PSD Gridded Climatology Changes
NOAA/NCDC has produced new "normals" or climatologies for many of their datasets and they plan on updating the rest when they are able to. These normals use data from 1981-2010 which replaces the old normals that used 1971-2000. We are changing our long term means to match this new climatology whenever it makes sense to do so. In some cases, we can't do the full 1981-2010 time period but we will do as much as is available.
This will impact both the climatologies as well as any anomalies that use the new climatologies. There are many changes but the most noticeable is that air temperature anomalies will tend to decrease over much of the world as temperature has generally increased since the the 1970's. See the NCDC normals webpage for details and answers to many questions.
We will make available the old climatologies for a period of time. Files will have the filenames var.timeperiod.yyyy-yyyy.ltm.nc. The current climatology (what will be 1981-2010) will be linked from the files var.timeperiod.ltm.nc