Here are the maps of UAH, RSS and GISS (250 and 1200 radius) for July 2011 with the same base periodhttp://img823.imageshack.us/img823/310/uahrssgissjuly2011.pngAction seems to be at the poles, so coverage probably matters. Also interesting to see the tropics and some regions above oceans are warmer for UAH and RSS.MP
Thanks, MPI'll write a new post with this comparison. If you want to write something on what you have done, I would be very happy to post it here.
Of course, it doesn't mean much for the July anomaly to be "0.09 up" on June. If temperatures were linearly increasing from 1979 with no noise, then the July anomaly would be exactly the same as the June anomaly. All months of a given year would share the same anomaly. The month to month anomaly is mostly noise with possibly some change in the seasonal cycle.
drj,Yes, that's an artefact of the fixing of anomaly periods in a calendar year. But it also means that there would be a sudden change in anomaly every January, expressing the whole year's change.One could work out an anolaly base that avoided that. If m=0:11 are months, and y=0:30 are years after 1950, say, and T(m,y) is the temp,then the base for month i issum(T(i,0:29))(i-1)/360+sum(T(i,1:30))*(12-i)/360That would smooth it out.