2017 Workshop: Ionosphere and thermosphere storm

The ionosphere and thermosphere variations during geomagnetically active periods are mainly driven by energy and momentum dissipation from the magnetosphere and solar wind at high latitudes. The two major categories of interplanetary solar winds that are geoeffective are Interplanetary Coronal Mass Ejections (ICME) and Corotating Interaction Regions (CIR). ICME and CIR have distinct characteristics. ICMEs usually have a larger steady southward Bz component, whereas CIRs have highly variable Bz which fluctuates rapidly between north and south and lasts for several days. The commonality and difference in CIR- and ICME-induced thermospheric and ionospheric variations, such as their global structure, the disturbance propagation timing, and recovery, are still an open question. It is still interesting and challenging to understand how the thermosphere and ionosphere respond to the impulsive and strong driving from ICMEs and the weak or moderate, but almost constant energy dissipation for a long period of time during CIR events. We welcome presentations of both observations and numerical simulations of the storm-time changes of the thermosphere and ionosphere during ICME, CIR, and ICME+CIR storm events and the recovery of the thermosphere and ionosphere after these storms. Our session is interested in particularly recent storm events where coordinated observational campaigns have been conducted to characterize some of the key ionosphere/thermosphere parameters (such as electric fields, neutral winds and composition). These include, but not limited to, March 31-April 4, 2014; Sept 24-29, 2014; March 13-18, 2015; Sept 28-29; 2016 (all CIR storms); and March 17-19; 2013/2015 (St Patrick’ Days), and Oct 13-14, 2016 (ICME storms).