Grönlannin NGRIP-jääkairausnäytteestä mitattujen kaasukuplien kaasupitoisuuksien mukaan metaanin CH4 määrä (vihreä) nousi äkisti jääkauden lopussa, samoin kuin jään raskaan hapen määrä delta-O18:kin (punainen). Delta-O18 mittaa lähinnä lämpötilaa, metaanin määrä ehkä ikiroudan sulamista tai soistumista. Metaanin ja raskaan hapen ajoitukset ovat hieman eri menetelmillä saatuja, jolloin käyrät eivät ole tahdissa.
English: End of ice age methane and temperature related data curves from Greenland NGRIP ice core. There was rapid transition from cold to warmer conditions around North Atlantic ocean. Younger dryas/preboreal limit is seen on delta-O18 and (d-O18) methane (CH4) curve in data extracted from NGRIP ice core. Curves .pnf iaege roduced with Gnuplot 4.6 win Note: grip all text from data files, if ypou use Gnuplot! Delta-Oxygen-18 data comes from ftp://ftp.ncdc.noaa.gov/pub/data/paleo/icecore/greenland/summit/ngrip/gicc05-20yr.txt IGBP PAGES/WDCA CONTRIBUTION SERIES NUMBER: 2006-118 NAME OF DATA SET: Greenland Ice Core Chronology 2005 (GICC05) LAST UPDATE: Released 27 November 2006, received by WDC #Paleo 12/2006. Original file name: GICC05_NGRIP_GRIP_20y_27nov2006 SUGGESTED DATA CITATION: NGRIP dating group, 2006. Greenland Ice Core Chronology 2005 (GICC05). IGBP PAGES/World Data Center for Paleoclimatology Data Contribution Series # 2006-118. NOAA/NCDC Paleoclimatology Program, Boulder CO, USA. Methane data comes from ftp://ftp.ncdc.noaa.gov/pub/data/paleo/icecore/greenland/summit/ngrip/gases/ngrip2012ch4.txt NGRIP Ice Core 32-11KYrBP Methane Data "Date: 10-17-2012 Authors: M. Baumgartner, A. Schilt, O. Eicher, J. Schmitt, J. Schwander, R. Spahni, H. Fischer, and T. F. Stocker Journal Name: Biogeosciences Published Title: High-resolution interpolar difference of atmospheric methane around the Last Glacial Maximum Published Date: 10-16-2012 DOI: 10.5194/bg-9-3961-2012 Gnuplot 4.6 script, very experimental one! !/gnuplot G N U P L O T Version 4.6 patchlevel 3 last modified April 2013 Build System: MS-Windows 32 bit Copyright (C) 1986-1993, 1998, 2004, 2007-2013 Thomas Williams, Colin Kelley and many others gnuplot home: http://www.gnuplot.info faq, bugs, etc: type "help FAQ" immediate help: type "help" (plot window: hit 'h') set terminal png nocrop font "Arial,15" fontscale 1.0 size 1280,960 set output unset clip points set clip one unset clip two set bar 1.000000 front set border 31 front linetype -1 linewidth 1.000 set timefmt z "%d/%m/%y,%H:%M" set zdata set timefmt y "%d/%m/%y,%H:%M" set ydata set timefmt x "%d/%m/%y,%H:%M" set xdata set timefmt cb "%d/%m/%y,%H:%M" set timefmt y2 "%d/%m/%y,%H:%M" set y2data set timefmt x2 "%d/%m/%y,%H:%M" set x2data set boxwidth set style fill empty border set style rectangle back fc lt -3 fillstyle solid 1.00 border lt -1 set style circle radius graph 0.02, first 0, 0 set style ellipse size graph 0.05, 0.03, first 0 angle 0 units xy set dummy x,y set format x "% g" set format y "% g" set format x2 "% g" set format y2 "% g" set format z "% g" set format cb "% g" set format r "% g" set angles radians unset grid set raxis set key title "" set key inside right top vertical Right noreverse enhanced autotitles nobox set key noinvert samplen 4 spacing 1 width 0 height 0 set key maxcolumns 0 maxrows 0 set key noopaque unset label set label 1 "(null)" at 0, 0, 0 left norotate font "Arial, 18" back nopoint offset character 0, 0, 0 unset arrow set style increment default unset style line unset style arrow set style