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Jean-Louis Le Mouel: A New Era for Geomagnetism
Satellites dedicated to the measurements of the magnetic field
of the Earth have been flying again for five years, and there is
little doubt that, from now on, the geomagnetic field will be continuously
monitored from space. The array of ground magnetic observatories,
which will remain a necessary complement to magnetic satellites,
has been reviewed and implemented, even though much remains to be
done. Data from land and marine expeditions have been collected,
providing an invaluable description of the field for the last centuries:
- Archeomagnetic measurements have seen a period of increased
activity, giving more reliable and more global information on
the field over the last few thousands years.
- Paleomagneticians pursue their gigantic task of deciphering
the behaviour of the field over geological times, putting special
emphasis on intensity measurements.
The extension of the accessible domain of time and space scales
will lead to qualitative changes in the description of the geomagnetic
field; for example, one will be shortly able to model the present
day field in its whole and in quasi-real time, without using the
awkward separations, averaging, and approximations which were necessary
in the past. Progress in understanding the various sources of the
field will follow, in particular the dynamo mechanism of the main
field, already so vigorously investigated, but also some features
of the magnetospheric systems of currents. And a more comprehensive
knowledge of the solar-terrestrial relationship is to be expected.
Daniel Baker: IGY + 50 and eGY
During the International Geophysical Year (1957-1958), member countries
established geophysical observatories around the world. These nations
were pursuing major IGY objectives - to collect geophysical data
as widely as possible and to provide free access to these data for
all scientists around the globe. By the beginning of the 21st century,
we had achieved an unparalled ability to acquire data and attained
a good understanding of traditional regions - the troposphere, the
magnetosphere, and other such "spheres". Much of the new
and important science now is coming from the study of the boundaries
between these regions and of coupling between geophysical domains.
Thus, we need to make data available in a readily accessible form
and much greater quantities to a wider range of scientists than
ever before. Several major international initiatives - such as the
International Polar Year, the International Heliophysical Year,
and the International Year of the Planet Earth - have been proposed
to commemorate and to follow on from the original IGY. This lecture
will review the goals, and present status of these programs. As
an important part of IGY+50, an International Association of Geomagnetic
and Aeronomy (IAGA) task group has recognized that a key achievement
of the IGY was the establishment of a worldwide system of data centers
and physical observatories. It has been agreed that for the 50th
anniversary of IGY, scientific societies should promote the establishment
of a system of Virtual Observatories. This can provide a forward
impetus to geophysics in this century similar to that provided by
the IGY fifty years ago. The proposed electronic Geophysical Year
(eGY) concept embraces all available and upcoming geophysical data
(e.g., atmospheric, geomagnetic, gravity, ionospheric, magnetospheric,
etc.) and would organize them into a series of virtual geophysical
observatories "deployed" in cyberspace. This concept implies
free access to all available data through the Internet and World
Wide Web, taking advantage of existing networking hardware and software
technologies (e.g., Internet, XML, Semantic Web, etc.). The eGY
can be smoothly incorporated into the various planned "International
Year" initiatives and will provide an international focus for
a resolve to address the issues of data release, data discovery,
and data preservation.. The eGY initiative is pragmatic and affordable
and has been embraced by all IUGG Associations.
David Loper: Earth's Magnetic Field and Life
This talk will focus on the role of the geomagnetic field in the
evolution of life on Earth. The key connection is water, which is
essential for life. Water exists on Earth because the magnetic field
has shielded it from erosion by the solar wind. The magnetic field
is sustained by a dynamo in the core that requires rapid cooling
of core and mantle. This cooling is provided by plate tectonics,
which needs water to lubricate the subduction zones. This closed
loop (the field preserves water which permits plate tectonics, thus
providing the cooling necessary to generate the field) will be illuminated
by comparing Earth with the state of Mars and Venus. As time permits,
other aspects of the relation between the magnetic field and life
will be discussed, such as the purported relation between field
reversals and extinctions, biomagnetism and the development of civilization.
Sunanda Basu: Climate and Weather of the Sun-Earth System:
SCOSTEP's New Interdisciplinary Research Program (CAWSES)
Climate and Weather of the Sun-Earth System (CAWSES), the new,
program for 2004 - 2008 developed by ICSU's interdisciplinary body
the Scientific Committee for Solar Terrestrial Physics (SCOSTEP),
aims to bring together the world's scientists in a cooperative effort
to study the entire interactive Sun-Earth system. SCOSTEP recognizes
the very impressive past, present, and planned space missions; ground-based
observations; and theory, modeling, and data analysis efforts aimed
at understanding aspects of this coupled system. CAWSES, seeks to
mobilize the international solar-terrestrial science community to
fully utilize such data archives, and future data streams; to produce
improvements in space weather forecasting, design of space- and
Earth-based technological systems, and understanding the role of
solar-terrestrial influences on Global Change. The CAWSES Science
Steering Group has organized the program around five themes: Solar
Influence on Climate, Space Weather: Science and Applications, Atmospheric
Coupling Processes, Space Climatology, and Capacity Building and
Education. CAWSES seeks to partner with the International Living
with a Star Program comprising space organizations engaged in missions
to explore the Sun-Earth coupled system. The aim of this talk is
to provide information to the international science and applications
community on the CAWSES goals, objectives and implementation plans
and to solicit inputs for future updates of the science plan. Some
results from the first Space Weather and Atmospheric Coupling Campaigns
held during March-April, 2004 will also be discussed.
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