The world's real-time space weather services are provided by the 10 Regional Warning Centres of the International Space Environment Service (ISES). IPS operates one of these centres which monitor and predict solar terrestrial activity and provide space weather forecasts and warnings for users who plan or conduct activities sensitive to solar terrestrial conditions.

The International Space Environment Service (formerly known as the International Ursigram and World Days Service ) is a joint service of URSI, IAU and IUGG and is a permanent service of the Federation of Astronomical and Geophysical Data Services (FAGS). During its existence ISES has had an important role in co-ordinating the exchange of data between organisations around the world who are involved in forecasting solar terrestrial conditions. These centres, known as Regional Warning Centres (RWCs), have the responsibility for collecting data from their geographical areas and exchanging these data through the ISES network. The data exchanged are highly varied in nature and in format, ranging from simple forecasts or coded information up to more complicated information such as images. An important strength of the data exchange system is that RWCs often have access to data from unique instrumentation available from the scientific community in its region. Exchange through ISES makes these data available to the wider international scientific and user community.

At present, there are ten Regional Warning Centres scattered around the globe. These centres are located in Beijing (China), Boulder (USA), Moscow (Russia), Paris (France), New Delhi (India), Ottawa (Canada), Prague (Czechoslovakia), Tokyo (Japan), Sydney (Australia) and Warsaw (Poland). A data exchange schedule operates with each centre providing and relaying data to the other centres. The centre in Boulder plays a special role as "World Warning Agency", acting as a hub for data exchange and forecasts.

The prime reason for the existence of the Regional Warning Centres is to provide services to the scientific and user communities within their own regions. These services usually consist of forecasts or warnings of disturbances to the solar terrestrial environment. The range of the locations of RWCs results in a very large diversity in the users of these forecasts. An important feature of the ISES system is that RWCs are able to construct and direct their services to the specific needs of their own customers.

Users of the services of RWCs include: high frequency (HF) radio communicators; mineral surveyors using geophysical techniques; power line and pipeline authorities; operators of satellites and a host of commercial and scientific users. The increasing sophistication and sensitivity of modern technology has resulted in a steadily expanding range of applications where a knowledge of the solar terrestrial environment is important.

In addition to its data exchange role, ISES provides several other services to the world scientific community. Firstly, ISES prepares the International Geophysical Calendar each year. This calendar gives a list of "World Days" which scientists are encouraged to use for carrying out their experiments. Prepared for ISES by the World Data Center-A for Solar Terrestrial Physics located in Boulder, the calendar is distributed widely to the scientific community and is also published in a number of scientific journals.

Secondly, on behalf of COSPAR, each month ISES summarises the status of satellite orbits around the earth and of space probes in the interplanetary medium in the Spacewarn Bulletin. Future launches are announced, actual launches are reported, new satellites receive an international designation, decays in the earth atmosphere are predicted and announced, and finally series of satellites useful for international participation are listed. This bulletin is produced by the World Data Centre-A for Rockets and Satellites located at the Goddard Space Flight Center in Greenbelt, USA.

The involvement of ISES in solar terrestrial data exchange leads naturally to an involvement in the analysis and interpretation of these data. To improve the accuracy and usefulness of solar terrestrial services, it is vital to better understand the sun-earth environment. As a result of this need, ISES has organised a series of "Solar Terrestrial Prediction Workshops" with the aim of bringing together scientists, forecasters, and the users of these forecasts. There have been five meetings in this series: USA (1979); France (1984); Australia (1989); Canada (1992); and Japan (1996). Each meeting has been very successful, bringing together more than 100 scientists, forecasters and users in a stimulating environment directed towards improvement of forecasting. An important outcome of each meeting has been the collection of papers into the "Workshop Proceedings" which have served as invaluable reference material for those interested in the field.

For much of its early existence, ISES made use of communication methods such as telex and of simple coded data. Recently, modern communication technology has resulted in a dramatic change, especially with the increasing use of electronic mail networks. These networks greatly enhance the range and speed of data flow, allowing data of greater complexity and volume to be transferred more rapidly. Where once limited by the availability of data, ISES finds itself in the position where the main limitations are now related to the handling of data and the interpretation. The changes in communication technology have also been of great benefit to the services provided by RWC's by improving their accessibility to clients.

ISES has much to take pride in during the years of its operation as the international co-ordinator of solar terrestrial data exchange and forecasting. The future, with expanded communications and a better understanding of the science of the solar terrestrial environment, also looks full of excitement and challenge.

For more information and references to other ISES centres see the ISES Page on the Web.

Material Prepared by Richard Thompson. © Copyright IPS - Radio and Space Services.