter Alvarez: An American physicist who shared the 1968 Nobel Prize in Physics for work on particle physics. His team's impact explanation for the boundary iridium anomaly prompted debate about global catastrophe.
Photosynthetically active radiation: The 400–700 nanometer portion of sunlight used by plants and other photosynthetic organisms. Atmospheric darkness sharply reduces the light available for photosynthesis.
Climate modeling: The use of mathematical representations and computing to simulate Earth's climate system. Models estimate how ejecta properties translate into global temperature and darkness.
Stratospheric aerosol: Suspended liquid or solid particles in the stratosphere that scatter or absorb radiation. Long-lived aerosols can cool the surface by reflecting sunlight.
Cretaceous–Paleogene extinction event: A mass extinction about 66 million years ago that eliminated roughly three-quarters of species, including non-avian dinosaurs. Impact-driven darkness and cooling are leading explanations for the extinction's rapid ecological collapse.
Walter Alvarez: An American geologist who helped identify the asteroid impact hypothesis for the Cretaceous–Paleogene extinction. His geological work with Luis Alvarez connected boundary-layer evidence to a catastrophic impact.
Primary productivity: The rate at which organisms produce organic matter from inorganic sources, chiefly through photosynthesis. A collapse in sunlight can reduce food production at the base of ecosystems.
Atmospheric residence time: The average time a substance remains in the atmosphere before removal or transformation. The persistence of impact dust and aerosols sets the duration of sunlight reduction.

Linked from 15 pages