Advanced Forecast For Ensuring Communications Through Space


Equivalent slab thickness

The equivalent slab thickness is a measure of the width of the shape of the vertical electron density profile of the ionosphere. The equivalent slab thickness is defined by the ratio of the total electron content (TEC) and the peak electron density of the local ionosphere. To compute the peak electron density, vertical sounding data from different ionosonde stations are used. The corresponding TEC data are extracted from the SWACI TEC maps.

Usage of the equivalent slab thickness for ionosphere monitoring is described in e.g.:

N. Jakowski, S.M. Stankov, V. Wilken, C. Borries, D. Altadill, J. Chum, D. Buresova, J. Boska, P. Sauli, F. Hruska, Lj.R. Cander, Ionospheric behavior over Europe during the solar eclipse of 3 October 2005, Journal of Atmospheric and Solar-Terrestrial Physics, Volume 70, Issue 6, April 2008, Pages 836-853, ISSN 1364-6826, doi:

Gerzen, T., Jakowski, N., Wilken, V., and Hoque, M. M.: Reconstruction of F2 layer peak electron density based on operational vertical total electron content maps, Ann. Geophys., 31, 1241-1249, doi:

The plots below show on the left hand side the measurements of peak electron density foF2 and TEC and on the right hand side the derived slab thickness tau and the peak density hight hmF2.

Svalbard (78°N; 16°E)

Vertical Sounding Data supplied by Svalbard

Tromso (69.6°N; 19.2°E)

Vertical Sounding Data supplied by University of Tromso

Pruhonice (49°6'N, 14°3'E)

Vertical Sounding Data supplied by Ionospheric observatory Pruhonice of the Institute of Atmospheric Physics ASCR

Provision of Ionosonde Data

Ionosonde data are provided by the Tromsø Geophysical Observatory Faculty of Science and Technology, University of Tromsø, Norway.

Provision of TEC Data

TEC Data is generated by SWACI and provided for the AFFECTS consortium via:

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