Commission G

Commission G

1997 - 1999 triennium report

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 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 the Proceedings with 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 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 (the latest version was available until recently on the Web). 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 users can login to display and analyze ionosonde data in real time and through the WDC archives.

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 application 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 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. 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)

Working Group GF.1 has organized and supported a large number of sessions at conferences as well as workshops and symposia. A topical session on "Ionosphere and Atmosphere Sounding Applying New Methods" was held at the German URSI Meeting in Kleinheubach 6-10 October 1997. Eight papers resulting from the session "Advanced radar studies of the ionosphere and middle atmosphere" at the URSI General Assembly in Lille, France, were published in Radio Science. The School on Atmospheric Radar (SAR) on 10-13 December 1997 in Tirupati/Gadanki, India, produced extensive lecture notes that were printed with ISRO support. The 8th International Workshop on Technical and Scientific Aspects of MST Radar (mst8) took place thereafter on 15-10 December 1997 in Bangalore, India. Both activities were sponsored by URSI through Commissions F and G. At mst8, five Permanent Working Groups on "System calibrations and definitions", "Analysis and data validation", "Accuracy and requirements for meteorological applications", "International collaborations" and "Studies of transient phenomena" were established or reaffirmed. The Proceedings of mst8 were published as part of the Solar-Terrestrial Energy Program publications of SCOSTEP. Reports on mst8 and SAR were published in the Radio Science Bulletin and the International SCOSTEP Newsletter. A symposium on "Mesopause region structure, dynamics and composition" was organized for the 32nd COSPAR Scientific Assembly in Nagoya, Japan, 12-19 July 1998, sponsored by URSI through GF.1. Two special sessions "Ionospheric irregularities" and "Radar observations of the Earth's atmosphere" at the Western Pacific Geophysics Meeting 21-24 July 1998 in Taipei, Taiwan were convened as GF.1 activities. Papers from Session C2.1 were published in Advances of Space Research. An extended four-day plenary session on "Radar observations of the Earth's ionosphere and atmosphere" held at PIERS 1999 (Progress in Electromagnetics Research Symposium) in Taipei, Taiwan, 22-26 March 1999, was initiated by the WG. This session covered the topics: HF-radars (Digital Ionosondes, OTH Radar and SuperDARN), MF and meteor radars, MST radar and wind profilers, meteorological and weather radars, as well as incoherent and coherent scatter radars. Selected papers of this session will be published in a special issue of the Journal of Atmospheric and Solar-Terrestrial Physics. A session "Recent radar systems and scientific highlights in polar ionosphere and atmosphere research" is scheduled for the URSI General Assembly in Toronto. The GF.1 co-chair J. Röttger will present the Commission G tutorial at the URSI General Assembly: "Radar systems for ionospheric research". The Ninth International Workshop on Technical and Scientific Aspects of MST Radar - mst9 - will be combined with the final profiler conference of the COST76 European Commission project in Toulouse, France, 13-17 March 2000. The 3rd International School on Atmospheric Radar (isar3) will be held in connection with mst9-COST76 in March 2000 in Toulouse.

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)

The Working Group GH.1 on Active Experiments in Space Plasmas reports very enthusiastic response to its call for papers for this XXVIth URSI General Assembly. A session entitled, "Ionospheric Modification with High Power Radio Waves: Coupling of Plasma Processes" has been organized that features 15 oral presentations and 22 poster papers. The Working Group reports continued international cooperation in the field during the triennium. Co-operative research has been performed at the Sura, the EISCAT ionospheric modification facilities, in Russia and Norway respectively. The HF facility at the Arecibo Observatory and the newly emerging heating facility of HAARP (High Frequency Active Auroral Research Program) and HIPAS in Alaska have also supported similar activity. Research on Langmuir turbulence, SEE, artificial periodic inhomogeneities has been performed with great success. Breakthrough results on ionospheric irregularities have been obtained with the Cutlas radar and the Tromso heater. Magnetospheric turbulence experiments have been performed at HAARP as well as by heaters in Ukraine and Russia. The Working Group very regretfully records the untimely death of Dr. Lev Erukhimov of the Radio Physics Laboratory at Nizhny Novgorod. Dr Erukhimov's scientific enthusiasm and untiring efforts towards cooperative research in the area of ionospheric modifications will be remembered by the community.

