from Part III - Spatial and Temporal Variations of the Geomagnetic Field
Published online by Cambridge University Press: 25 October 2019
The ionosphere boundary between the magnetosphere and atmosphere is often considered thin in the magnetosphere-ionosphere-thermosphere system. This approximation is not valid at the inner boundary, where height variation is important in ionosphere-thermosphere (I-T) coupling, particularly with respect to momentum/energy transfer. Here the Cowling channel and energy coupling between regions are better modelled including altitude variations. In the equatorial region the equatorial plasma fountain results from a field perpendicular ExB drift and field aligned plasma diffusion, while the equatorial ionisation anomaly is formed by removal of equatorial plasma by upward ExB drift. Under magnetic storm conditions an eastward prompt penetration electric field and neutral winds contribute. The polar cap ionosphere and auroral zones transfer solar wind energy into the magnetosphere. In the polar cap key indicators for energy/momentum transfer to the solar wind I-T system are the cross-polar cap potential/electric field, and the relationship to the interplanetary magnetic field where linear and non-linear relationships may occur. Models have been produced to describe various aspects of the coupled system. In the auroral zones aurora are associated with different regions and processes; substorm-associated aurora, shock associated aurora, pulsation aurora, cusp aurora and mid-latitude aurora. These categories and recent models are referenced.
To save this book to your Kindle, first ensure no-reply@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Find out more about the Kindle Personal Document Service.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Dropbox.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Google Drive.