histogram clustered gap 2 title offset character 0, 0, 0 unset logscale set offsets 0, 0, 0, 0 set pointsize 1 set pointintervalbox 1 set encoding default unset polar unset parametric unset decimalsign set view 60, 30, 1, 1 set samples 100, 100 set isosamples 10, 10 set surface unset contour set clabel '%8.3g' set mapping cartesian set datafile separator whitespace unset hidden3d set cntrparam order 4 set cntrparam linear set cntrparam levels auto 5 set cntrparam points 5 set size ratio 0 1,1 set origin 0,0 set style data points set style function lines set xzeroaxis linetype -2 linewidth 1.000 set yzeroaxis linetype -2 linewidth 1.000 set zzeroaxis linetype -2 linewidth 1.000 set x2zeroaxis linetype -2 linewidth 1.000 set y2zeroaxis linetype -2 linewidth 1.000 set ticslevel 0.5 set mxtics default set mytics default set mztics default set mx2tics default set my2tics default set mcbtics default set xtics border in scale 1,0.5 mirror norotate offset character 0, 0, 0 autojustify set xtics 100 norangelimit font "Arial, 18" set ytics border in scale 1,0.5 mirror norotate offset character 0, 0, 0 autojustify set ytics autofreq norangelimit font "Arial, 15" set ztics border in scale 1,0.5 nomirror norotate offset character 0, 0, 0 autojustify set ztics autofreq norangelimit set nox2tics set noy2tics set cbtics border in scale 1,0.5 mirror norotate offset character 0, 0, 0 autojustify set cbtics autofreq norangelimit set rtics axis in scale 1,0.5 nomirror norotate offset character 0, 0, 0 autojustify set rtics autofreq norangelimit set title "NGRIP YD/PB data" set title offset character 0, 0, 0 font "" norotate set timestamp bottom set timestamp "" set timestamp offset character 0, 0, 0 font "" norotate set rrange [ * : * ] noreverse nowriteback set trange [ * : * ] noreverse nowriteback set urange [ * : * ] noreverse nowriteback set vrange [ * : * ] noreverse nowriteback set xlabel "a BP" set xlabel offset character 0, 0, 0 font "" textcolor lt -1 norotate set x2label "" set x2label offset character 0, 0, 0 font "" textcolor lt -1 norotate set xrange [ 11000.0 : 12000.0 ] reverse nowriteback set x2range [ * : * ] noreverse nowriteback set ylabel "d-O18" set ylabel offset character 0, 0, 0 font "" textcolor lt -1 rotate by -270 set y2label "" set y2label offset character 0, 0, 0 font "" textcolor lt -1 rotate by -270 set yrange [ * : * ] noreverse nowriteback set y2range [ * : * ] noreverse nowriteback set zlabel "" set zlabel offset character 0, 0, 0 font "" textcolor lt -1 norotate set zrange [ * : * ] noreverse nowriteback set cblabel "" set cblabel offset character 0, 0, 0 font "" textcolor lt -1 rotate by -270 set cbrange [ * : * ] noreverse nowriteback set zero 1e-008 set lmargin -1 set bmargin -1 set rmargin -1 set tmargin -1 set locale "Finnish_Finland.1252" set pm3d explicit at s set pm3d scansautomatic set pm3d interpolate 1,1 flush begin noftriangles nohidden3d corners2color mean set palette positive nops_allcF maxcolors 0 gamma 1.5 color model RGB set palette rgbformulae 7, 5, 15 set colorbox default set colorbox vertical origin screen 0.9, 0.2, 0 size screen 0.05, 0.6, 0 front bdefault set style boxplot candles range 1.50 outliers pt 7 separation 1 labels auto unsorted set loadpath set fontpath set psdir set fit noerrorvariables GNUTERM = "windows" plot 'C:\gnuplot46\oma\ngripdo181_s13.txt' using 1:3 with lines lw 2 title "d-O18", 'C:\gnuplot46\oma\ngripch41_s23.txt' using 2:((($3-750)/50)-38) with lines lw 2 lc rgb "#005f00" title "CH4" EOF