Sandpile Paradigm was proposed by Bak, Tang and Wiesenfeld [1] to explain simple model of Self-
Organized Criticality (SOC). When the sand fall on the sandpile (input: driver), we will see, that at
some critical point (reaching adequate angle), sand will slide down to get the saturation phase. Here the gravity plays the energy input role (see [2]).
We can conclude that for earthquakes phenomenon energy input is tectonic stressing, criticality
(instability threshold) is the dynamical friction and energy output is the rupture area.
In astrophysics, for example, magnetospheric substorms exhibits itself as a SOC systems. Solar wind plays the energy input role, magnetic reconnection is the instability threshold (criticality) and
auroral bursts are the intermittent avalanches (output).
The SOC approach has been already used for interpretation of magnetospheric processes and
recently for the Earth's Auroral Kilometric Radiation [3,4]. Data gathered by the POLRAD swept
frequency radiospectrograph (Interball–2 mission) have been used for a preliminary analysis of a
number of short bursts of the Auroral Kilometric Radiation (AKR) as a function of their intensity.
REFERENCES
[1] Bak, P., C. Tang, K. Wiesenfeld, Self-organized criticality: an explanation of 1/f noise.
Phys.Rev. Letters 59(4): 381-384, doi:10.1103/PhysRevLett. 59.381,1987
[2] Aschwanden, M.J., Crosby, N.B., Dimitropoulou, M., Georgoulis, M.K., Hergarten, S.,
McAteer, J., Milovanov, A.V., Mineshige, S., Morales, L., Nishizuka, N., Pruessner, G., Sanchez,
R., Sharma, A.S., Strugarek, A., Uritsky, V., 25 years of self-organized criticality: Solar
and astrophysics. Space Sci. Rev. 198, 47. doi 10.1007/s11207-016-0910-5, 2016
[3] Marek, M., and R. Schreiber, Is the AKR Cyclotron Maser Instability a self-organized
criticality system? In Planetary Radio Emissions VIII, edited by G. Fischer, G. Mann, M.
Panchenko, and P. Zarka, Austrian Academy of Sciences Press, Vienna, 269 -277, 2017
[4] Marek, M., and R. Schreiber, Can the Auroral Kilometric Radiation be a Self-
Organized Criticality System? Earth and Space Science, Volume 9, Issue 5, article id. E02148,
doi 10.1029/2021EA002148 , 2022