During the triennium 1996-1999, URSI Commission G has been active through its Working Groups and sponsored symposia and workshops. Early in the triennium a Commission G web site was established (/ursi/) to ease communication between the chair and the membership. The following Commission G Working Groups have been active:

G.1. Ionosonde Network Advisory Group (INAG)
Chair : R. Conkright (USA)
Vice-Chairs : P.J. Wilkinson (Australia) and J-C. Jodogne (Belgium)
INAG has maintained a constant membership of around 230. The main medium for contacting INAG members remains the Bulletin. During the last three years one Bulletin (INAG-62) was produced. In addition, INAG produced a Proceedings, containing 24 papers, from the Session G5 at Lille General Assembly titled "Computer Aided Processing of Ionograms and Ionosonde Records". Copies of this report, reference number UAG-105, are still available from Ray Conkright, NGDC, STP, E/GC2, 325 Broadway, Boulder, Colorado 80303, USA. Copies of past Bulletins and the two proceedings are also available from Dr Phil Wilkinson, IPS, PO Box 1386, Haymarket NSW 1240, Australia. Work commenced on the INAG Website, http://www.ips.gov.au/INAG/, but is not completed because of limitation of resources. A reasonably reliable e-mail address list for INAG members has been compiled.

INAG has endorsed the SAO format for information derived from ionograms using automatic scaling techniques. This format was described in INAG-62 and the latest version is available on the Web at https://ulcar.uml.edu/~iag/SAO-4.htm.. As a result of INAG initiative, users of the world can see ionosonde data online through the internet. NGDC along with IPS and the University of Massachusetts Lowell has set up a system where user can login to display and analyze ionosonde data in real-time and through the WDC archives.

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G.2. Studies of the Ionosphere Using Beacon Satellites
Chair : R. Leitinger (Austria)
Vice-Chairs : J.A. Klobuchar (USA) and P.V.S. Rama Rao (India);
Working Group G.2 has a long tradition as the „Beacon Satellite Group" and deals with all aspects of ionospheric plasma effects on satellite signals observed on the ground or by receivers onboard satellites. The Working Group takes into account both scientific and applicational aspects and is truly interdisciplinary in its membership. Working Group G.2 seeks continuation and proposes to accept the following chairpersons who have been elected in a Working Group Assembly during the Beacon Satellite Symposium 1997:Reinhart Leitinger (Austria) as chairman,
Jack A. Klobuchar (USA) and P.V.S. Rama Rao (India) as co-chairmen
The Working Group G.2 communicates through correspondence and through its regular Beacon Satellite Symposia.. The Beacon Satellite Symposium 1997 at Sopron, Hungary, from June 30 to July 5, 1997 brought together 35 participants, including eight young scientists, from 15 countries (see section on URSI sponsored conferences). The Business Session reviewed once again the link to URSI Commission G and the internal structure of the Working Group with the conclusion that no changes are necessary. Another important topic was time and location of the next Beacon Satellite Symposium. In view of the continuing need for international cooperation and in view of the success of the Symposia, including especially BSS97, the group members present voted unanimously for a continuation of the Symposia series and for maintaining the traditional time interval of two to three years between Symposia. The d decision on the venue for the next symposium will have to take into account travel and local expenses on the one hand and available financial support on the other hand. The goal is to attract young scientists, and traditionally beacon satellite studies have found nearly global distribution.

