Sources of Anomalous Latitude Structure in Thermospheric Temperature and Density

The latitude structure of solar radiation deposited into the thermosphere ionosphere system is initially dependent almost entirely on the local solar zenith angle. Some of the energy does directly into heating the neutral gas, but a large fraction is initially stored as ionization, dissociation, and chemical energy, or as photoelectrons, which subsequently undergo a cascade of physical processes. Plasma created by the ionization is tied to the magnetic field, but can be transported away from the original source location by winds and electric fields, and release the stored energy at another place and time. Photoelectrons can be transported even to the opposite hemisphere before deposited their energy. Dissociation energy can take days or weeks to finally release the stored energy in three-body recombination in the dense lower thermosphere. The range of physical processes can conspire to produce apparently anomalous latitude structure in neutral temperature and density. A new global ionosphere plasmasphere model, based on the Field-Line Interhemispheric Plasma (FLIP) model, has been used to describe the actual heating rates. FLIP contains all the appropriate photo-chemistry, and photoelectron production and transport.