Solar Cycle Influence on Ionospheric Outflows and Implications for Geomagnetic Activity

Details Solar Cycle Influence on Ionospheric Outflows and Implications for Geomagnetic Activity Solar Cycle Influence on Ionospheric Outflows and Implications for Geomagnetic Activity

Dec 2011

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011agufmsm54b..03l&link_type=abstract

American Geophysical Union, Fall Meeting 2011, abstract #SM54B-03

Physics

[2427] Ionosphere / Ionosphere/Atmosphere Interactions, [2736] Magnetospheric Physics / Magnetosphere/Ionosphere Interactions, [2740] Magnetospheric Physics / Magnetospheric Configuration And Dynamics, [2784] Magnetospheric Physics / Solar Wind/Magnetosphere Interactions

Scientific paper

Global simulations have shown that the presence of ionospheric ions in the magnetosphere has a major influence on geospace dynamics including, among other effects, modifications of the ionospheric potential and currents, inflation of the magnetosphere, intensification of the ring current and development of sawtooth oscillations. The hemispheric fluence of ionospheric outflows changes during the solar cycle in two fundamental ways. First and most importantly for superthermal outflows, the fluence increases with geomagnetic activity, which itself exhibits complex solar cycle dependence. Thus enhanced geomagnetic activity induced by the stronger solar wind driving prevalent around solar maximum increases ion outflow and mass loading of the magnetosphere. Second and perhaps more importantly for thermal outflows, an increase in solar EUV flux at solar maximum causes the underlying thermosphere and ionosphere to expand. The result is an increase, on average, in both the dayside flux and the hemispheric fluence of ionospheric outflows, especially O+, at solar maximum. Aspects of these influences are demonstrated in global simulations. When outflows driven by Alfvénic Poynting fluxes flowing toward the ionosphere are included in the simulations, weak to moderate solar wind driving typical of solar minimum (e.g., as measured by the Vasyliunas et al. (1982) SW-M coupling parameter) tends to produce steady magnetospheric convection states and isolated substorms. Moderate to strong solar driving more typical of solar maximum tends to promote more intense substorms and sawtooth oscillations. It is difficult based on the current state-of-the-art global simulations that include the effects of ionospheric outflows to fully systematize the solar cycle dependence of the impacts of ionospheric outflows on magnetospheric dynamics because the effects of the outflow depend on its flux and bulk properties, e.g., composition, field-aligned velocity and thermal energy, and the distribution of all of these characteristics across the auroral and polar regions. Physical models capable of correctly regulating these properties remain a work in progress.

Affiliated with

Also associated with

No associations

Rating

Solar Cycle Influence on Ionospheric Outflows and Implications for Geomagnetic Activity does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Solar Cycle Influence on Ionospheric Outflows and Implications for Geomagnetic Activity, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Solar Cycle Influence on Ionospheric Outflows and Implications for Geomagnetic Activity will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1891931