G.3 Incoherent Scatter
Chair : A.P. van Eyken (Norway)
Vice-Chair : W. Swartz (USA)
There are presently ten Incoherent Scatter (IS) radars making regular observations throughout the world. These are located near Arecibo (Puerto Rica), Boston (USA), Irkutsk (Russia), Jicarmarca (Peru), Kharkov (Ukraine), Kyoto (Japan), Longyearbyen (Svalbard), Sondrestromfjord (Greenland), and two at Tromso (Norway). The ISWG's principal activity is the creation and execution of a series of coordinated IS Radar observing intervals during which all the world's IS radars attempt to observe. About 20 days of such coordinated activity are scheduled each year, the dates are carefully arranged in conjunction with other instrument programs and significant geophysical events and are published in the International Geophysical Calendar. The data from these intervals also form the main component of the IS Radar data held in the World IS database maintained by NCAR in Boulder, USA.
During the last three years, the observing schedule has been developed through email contact between the members of the Working Group followed by publication of a straw-man schedule on the World Wide Web (WWW) and subsequent refinement following discussions at various meetings. The number of days of observations as risen by general agreement by about 10 percent with most periods dedicated to the aims of specific major programs. An important innovation of the last two years has been the scheduling and operation of 'floating' observations where alert intervals have been scheduled one year ahead but the exact timing of operations has been decided much later based on actual geophysical conditions. Several of the IS radars now routinely distribute analyzed data in real time via public links on the WWW and demand for existing and new data sets continues to grow both for individual studies as in collaboration with other instruments, satellites and models. Since the last General assembly, a new IS radar facility has come into operation at high latitude in the European sector and plans are well developed to locate, at least part of the time, a further radar at even higher magnetic latitude in the American sector.

G.4 Ionospheric Informatics
Chair : S.M. Radicella (Argentina)
Vice-Chair : R. Hanbaba (France)
Working Group G4 held three meetings at the International Center for Theoretical Physics (ICTP) in Trieste, Italy, during the IRI Task Force Activity meeting. Formatting and exchange of ionospheric data and applications software was the main objective. The URSI recommended SAO data format for ionogram characteristics has been expanded. The current status is documented in https://ulcar.uml.edu/~iag/SAO-4.htm. New databases for improved IRI bottomside profile parameters were established. Results are given in the ITCP Reports IC/IR/99/5 (June 1999), IC/IR/98/9 (September, 1999), and IC/IR/97/11 (November 1997).
 
 

The Commission participated in the following Joint and Inter-Union Working Groups:

CGH.1. Wave and Turbulence Analysis
Co-Chair for Commission G : A.W. Wernik (Poland)
Co-Chair for Commission H : F. Lefeuvre (France)
EGH.1. EM Effects Associated with Seismic Activity
Co-Chair for Commission E : T. Yoshino (Japan)
Co-Chair for Commission G : O.A. Pokhotelov (Russia)
Co-Chair for Commission H : M. Parrot (France)
GF.1. Middle Atmosphere (this is the former AFG.1)
Co-Chair for Comm. G : J. Röttger (Sweden)
Co-Chair for Comm. F : C.H. Liu (China, SRS)
GFA.1. Ionosphere and Atmosphere Remote Sensing using Global Positioning Systems (GPS/GLONASS)
Co-Chair for Commission G : P. Høeg (Denmark)
Co-Chair for Commission F : F. Solheim (USA)
Co-Chair for Commission A : P. Banerjee (India)
GH.1. Active Experiments in Plasmas
Co-Chair for Commission G : Sa. Basu (USA)
Co-Chair for Commission H : T. Leyser (Sweden)
GH.2. Computer Experiments, Simulation and Analysis of Wave Plasma Processes
Co-Chair for Commission G : H. Thiemann (Germany)
Co-Chair for Commission H : H. Matsumoto (Japan)
 
 

URSI/IAGA VLF/ELF Remote Sensing of the Ionospheric and Magnetosphere (VERSIM)
Co-Chair for IAGA Commission 2 and 3 : A.J. Smith (UK)
Co-Chair for URSI Commission G and H : M. Parrot (France)

