1. SWWT Initiatives - Long term monitoring of Sun-Earth Interactions
F. Lefeuvre
+ contributions from 16 groups or individual SWWT members

2. CONTEXTE
SW activities rely on long term ground-based and space - based observations
Long term monitoring of the geospace (solar corona, solar wind, magnetosphere, ionosphere, atmosphere) is needed:
- to understand physical mechanisms driving Solar – Earth interactions
- to identify time variations in the Earth environment (space environment included)
- to provide SW services (forecast and specifications)
Part of the observations are known to be temporary (e.g. SOHO)
Other observations, continuously available since many years e.g. magnetometers or ionosondes) may be stopped due to changes in the priorities of National Agencies

3. The dual use of instruments (science and operational activities), which should be an advantage, may be viewed as a drawback
SWWT action in progress : investigate the possibility of creating a european coordination structure (like ERANET) between all national and international agencies involved (or to be involved) in long term monitoring (long term measurements, access to distributed data sets with large data volume, model development ).
An ERA-NET (e.g. ASTRONET) does not provide new funds but allows to agree on common strategies and common support of programmes.
Three splinter meetings have been organized to identify tasks for an ERANET-like structure.
- Paris meeting, elaboration of a questionnaires sent to all SWWT members
- Toulouse and RAL meetings, discussion on elements of the questionnaire.
The work is not completed.

4. 2. OUTPUTS OF THE QUESTIONNAIRE - an example : the networks of g. b
2. OUTPUTS OF THE QUESTIONNAIRE - an example : the networks of g.b. magnetometers - synthesis

5. 2.a The ground-based magnetometers
What must be monitored
The time and space variations of the Earth magnetic field for time periods ranging from few minutes to few decades in order to:
- Earth magnetism,
- dynamics of the auroral/polar regions,
- determine the ionospheric current during SW storms,
- produce geomagnetic indices and geomagnetic field models,
- enable the calculation and estimation of the induced geoelectric field and of the resulting GICs in technological systems
Users are research institutes and industrial companies

6. Present status, National and European funding
- about 100 digital observatories (funded by National Agencies) are gathered in the frame of the INTERMAGNET* network
- it is completed by more or less temporary magnetometers (funded by National Agencies) run by other networks like IMAGE**
- the worlwide coordination of magnetic observatories is made in the frame of an ad-hoc IAGA working group
* INTERMAGNET, consortium led by an executive board (4 scientists), the technical issues and standards are under the responsabilty of an operating committee (14 scientists)
** IMAGE, informal coalition between 10 European research institutes who maintain magnetometers in northern Europe

7. What are the gaps in the measurements and the lack of coordination
- no gap in stations for Europe (planetary scale , regional scale ?)
- coordination via IAGA (+ an internal coordination system for INTERMAGNET)
Benefit of a cooperation between National and European organisms
- Cooperation allows reduction of costs and high level technological infrastructure

8. 2.b Synthesis

9. Interest of a coordination
Quantities
to monitor
Equipments
Present driver
Funding agencies
Interest of a coordination
time and space Earth B field variations (Earth magnetism,dynam.
Aur./polar regions)
space and g.b. magnetom.
Science
(ind. users)
National
- maintain ( upgrade) technical performances
Cosmic ray fluxes and int. (effects on the Earth environt)
g.b. neutron and muon monitors
Internat.
- have data in line and archived
The structure of the ionosphere
ionosondes
Application
(sci. users)
EU**
- secure the funding
TEC variations
Space and g.b. GNSS receivers
Application*
(Sci. developt)
ESA**
- Secure the funding
* Creation of an United Nation International Committee for Global Navigation System
(see UNOOSA + ICG)

10. Interest of a coordination
Quantities
to monitor
Equipments
Present driver
Funding agencies
Interest of a coordination
High latitude ionosphere convection, conduction,
(modelling)
Super –DARN
EISCAT
Science
Intern. associations
define a medium and long term strategy for long term monitoring
Scintillations
receivers
Science?
Applic.* ?
National
Internat.
data exchange
Solar activity
g.b. (space ?)
Magnetographs
Coronographs
H- α imagers
(Ind. Users)
define a medium and long term strategy for g.b. and space measurements
Solar energy flux (understanding irradiance variations,
therm – ionosph. Res.)
Space EUV/UV detectors
g.b. F10.7 cm measurements (for proxy)
TIGER SCOSTEP programme?
- secure the continuity of F 10.7 cm measurements
- define a strategy (ISS?)

11. Interest of a coordination
Quantities
to monitor
Equipments
Present driver
Funding agencies
Interest of a coordination
Coronal hole obs. (for CME prediction and detection)
EUV soft x-ray images
Science
National
Internat.
define a medium and long term strategy for long term monitoring
Solar radio flux, signature of CMEs, shocks, SEP, ..
Multi – frequency radiotelescopes
(Ind. Users?)
IMF and solar wind parameters at L1
Plasma and wave measurements on-board satellites
Use by science as well as by application
Define a European strategy

12. General situation for Space – based measurements Long term measurements (a) solar corona and solar wind (b) radiations Present situation - (a) supposed to be taken into account by ESA/Sci. - (b) is the mission of the ESA project of Tech network of Centers Problems - (b) needs (a) - (b) has a scientific part (ILWS)

13. 3. INTEREST OF AN INTER-AGENCIES COORDINATION STRUCTURE
Ground-based measurements
- secure the funding
- optimize the space, time and frequency coverage
maintain and improve the technical performances
define strategies for long term monitoring measurement (e.g. support of proposals for new networks)
International equipments
- define European medium and long terms strategies
Space – based measurements
- facilitate dual use of satellites and ISS (Science, Earth Observation and technical satellite, etc.) or even dual satellites

14. Access to distributed data sets with large data volume
Access to distributed data sets with large data volume ● get EU supports for data exchanges, archiving, Virtual Observatories (in particular via upstream actions) Model development ● prioritize models to be developed (and so supported) ● examine the possibility of developing European global models

15. 4. CONCLUSION
long term monitoring is essential for scientific as well as operational SW activities. Approaches may-be different for ground-based measurements and for space based measurements. Access to data and model developments are complementary problems.
Ground based measurements
- National scientific agencies, which don’t like long time long term commitments, must be convinced about the scientific objectives to fund equipments
- Recommendations from Scientific Unions and/or Interdisciplinary Bodies may help to convince Scientific Unions
- IHY may give an opportunity to start new long term monitoring (as an example : The monitoring of solar radio flux, signature of CMEs, shocks, SEP, ... from a network of multi-frequency radio telescopes)
- question: what about the user needs?

16. Space – based measurements
- adapted strategies must be defined for long term monitoring from space
- coordination is needed
between ESA departments
between ESA and National Space agencies
with other European Space entities (EUMETSAT)

17. In all cases, a coordination between all partners would be very useful
An ERA-NET could be a solution. This proposal has first to be tested with ASTRONET