Height-integrated Pedersen conductivity in both E and F regions from COSMIC observations

Altitudinal distribution of Joule heating is very important to the thermosphere and ionosphere, which is roughly proportional to the Pedersen conductance at high latitudes. Based on the Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) satellites observations from 2008 to 2011, the height-integrated Pedersen conductivities in both E (100-150 km) and F (150-600 km) regions and their ratio γP (∑PE/∑PF) have been calculated. The result shows that the maximum ratio in the northern summer hemisphere is ~5.5, which is smaller than that from the Thermosphere-Ionosphere-Electrodynamics General Circulation Model (TIE-GCM v1.94) simulation (~9). This indicates that the energy inputs into the F region may be underestimated in the model. The seasonal variations of the ratio have been investigated for both hemispheres, and an interhemispheric asymmetry has been identified. The variational trend of the ratio is similar in both hemispheres, which reaches minimum at local summer and maximum at local winter. However, the difference of the ratio from local summer to local winter in the southern hemisphere is larger than that in the northern hemisphere.