The working group serves as a forum for researchers studying the behaviour of the magnetosphere and ionosphere by means of ELF and VLF radio waves, both naturally and artificially generated. It is a joint working group constituted under the auspices of URSI - International Union of Radio Science (Commissions G and H) and IAGA - International Association of Geomagnetism and Aeronomy (Divisions II and III). Originally the emphasis was on probing of the magnetosphere by whistlers, but recently the scope has become somewhat broader. The group aims to promote research in this field by facilitating the exchange of ideas, information and experience between active research workers and other interested scientists. This is done through regular meetings at URSI and IAGA Assemblies, via the circulation of a newsletter, and through the World-Wide-Web. The group has also been active in sponsoring scientific symposia at IAGA and URSI Assemblies, in areas relevant to its field of interest, and in coordinating observational campaigns. At present the main areas of interest are Plasma structures and boundaries - morphology and dynamics, Wave-particle and wave-wave interactions, Wave-induced precipitation, Wave propagation in magnetospheres and ionospheres, and Sprites and the effects of lightning on the ionosphere.

Meetings of the VERSIM group at Lille and at the 1997 IAGA Assembly in Uppsala, Sweden, recommended that the working group continue in existence. The well-attended Lille meeting, held on 4 September 1996, was reported in VERSIM Newsletter No. 10. M. Parrot (France) was elected as URSI co-chair of the working group replacing U.S. Inan (USA) who was stepping down after 12 years service. A successful VERSIM half-day session (Session 2.14) on Localised ionospheric Perturbations related to lightning and VLF transmitters was convened by D. Nunn and A.J. Smith, and held on Monday 11 August 1997 during the IAGA Assembly at Uppsala, Sweden. It was a good session, attended by about 40 scientists. A meeting of the VERSIM Working Group also took place at Uppsala. Full reports of both these meetings were published in VERSIM Newsletter No. 12, and are also available on the VERSIM Web site. As a new initiative, a recent VERSIM bibliography has been compiled by M Parrot and is available on the VERSIM Web site. The VERSIM mailing list has now been replaced by an electronic mailing list which was set up in June 1999. For details see: http://www.nerc-bas.ac.uk/public/uasd/versim/vrsmeml.html. The list currently has 84 scientists from 21 different countries. There is an email directory on the VERSIM Web site. Four newsletters (Nos. 10-13) have been circulated since the 1996 URSI Assembly in Lille, in December 1996, July 1997, March 1998 and June 1999 respectively.
 
 

URSI-COSPAR on International Reference Ionosphere (IRI)
Chair : D. Bilitza (USA)
Vice Chair for COSPAR : K.I. Oyama (Japan)
Vice Chair for URSI: B.W. Reinisch (USA)

This inter-agency task force is mandated to develop the standard reference ionosphere. The main activity are the annual workshops. The 1997 IRI Workshop was held jointly with the European COST 251 Project at the Institute for Atmospheric Physics in Kühlungsborn, Germany from 27 to 30 May. The European Union Cooperation in Scientific and Technical Research (COST) project 251 deals with "Improved Quality of Service in Ionospheric Telecommunication System Planning and Operation". The Workshop focus was on "New developments in Ionospheric Modeling and Prediction". A selection of papers from the workshop was published in Volume 22, Number 6 of Advances in Space Research (32 papers, 918 pages). An IRI session on the "Lower Ionosphere - Measurements and Models" was held during the Scientific Assembly of the Committee on Space Research (COSPAR) in Nagoya, Japan, 13-15 July, 1998. 32 papers from the session were accepted for publication in Advances in Space Research. The 1999 IRI Workshop will be held at the University of Massachusetts in Lowell in the week just preceding the URSI General Assembly. Abstracts for 51 presentations have been submitted to the organizers. The annual IRI Task Force Activity continues at the International Center for Theoretical Physics (ICTP) in Trieste, Italy. During the week-long activity a team of about dozen experts tackles a set of very focussed and specific IRI modeling problems hands-on with the help of the ICTP computers and internet access.

