Climatological mean field
From Glossary of Meteorology
climatological mean field
A climatological field of a meteorological variable that has been averaged over a specified amount of time. For example, the climatological mean field of January air temperatures is a spatial expanse of monthly air temperatures that have been averaged at each field (or grid) point over a multiyear period of time.
Reference:
Seager, R., and Coauthors, 2007: Model projections of an imminent transition to a more arid climate in southwestern North America. Science, 316, 1181–1184, doi:10.1126/science.1139601.
term added 27 August 2014