The formation of CIRs at stream-stream interfaces and resultant geomagnetic activity [chapter]

I. G. Richardson
2006 Recurrent Magnetic Storms: Corotating Solar Wind Streams  
Corotating interaction regions (CIRs) are regions of compressed plasma formed at the leading edges of corotating high-speed solar wind streams originating in coronal holes as they interact with the preceding slow solar wind. Although particularly prominent features of the solar wind during the declining and minimum phases of the 11-year solar cycle, they may also be present at times of higher solar activity. We describe how CIRs are formed, and their geomagnetic effects, which principally
more » ... h principally result from brief southward interplanetary magnetic field excursions associated with Alfv6n waves. Seasonal and long-term variations in these effects are briefly discussed. 2018-07-20T04:05:42+00:00Z
doi:10.1029/167gm06 fatcat:kpv2ebdvjnhudpvo4z7o7mgyte