Near-surface temperatures and heat balance of bare outcrops exposed to solar radiation

Auteur(s) et Affiliation(s)



Description :
The study site is a steep gneiss slope known as Rochers de Valabres (Alpes-Maritimes, France). Attention was focused on 2 major contributors to the heat balance; the heat flux entering the rock mass through conduction and the incoming shortwave (solar) radiation. A Fourier decomposition of the temperature measurements provided an estimate of the in situ thermal conductivity of the rock and was used to calculate the conductive term. The shortwave radiation term was determined on the basis of the pyranometer measurements adjusted to account for the angle of incidence of the sun. It is shown that, throughout clear-sky periods, heat exchanges at the surface are mainly controlled by direct solar radiation during the day, and by a roughly constant outgoing heat flux during the night. Subsurface temperatures can be reliably estimated with a semi-infinite medium model whose boundary condition is derived from an analytical insolation model that takes atmospheric attenuation into account.


Type de document :
Article de périodique

Source :
Earth surface processes and landforms, issn : 0197-9337, 2011, vol. 36, n°. 12, p. 1577-1589, nombre de pages : 13, Références bibliographiques : 1 p.

Date :
2011

Editeur :
Pays édition : Royaume-Uni, Chichester, Wiley