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 behavior 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 Localized 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 activities 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 weeklong 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

This symposium provided a unique opportunity to facilitate the interactions and collaborations among the scientists and students working on space simulations, theories, and observations. Session topics included: Micro-scale phenomena, Meso-scale phenomena, Macro-scale phenomena, and New areas of research, Supercomputing. The total number of scientists and students participating was 182 from 14 different countries. A series of lectures on space physics and tutorials on simulation codes were given along with oral and poster presentations of recent results of theoretical, observational and simulation studies.

2. IRI/COST Workshop on New Developments in Ionospheric Telecommunications Systems Planning and Operations

Kühlungsborn, Germany, 27-30 May 1997

Representative for Comm. G: B.W. Reinisch

Radio Science Bulletin, No 283, p. 10, December 1997

This jointly organized meeting provided an opportunity for a large number of European scientists to present their IRI-related studies and to participate in the IRI improvement effort. Session topics included: Ionospheric models and HF propagation, E and D region, Topside ionosphere, Ionospheric storms and trough, Long-term variation and variability, Ion composition and plasma temperatures, Ion drift and spread F. There were 86 participants representing 21 countries, and more than 100 presentations. A special issue of Advances of Space Research has published selected papers.

3. Beacon Satellite Symposium 1997

Sopron, Hungary, 30 June - 5 July 1997

Representative for Comm. G: P. Bencze, Hungry

Radio Science Bulletin, No 284, p. 17, March 1998

The primary topics included: Ionospheric tomography with emphasis on results and including "space tomography", Electron content from networks of GNSS (Global Navigation Satellite System) receivers - replacement of classical methods (Faraday effect on signals of geostationary satellites) - data for nowcasting applications - data for near real time modeling, Electron content as input for regional and global ionospheric models, Progress in scintillation modeling with emphasis on satellite to satellite probation, and New experiments and requirements of novel applications of transionospheric propagation of radio waves. The symposium was attended by 35 participants from 15 countries, among them were 8 young scientist and graduate students. 38 papers were given orally, 6 were presented as posters. Written versions of the majority of the papers will appear in the journal "Acta Geodetica et Geophysica Hungarica".

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, and 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 extended abstracts of 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, Illinois, USA, 9-12 August 1999

Representative for Comm. G: A. Wernik, Poland

Radio Science Bulletin, No 286, p. 36, June 1998

The Workshop is intended to meet the general need for an exchange of information and ideas between scientists working on turbulence in various environments. It will bring together experts from all over the world that work on turbulence using radio methods. The main topics are Data analysis, Characterization and interpretation, and Theoretical results. The Workshop is a joint effort of URSI Commissions: E - Electromagnetic Noise and Interference, F- Wave Propagation and Remote Sensing, G - Ionospheric Radio and Propagation, H - Waves in Plasmas, and J - Radio Astronomy.

9. URSI/COSPAR International Reference Ionospheric Workshop

Lowell, MA, USA, 9-12 August 1999

Representative for Comm. G: B.W. Reinisch, USA

Radio Science Bulletin, No 288, p. 33, March 1999

The IRI annual meetings are the primary venue for improvements and refinements of the IRI representation of ionospheric electron density, electron temperature, ion composition and ion temperatures. Special emphasis for the 1999 Workshop is on Specification of the variability of ionospheric characteristics, The use of IRI for ray tracing studies and applications. Other topics include Comparisons of IRI with measurements and with other models, Suggested improvements and additions for IRI, and Applications of the IRI model. Attendees from 17 countries will present 48 papers.

In mode A Commission G sponsored:

1. Bianisotropics ’97 International Conference and Workshop on Electromagnetics of Complex Media, Glasgow, UK, 5-7 June 1997. The Radio Science Bulletin, No. 282, September 1997, p. 20.

2. ISRP’97: International Symposium on Radiowave Propagation, Qingdao, China, 12-16 August 1997. The Radio Science Bulletin, No. 283, December 1997, p. 14.

3. IWTS’98 - 1998 International Wireless and Telecommunications Symposium/Exhibition, Shah Alam, Malaysia, 11 -15 May 1998. The Radio Science Bulletin, No. 288, March 1999, p. 21.

4. International Workshop Day on Diffraction ’98, St. Petersburg, Russia, 2-4 June 1998. The Radio Science Bulletin’, No. 287, December 1998, p. 19.

5. COSPAR Scientific Assembly, Sessions C1.2, C2.1, C2.3, C2.6, D0.3, D0.8 -, Nagoya, Japan, 12-19 July 1998.

Bodo W. Reinisch

Chair, Commission G