Checked content

File:Vostok Petit data.svg

Description La bildo estas kopiita de wikipedia:en. La originala priskribo estas: Graph of CO2 (Green graph), temperature (Blue graph), and dust concentration (Red graph) measured from the Vostok, Antarctica ice core as reported by Petit et al., 1999. Higher dust levels are believed to be caused by cold, dry periods. The Earth's orbital eccentricity, tilt, and precession vary in a pattern over thousands of years. The IPCC notes that Milankovitch cycles drove the ice age cycles; CO2 followed temperature change "with a lag of some hundreds of years" (visible on a graph more zoomed in than this); and that as a feedback amplified temperature change. Among other factors, CO2 is more soluble in colder than in warmer waters.
Date 2010-06-20 13:24 (UTC)
  • derivative work: Autopilot ( talk)
Lissajous small.svg
This vector image was created with gnuplot.
Applications-graphics.svg This is a retouched picture, which means that it has been digitally altered from its original version. Modifications: Generated as svg. The original can be viewed here: Vostok-ice-core-petit.png. Modifications made by Autopilot.

Data sets used are:

gnuplot commands:

unset multiplot
set term svg size 1024,768
set output "vostok-data.svg"

set border 3
set xtics nomirror
set ytics nomirror
unset xlabel
unset ylabel

set grid y
set multiplot layout 3,1

set ylabel "°C"
plot [0:425] \
        "deutnat.txt" \
        using ($2/1000):4 \
        title "Temperature variation (ΔT)" \
        ls 3 \
        with lines

set ylabel "ppmv"
plot [0:425] \
        "co2nat.txt" \
        using ($1/1000):2 \
        title "Carbon Dioxide" \
        ls 2 \
        with lines

set xlabel "Thousands of years ago"
set ylabel "ppm"
plot [0:425] \
        "dustnat.txt" \
        using ($1/1000):2 \
        title "Dust concentration" \
        ls 1 \
        with lines

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