Co-rotating interaction region

(Abbreviated CIR.)

A term used in space weather to denote a compression region ahead of a coronal hole high-speed stream (CH HSS). They form due to the interaction of slower, ambient solar wind ahead of the higher-speed stream. They are not associated with every CH HSS; however, they most often develop ahead of the more persistent coronal holes. They usually result in particle density enhancement and interplanetary magnetic field strength increases and can cause geomagnetic storms when reaching Earth.

Space Weather Prediction Center, 2018: Coronal holes. Accessed 13 August 2018. Available at https://www.swpc.noaa.gov/phenomena/coronal-holes.

Space Weather Prediction Center, 2018: Solar wind. Accessed 13 August 2018. Available at https://www.swpc.noaa.gov/phenomena/solar-wind.

Term edited 13 August 2018.

An aggregation of sufficiently many atoms or molecules that it can be assigned macroscopic properties such as volume, density, pressure, and temperature.

The solid, liquid, and gaseous parts of the planet taken as a whole.

See numerical weather prediction, climate prediction;