Saturday, August 13, 2011

Comparisons of TempLS with reader MP's July 2011 plots.

In previous posts I've described the TempLS reconstruction of July 2011 global surface temperature. I noted also the new GISS average, and said that a comparison of the spatial plot would await GISS posting.

Commenter MP has been producing very impressive spatial plots using a Matlab script. I posted his movie of recent UAH LT temperatures here. In comments below you'll find the stills, and a wealth of other images linked by MP.

He has also done plots of GISS results, using GISS gridded data. I'll show below the jump his plots, and my spherical harmonics based reconstruction for comparison.

Here is MP's plot for July 2011. The two below are the GISS results, and are therefore directly comparable, with due allowance for the different color schemes.

Because it's grid-based, a larger interpolation length (1200km) fills more cells but lowers the resolution. For comparison, here is the TempLS plot, which is based on a spherical harmonics least squares fit, and so has even more smoothing:

MP, if you could send me your color scheme (looks like NOAA) I could use it instead of GISS (Update - done, thanks MP - mine looks like a lava lamp version now). In my previous post I used the full 1960-2011 period for the anomaly base, but I've reconfigured here to 1981-2010 to match MP. I've used a Hammer projection here - in my next post I'll show spherical projections augmented by javascript navigation, and using a 1951-1980 base to compare with GISS.

MP has also posted UAH

and RSS zonal plots.

Here is his full set of UAH monthly maps from Jan 2009 to Jul 2011.


  1. Tanks Nick,

    I've indeed used (a slightly adjusted) NOAA color scheme also known as GMT polar, here are the RGB triplets:
    179 0 0
    205 28 18
    230 78 52
    255 128 85
    255 166 123
    255 203 161
    255 227 200
    255 255 255
    192 224 255
    154 196 255
    114 157 255
    78 118 250
    45 67 225
    13 20 201
    0 0 170
    Maybe you already know the website cpt-city, it has a wealth of colour schemes in different formats collected by John James Green:

    Temperature schemes

    Most popular


  2. MP,
    Thanks - they seem to correspond, although the smoothing in the spherical harmonics fitting is now very evident. I'll check those temp schemes, but mainly now I'm just trying to match someone else's scheme.

  3. MP,
    Yes, thanks, those soliton pages are very good, especially the last.

  4. Hi Nick,

    I found it rather hard to make a good colormap, especially when a different baselines are used the visual effect can be dramatic. I've been experimenting with linear, quadratic and exponential bins. The combination of an increasing trend with large fluctuations is hard to visualize. I will give it another thought. Maybe a more complex scheme with more colours is better, such that colours around zero capture trend behaviour e.g. in the range of -1 to 1 in a more linear fashion and the extremes represented by exponential bin widths.