Astronomical insolation forcing

The aim of the astronomical theory of paleoclimates is to study the relationship between insolation and climate at the global scale. It comprises four different parts: computation of the astronomical elements, computation of the appropriate insolation parameters, development of suitable climate models and analysis of geological data in the time and frequency domains in order to investigate the physical mechanisms, to calibrate and to validate the climate models.

FORTRAN programs available:

The programme and data files for the computation of the orbital parameters and the insolation can be downloaded from this site.

Download the program and the report according to Berger [1978]. This solution is suitable to compute from present-day values back to 800 thousands of years ago (800 kyr BP).

Download the orbital parameters and insolation values according to Berger and Loutre [1991]. This solution is recommended to compute from present-day back to millions of years ago. For periods up to the last several hundreds of kyr, Berger [1978] solution is suggested by the author.

Other solutions valid up to 20 to 50 million years ago are proposed by Laskar [1993; 2004] from the "Institut de mécanique céleste et de calcul des éphémérides" (France). They can be found here.

Related people: André Berger, Marie-France Loutre

References:

• Berger A., 1978. Long-term variations of daily insolation and Quaternary climatic changes. J. Atmos. Sc., 35(12), 2362-2367.
• Berger A. and Loutre M.F., 1991. Insolation values for the climate of the last 10 million years. Quaternary Science Reviews, 10, 297-317.
• Laskar, J., F. Joutel. and F. Boudin, 1993. Orbital, precessional, and insolation quantities for the Earth from -20 Myr to +10 Myr, Astron. Astrophys. 270, 522.