The IRI Newsletter is published quarterly by K. Oyama (ISAS, Japan). Information about software updates and corrections are distributed through an electronic mailer to a list of more than 250 users. The WWW IRI interface of NSSDC records about 600 accesses per month and the IRI anonymous ftp site lists about 700 accesses per month. A proposal has been submitted to the International Standardization Organization (ISO) to make IRI the ISO standard for the ionosphere. A Windows/NT interface to the IRI software is under development at UML. The IRI model is recommended as standard in NASA (TM-4527) and ESA publications (System Engineering Space Environment, European Cooperation for Space Standardization, ESA, 1997).

The following conferences and meetings have been organized and attended by members of the URSI Commission G with URSI support in mode B:
 

1. Fifth International School / Symposium for Space Simulations

Kyoto, Japan, 13-19 March 1997
Representative for Comm. G: H. Matsumoto
Radio Science Bulletin, No 281, p. 13, June 1997

 

4. MST8: Eighth International Workshop on Technical and Scientific Aspects of MST Radar

Bangalore India, 15-20 December 1997
Representative for Comm. G: J. Röttger, Germany
Radio Science Bulletin, No 285, p. 32, June 1998

Since the beginning of the MST (mesosphere-stratosphere-troposphere) radar era in the middle 1970’s this workshop has become the standard ‘International Workshop on Technical and Scientific Aspects of MST Radar’. The four main topics included: Scattering processes, Atmospheric dynamics, Meteorology, New developments and facilities. A total of 130 scientists and engineers took part in MST8, where 52 were from outside India, and from 17 countries. A total of 162 papers were presented, whereof 124 were given orally and 38 displayed as posters. The final publication of extended abstracts in the workshop proceedings were published in the Handbook for STEP.

5. ESGAP 2, Electromagnetic Scattering from Gases and Plasmas

Lviv, Ukraine, 30 March - 2 April 1998
Representative for Comm. G: C. Hanuise, France
Radio Science Bulletin, No 281, p.14, June 1997

Topics included: Coherent scattering from space plasmas (ionosphere and magnetosphere), Coherent scattering from fusion plasmas (magnetic and inertial confinement), Collective scattering from aerodynamic flows, Bragg scattering from atmospheric turbulence, Scattering from condensed matter, Theory of scattering from turbulent media.

6. C4.1 - COSPAR Scientific Assembly ‘98

Nagoya, Japan, 12-19 July 1998
Representative for Comm. G: B. W. Reinisch, USA
Radio Science Bulletin, No 287, p. 20, December 1998

The session C4.1 Lower Ionosphere: Measurements and Models was organized by the COSPAR/URSI interunion Working Group on the International Reference Ionosphere (IRI) and was held the first three days of the 32nd COSPAR Scientific Assembly. The main topic was: Lower Ionosphere (the D and E region; altitude range from about 50 to 150 km). Different IRI half-day sessions dealt with the following topics: D Region Modeling, D Region Data, IRI Improvements - Middle Ionosphere, New Models and Data for IRI, Lower Ionosphere - Data, Ion Composition. A total of 46 papers was presented, including 17 invited, 12 contributed and 17 poster presentations.
 

7. 5th International Suzdal URSI Symposium

 
Moscow, Russia, 26-29 August 1998
Representative for Comm. G: S. Pulinets, Russia
Radio Science Bulletin, No 287, p. 22, December 1998

This symposium addressed the modification of the ionosphere by powerful radio waves. The program included the following topics: Powerful HF radio wave interaction with the ionospheric plasma, ELF-VLF waves excitation in the ionosphere and magnetosphere, Action of powerful microwave emission and particle injections on the Earth’s atmosphere, Modification of the ionosphere by electrostatic atmospheric electric field. The symposium attracted sixty participants from Germany, Finland, Norway, Russia, Sweden, Ukraine and the USA. There were 27 invited reports, 21 oral papers and 30 posters presented.

8. Workshop on Radio Methods for Studying Turbulence

Urbana, llinois, USA, 9-12 August 1999
Representative for Comm. G: A. Wernik, Poland
Radio Science Bulletin, No 286, p. 36, June 1998