Modeling and ground observations of the ionosphere related to the COSMIC project

Ground observations have been used to study the ionosphere by providing electron density profiles and TEC distribution. In this paper, the existing ground and space facilities related to constructing the Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) Project are reviewed. We show that these observations can be employed to validate results derived from COSMIC satellites. In addition, the NCAR TIEGCM model is introduced to simulate ionosphere TEC during year of the solar minimum. The observations and simulations present a clear signature of the equatorial anomaly, in which the TEC shows a minimum on the magnetic equator and a maximum on each side. Meanwhile, it is interesting to see that the value of TEC in June (Day 170) becomes weaker with the crests moving toward the geomagnetic equator.