Lucia beat me to a post on this, so I’ll give her the honor here. Interesting thing though, the delay of Hadley may have provided a better data presentation. – Anthony
Guest Post by Lucia from The Blackboard
Guess what? The much anticipated Hadley monthly surface temperature anomalies are now available. I always use the NH+SH simple average.
Guess what else? According to this metric, the global surface temperature anomaly September 2009 cooled relative to August 2009 dropping from0.548C to 0.457C. In contrast, GISSTemp, NOAA/NCDC, UAH and RSS all reported distinctly warmer anomalies in September relative to August. This divergence is a pit surprising– though I’d have to plough through numbers to see if this sort of mismatch is unprecedented in the record.
One of the interesting happenings this month was Hadley’s decision to delay processing because they considered the some data they received to be obviously wrong. We don’t have details on precisely what was wrong about it, but I noticed large blanked out areas on their map:
The blanked out areas do seem to be surrounded by warm regions. Maybe the computed value for September’s monthly average will rise when that region reports data Hadley trusts. In the meantime, Hadley’s September temperature is low relative to the other metrics.
Since we anticipate October temperature will be reported soon, and I suspect some revisions for September, I’ll just show the trends based on reported temperatures since both 2000 and 2001, and also compare them anomalies to the multi-model mean anomalies from the AR4 climate models driven by the A1B SRES.
As you can see, EL Nino has caused temperatures to rise; the anomalies for individual months values are currently approaching the mean value projected by the models. As El Nino warms further, the observations for individual months may finally catch and surpass the models, as the do from time to time. However, it’s going to take sustained warming for the trends since either 2001 or 2000 to catch up with the projections. Will it happen? We’ll wait and see.
I left this comment on Lucia’s thread, which I will repeat here:
Lucia, I don’t think this is anything out of the ordinary to have so may data holes. Look at GISS for September:
Link to original at GISS is here
The trend of missing stations in GHCN continues. It appears that Hadley actually has more stations than GISS. Maybe the delay was to allow more trickle in of late reporters. – Anthony