The International Reference Ionosphere (IRI) is an international project sponsored by the Committee on Space Research (COSPAR) and the International Union of Radio Science (URSI). These organizations formed a Working Group (members) in the late sixties to produce an empirical standard model of the ionosphere, based on all available data sources (charter ). Several steadily improved editions of the model have been released. For given location, time and date, IRI describes the electron density, electron temperature, ion temperature, and ion composition in the altitude range from about 50 km to about 2000 km; and also the electron content. It provides monthly averages in the non-auroral ionosphere for magnetically quiet conditions. The major data sources are the worldwide network of ionosondes, the powerful incoherent scatter radars (Jicamarca, Arecibo, Millstone Hill, Malvern, St. Santin), the ISIS and Alouette topside sounders, and in situ instruments on several satellites and rockets. IRI is updated yearly during special IRI Workshops (e.g., during COSPAR general assembly). More information can be found in the workshop reports. Several extensions are planned, including models for the ion drift, description of the auroral and polar ionosphere, and consideration of magnetic storm effects.
An IRI Newsletter is published quarterly. Please contact the Newsletter editor K. Oyama if you would like to be included on the distribution list. There is also an electronic mailer with uptodate IRI-relevant information.
The IRI master copy is held at the National Space Science Data Center (NSSDC) and updated according to the decisions of the Working Group. The software package distributed by NSSDC includes the FORTRAN subroutines, model coefficients (CCIR and URSI), and documentation files. The IRI build-up and formulas described in detail in a 158-page NSSDC report (Bilitza, 1990).
* Fortran source code from NSSDC's NSSDC's anonymous FTP site
* PC Windows version from University of Mass. Lowell site
* Online computation and plotting through IRIweb
IRI-generated parameters and animations:
* Real-time IRI worldmaps and movies (last 24 hours) at MIT site
* IPS maps of real-time TEC for Autraliasia, North America, Europe, and Japan
* Computation of ionospheric conductivities using IRI90 and CIRA72 models at WDC Kyoto
* MPEG movies of global maps of IRI density and tmeperature at the Space Environments Branch of NASA Glenn Research Center
* Models page of LDEF Archive System at NASA Langley Research Center
* The SPace ENVironment Information System (SPENVIS) developed at the Belgian Institute for Space Aeronomy for ESA/ESTEC
* IRI TEC maps generated by a University of Leicester web site
NSSDC ID: MI-91J
References (some available online as PDF documents):
List of IRI-related issues of Advances in Space Research
K. Rawer, D. Bilitza, and S. Ramakrishnan, Goals and Status of the International Reference Ionosphere, Rev. Geophys., 16, 177-181, 1978.
K. Rawer, S. Ramakrishnan, and D. Bilitza, International Reference Ionosphere 1978, International Union of Radio Science, URSI Special Report, 75 pp., Bruxelles, Belgium, 1978.
K. Rawer, J. V. Lincoln, and R. O. Conkright, International Reference Ionosphere-IRI 79, World Data Center A for Solar-Terrestrial Physics, Report UAG-82, 245 pp., Boulder, Colorado, 1981.
K. Rawer and C. M. Minnis, Experience with and Proposed Improvements of the International Reference Ionosphere (IRI), World Data Center A for Solar-Terrestrial Physics, Report UAG-90, 235 pp., Boulder, Colorado, 1984.
D. Bilitza (ed.), International Reference Ionosphere 1990, NSSDC 90-22,
Greenbelt, Maryland, 1990.
[*** PDF: pages 0-84, pages 85-end ***]
D. Bilitza, K. Rawer, L. Bossy, and T. Gulyaeva, International Reference Ionosphere - Past, Present, Future, Adv. Space Res. 13, #3, 3-23, 1993.
D. Bilitza, International Reference Ionosphere - Status 1995/96, Adv. Space Res. 20, #9, 1751-1754, 1997.
D. Bilitza, International Reference Ionosphere 2000, Radio Science 36, #2, 261-275, 2001. [*** PDF ***]
NASA Official: Dr. Robert McGuire, Head of the Space Physics Data Facility