At first these NetCDF files with extensions like .nc and .cdf were a bit of a mystery to me. These files won't open in everyday programs I'm used to like Excel or text editors. But I'm making progress manipulating them in Matlab.
A website I often refer to for OLR graphs is Ole Humlum's Climate4You.com's temperature page here (excerpt with just the OLR graphs here).
But I guess that page needs to be manually updated and was last updated 2011; the data stops around 2010. Here's the first OLR graph from that page with global coverage using NOAA satellites that started measuring in June 1974:
I can now make similar graphs myself (from the data here) and so can add about three years to it to take it to about the year 2013. I'm using the above scale on the left of the graph below, but the scale on my graph is about 17 W/m2 less (right).
It shows a bit of a drop in OLR from 2010 to 2013, but nothing that remarkable. No real evidence of CO2 "heat-trapping" or correlation to CO2 to be seen in the above.
There should be a kind of inverse correlation between OLR and rising CO2 if heat-trapping from CO2 really was occurring. Clearly, from the above evidence alone, CO2 has no significant warming power in the atmosphere at all.
That graph I posted in the last blog post is of upward longwave radiation flux at nominal top of atmosphere (NTAT). I'm not sure the difference of NTAT from OLR at this point in time, but the graphs are different from each other.
I'm glad I was able to (sort of) duplicate Ole Humlum's graph as it indicates I'm on the right track to using functions like sum and squeeze. But still a bit of a mystery. I need to figure out how to do that red line average next.