"Decadal basis" refers to a period of ten years. It is used to measure or analyze something over a span of ten years.
Sentences with «decadal basis»
Of course, we know TOA fluxes must continue to warm globally on a decadal basis because we have OHC data. (realclimate.org)
It is also important to note that the models are not designed to project climate on a decadal basis, but on a centennial basis, where the effects of internal variability can more reasonably be expected to average out. (skepticalscience.com)
To keep those error outliers small, I tried to reconstruct the data to a decadal base line, which is still adequate and reduces error outliers, as you can see here in Fig. 1 (climateaudit.org)