ClimateBook addendum: The following is the original readme file. The data itself, produced by the progam is in the file INSOLN.LA2004.MARSe.txt , which has been very slightly edited (header information and "e" replacing "D" in floats) relative to the original. =========================== ============================ ASTRONOMIE ET SYSTEMES DYNAMIQUES INSTITUT DE MECANIQUE CELESTE la2003 2004, May 27 =========================== ============================ The program insola is derived from the same program from the Earth paleoclimate solution La93 (Laskar, Joutel, Boudin, 1993) with several differences. The utilisation has been greatly simplified, as everything is now in a single application, insola, that allows to compute all insolation quantities for any time interval between the limits of the input files defined in insola.par (nomclimapos, nomclimaneg). Once the application is generated, the only file to edit is insola.par. We have provided two solutions with very close initial parameters La2003, and La2004. from -20 to + 10 Myr. La2004 should be the most up to date solution, but the difference gives an idea of the precision of the solution. We have also provide solutions over much longer times (200 Myr) for the same quantities for 5 different examples taken from (Laskar et al., 2003) which represent some typical and extreme behavior of the obliquity. They could be use to test climate models under various obliquity regimes. La2003 : ========== Main reference : Laskar, J., Gastineau, M., Joutel, F., Robutel, P., Levrard, B., Correia, A.,: 2003, Long term evolution and chaotic diffusion of the insolation quantities of Mars. {\it in preparation} ******************************************************************************** * Authors: J. Laskar, M. Gastineau, F. Joutel * * (c) Astronomie et Systemes Dynamiques, Institut de Mecanique Celeste, * * Paris (2003) * * * * Jacques Laskar * * Astronomie et Systemes Dynamiques, * * Institut de Mecanique Celeste * * 77 av. Denfert-Rochereau * * 75014 Paris * * email: laskar@imcce.fr * * * ******************************************************************************** CONTAINS: ========= File Summary: -------------------------------------------------------------------------------- FileName Explanations -------------------------------------------------------------------------------- README This file INSOLN.LA2003.MARS.ASC Nominal solution La2003, before present years (-21Myr to 0) INSOLP.LA2003.MARS.ASC Nominal solution La2003 after present years (0 to +11Myr) INSOLN.LA2004.MARS.ASC solution La2004, before present years (-21Myr to 0) INSOLP.LA2004.MARS.ASC solution La2004 after present years (0 to +11Myr) Makefile to compile and generate derived files insola.par Parameter file for insola. insola.f FORTRAN program for computations of various insolation quantities insolsub.f subroutines for insola.f prepsub.f FORTRAN subroutine for insola.f prepinsol.f FORTRAN subroutine for preparation step for insola.f -------------------------------------------------------------------------------- Byte-per-byte Description of file: INSOLN.LA2003.MARS.ASC Byte-per-byte Description of file: INSOLN.LA2003.MARS.ASC Byte-per-byte Description of file: INSOLN.LA2004.MARS.ASC Byte-per-byte Description of file: INSOLN.LA2004.MARS.ASC -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1-14 F8.3 1000yr t Time from J2000 in 1000 years 18-39 D23.16 --- e eccentricity 43-64 D23.16 rad eps obliquity (radians) 68-89 D23.16 rad pibar longitude of perihelion from moving equinox (radians) -------------------------------------------------------------------------------- Description: La2003 is the nominal solution for precessional quantities and orbital quantities of Mars. The solution La2003 is provided with fortran subroutine in order to compute the insolation quantities of Mars. The nominal solution La2003 of Mars is obtained with the following constants (p from Folkner et al., 1997 ) : - tidal coefficents : k2 = 0.14 Q = 50 - initial precession rate : p = -7.576 arcsec/year La2004 is the up to date insolation solution with initial conditions from (Yoder et al, 2003). The nominal solution La2003 of Mars is obtained with the following constants : - tidal coefficents : k2 = 0.149 Q = 92 - initial precession rate : p = -7.597 arcsec/year BIBLIOGRAPHY: ============ La90: Laskar, J.: 1990, The chaotic motion of the solar system. A numerical estimate of the chaotic zones Icarus, 88, 266 La93: Laskar, J., Joutel, F., Boudin, F.: 1993, Orbital, precessional and insolation quantities for the Earth from -20 Myr to + 10Myr Astron. Astrophys. 270, 522 La2003 :Laskar, J., Gastineau, M., Joutel, F., Robutel, P., Levrard, B., Correia, A., Long term evolution and chaotic diffusion of the insolation quantities of Mars. {\it in preparation} ================================================================================ ================================================================================ Compilation of the Program -------------------------- Edit the makefile to choose a fortran-90 compiler and run "make". Detailed Description of the Program ----------------------------------- insola.par : THE USER should edit the file insola.par to set all parameters. insola : interactive insolation computations -------------------------------------------------------------------------------- INSOLA.PAR The user should edit the parameter file insola.par. datefin : ending time (Myr) datedebut : starting time (Myr) pas : sampling step (in years). The default value is 1000. The minimum step is 1 year (it is usually not necessary for pas to be smaller than 100 (yr)). nominsolbin : Binary intermediate file for insolation nomclimapos : ASCII file for climatic variables for positive time nomclimaneg : ASCII file for climatic variables for negative time so : Solar constant expressed in W/m2 for Mars mean semimajor axis a4= 1.523679335D0 AU and solar constant at 1 AU so0 =1368 W/m2 so = so0 /a4^2 = 589.2 W/m2 Starting and ending date must verify : -10 <= datedebut <= 0 <= datefin <= +20 The user may restrict himself to e.g. -2Myr to 0 by putting instead datedebut=-2.D0 datefin=0.D0 -------------------------------------------------------------------------------- INSOLA The routines insola are designed to compute all necessary insolation quantities derived from the orbital and precessional quantities computed above. They are given on the form of FORTRAN code, so the user can check if they correspond to his needs. He can also design his own insolation routines. Insola will construct a binary intermediate file when this file is not present before computations. insola is a self documented program For more details, the user can refer to (Laskar et al, 2003) ================================================================================ User feed-back is encouraged. Unless otherwise specified, send comments and bug reports to: E-mail : laskar@imcce.fr Fax : (33) 1 40 51 20 55 Postal mail: Institut de Mecanique Celeste 77 avenue Denfert Rochereau F-75014 PARIS ================================================================================