Sunday, August 14, 2011

GISS spatial map, July 2011

I said I'd compare the GISS spatial map for July 2011 with the TempLS fitted spherical harmonic version when the GISS map appeared. That has now happened. The patterns are similar, though TempLS seems to be somewhat warmer. That is partly because of the smoothing - some of the cold spots are localised, and tend to get smoothed over. Anyway, pictures below the jump.

Here is the GISS plot:

And below is the plot that I showed here:

I've tried hard to match the colors and levels, and I don't think they are the major source of the differences, although my corresponding colors, theoretically an exact match, do seem fainter in the PNG rendition. I think part is the smoothing.  The actual patterns are very similar.

In my lat/lon plot TempLS cuts out the parts near the poles (eg below 60°S), because of the distortion. But you can see them in the Hammer projection here and I'll be showing full spherical projections (with some Javascript) in my next post. TempLS shows a major warm spot around the South Pole - but based on very few stations. GISS has some of that too, but the projection makes it hard to see.

Update. MP has commented that NOAA/NCDC also has a plot out. below is the graph that he linked, and below that is my graph, in similar colors (supplied by MP) which I showed in the previous post. It's of special interest because NCDC is using essentially the same global data combination (GHCNv3/ERSST).


  1. NCDC is also out, here is the map

    I've been experimenting with alternative colormaps and binning, I will get back to you on this.


  2. Thanks, MP
    I've linked in an update to the post.

    Incidentally, the "GISS" color scheme that I use is: