This image shows the land areas in black and has color codes for SSTAs, ranging from -5 to + 5 C. The yellow – orange color range shows positive anomalies while the blue – purple range show negative anomalies.
Many climate data sites show these NOAA images. Lucia at Blackboard, for example, compared Oct, Nov and Dec 2007 and 2008 by displaying an image montage.
Lucia said “..
“I have to admit I always have trouble integrating color images to estimate whether the net effect is a positive or negative anomaly. But, it is fun to look at the images…”
I have the same problem. While the images are great for giving the reader a sense for the spatial distribution of SSTAs, it sure would be nice to be able to evaluate the anomalies in a defined areas like NINO34 or even better to specify an area and see the trend over time!
There’s a free tool that I think is great for that!