From the stratosphere to the ionosphere: coupling, boundary conditions and assumptions

Solar radiation is the main source of input energy to the terrestrial atmosphere and, as such, it determines the Earth’s radiative balance and climate. There are multiple evidences showing how variations in the intensity of incident solar radiation at different wavelengths may affect all the layers of the atmosphere and the climate on annual, decadal and millennial timescales. Therefore, there is a strong scientific interest in developing climate models that properly describe all aspects of the solar forcing by also including the thermosphere and ionosphere, where solar UV flux and solar wind energy are essentially deposited.

However, the description of the terrestrial atmosphere from the surface up to the thermosphere and ionosphere is a very complex problem when dealing with the solar forcing on the climate. Thanks to numerous new observations and recent progress in our understanding of how the thermosphere/ionosphere reacts to solar forcing, several models have recently improved the description of the middle and upper atmosphere.

This workshop aims at comparing current numerical models for the middle and upper atmospheres and, in the light of the observations, identifying key issues, lacks and roads for future improvement.

Several leading specialists in the field will attend this workshop and describe their approach, present the difficulties, and discuss solutions. The programme will cover various aspects such as the ion-neutral chemistry, radiative transfer (linear and non-linear), the dynamic coupling between the stratosphere and the upper atmosphere, the EUV/UV solar flux (description and variability), its interaction with the upper atmosphere (heating and ionization), geomagnetic forcing induced by the solar wind variability and its interaction with the magnetosphere, energetic particle precipitation in the auroral regions and all the observations that could help to constrain these elements.

The goals of this workshop are to highlight the critical issues in model developments, discuss the choices that were made and foster collaborations between different teams.

This workshop is supported by the French Solar-Terrestrial Programme (PNST) and by COST Action ES1005 (TOSCA).


PhD students or postdoctoral scientists are welcomed to apply for a grant to support their travel expenses. Interested applicants should send to the organizers a one page CV and a title and abstract of their contribution to this workshop. Deadline to apply for a grant: 31 October 2012.


Registration is requested to attend to this workshop but there is no fee. The deadline for registration is 15 November 2012 and should be done at


Université Pierre et Marie Curie, 4 place Jussieu 75005 Paris, France

Metro Jussieu lines 7 and 10 (RATP)


26 and 27 November             Amphi Durand (Bâtiment Esclangon)

28 November                         Amphi 25 (at the bottom of tower 25)


                     Final programme


F. Leblanc (LATMOS/IPSL,

J. Lilensten (IPAG,

T. Dudok De Wit (LPC2E,


P. Keckhut (LATMOS/IPSL,

A. Hauchecorne (LATMOS/IPSL,

M. Marchand (LATMOS/IPSL,

F. Lefèvre (LATMOS/IPSL, franck.lefevre@latmos.ipsl.f)


Program outlines

1.  Description of the solar radiative input            
Convener: T. Dudok de Wit
Invited speakers: N. Krivova, G. Cessateur, I. Usoskin

2.  Modelling solar forcing from the surface to the upper atmosphere
Conveners: S. Bekki, P. Keckhut, A. Hauchecorne

Invited speakers: S. Melo, A. Seppälä, E. Rozanov, H. Schmidt, F. Forget,
A. Hauchecorne, A. Marchaudon, G. Thuiller
, K. Semeniuk
3.  Radiative transfer and chemistry
Conveners: M. Marchand, F. Lefèvre
Invited speakers: M. Lopez-Puertas, D. Marsh, M. Sinnhuber, P. Verronen

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