The Milankovitch data were downloaded from: http://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/orbital_variations/berger_insolation/
. The were processed by program which allowed choice of month(s) and latitude range. (Reference: Berger, A., 1992, Orbital Variations and Insolation Database. IGBP PAGES/World Data Center for Paleoclimatology )
The graphs “Milankovitch cycles and temperature form Vostok ice core” and “Vostok ice core – temperature and CO2” are based on the files “vostok_deld.txt” and “co2nat.txt”. (References: Jouzel et al. (1987, 1993 and 1996) and Wahlen, M., et al, (2000), Vostok Ice Core CO2 Data, 1105-2856m.
The figure “Percentage of earth’s area on latitude bands” was prepared by digitising a Mollweide equal-area projection map of the earth.
The figure “Seasonal difference in albedo” was based on data from : Earth Radiation Budget Experiment (ERBE) S4G Global Clear-Sky Top Atmosphere Monthly Albedo at 2.5 and 1 Degree Resolutions (1986-1990). They were provided by the NASA Langley Research Center (LaRC) Distributed Active Archive Center (DAAC). Dr. Bruce Barkstrom was the Principal Investigator of the Earth Radiation Budget Experiment (ERBE). The original data sets can be accessed at the following web site: http://eosweb.larc.nasa.gov/PRODOCS/erbe/table_erbe.html