|
Avalanching systems are very ubiquitous in nature. They are often
related to self-organized criticality (SOC), although the
avalanching feature is more general.
SOC has been proposed as a universal
mechanism for the behaviour of a wide class of statistical systems
and phenomena
(magnetic substorms, solar flares, earthquakes, rainfall, forest
fires, etc.). Research in this area mainly concentrates on what is
considered to be the basic features of avalanching systems and SOC in
particular: statistics of
avalanches, self-similarity, and large correlation length. Despite
substantial efforts, no physical system with firmly established SOC
behaviour has been observed: existence of a critical state without
tuning parameter in avalanching observed avalanching systems has not
been proven. Universal features of avalanching models have been
extensively studied. Nevertheless, applicability of this studies to
real physical systems in still under question. This is partly because of the lack of
studies of what and how should be measured in real systems to
identify manifestations of SOC and to relate the internal (not
directly observable) processes to measurable parameters.
The objective of the proposed research
is to properly establish what physical variables (output) should be studied
in real physical systems (like magnetosphere or earthquakes) in order
to make firm conclusions about presence or absence of SOC and study
the relation between the driving (input) and microprocesses in the
avalanching systems and the output. As a
result of the hopefully successful research we will have
appropriate tools to distinguish SOC systems from non-SOC ones and
will be able to conclude about the microprocesses in avalanching systems from
observations of some macroscopic variables.
|
Team:
|
|
Michael Gedalin (Ben-Gurion University, Beer-Sheva, Israel, team leader)
|
|
Michael Balikhin (ACSE, Sheffield University, Sheffield, UK)
|
|
Daniel Coca (Electrical Engineering and Electronics,
University of Liverpool, UK)
|
|
Giuseppe Consolini (Istituto di Fisica dello Spazio Interplanetario, Roma, Italy)
|
|
Rudolf Treumann (Max-Planck-Institute for extraterrestrial Physics, Roma, Garching, Germany)
|
|
Michal Bregman (Associated Member) (Ben-Gurion University, Beer-Sheva, Israel)
|