By Dieter Bilitza
Young scientists from both Spain and the Czech Republic recently had multi-day visits to NSSDC. The purpose of these visits was to foster collaborations connected with the evolution of the International Reference Ionosphere (IRI). They were hosted by Dr. Dieter Bilitza, who chairs the IRI Working Group (a joint project of the Committee on Space Research, COSPAR, and the International Union of Radio Science, (URSI)). Dr. Manuel Hernandez-Pajares and Dr. Jaume Sanz from the Polytechnical University of Cadalonia (UPC) in Barcelona, Spain, visited NSSDC from September 21- 29, 2000. The UPC group has developed its own algorithms for deducing ionospheric total electron content (TEC) information from GPS data using the data provided by the International GPS System (IGS) data distribution. The goal of the collaboration with Dr. Bilitza is the use of GPS and TOPEX data to update IRI TEC predictions globally.
During the month of October, Dr. Bilitza hosted a visit by Dr. Vladimir Truhlik from the Institute of Atmospheric Physics of the Czech Academy of Sciences in Prague, Czech Republic. Dr. Truhlik is working on new models for the electron temperature and ion composition in IRI using a large volume of data from the Russian Cosmos and Interkosmos satellites. His models will be introduced as a new option for the electron temperature in the next version of the IRI model. During his visit he helped to implement the new option into the IRI code. He also studied some of the older ionospheric data sets at NSSDC and their potential for improvements of IRI. Another project involved the study of the light ion ratio (He+/H+) with data from the 1978-launched Japanese ISS-B spacecraft.