Is there a word that means (ac)cumulation over time?

I’m looking for a word that means (ac)cumulation over time. The time aspect is important. I looked around National Geographic articles on ice sheet formation hoping that I would stumble on a suitable word, but didn’t.

I'm trying to think of a more succint publication title. My current (and somewhat wordy) version is

"A Time-series Accumulation Approach to Soil Moisture Retrieval".

I was looking for an adjective to replace the "time-series accumulation" part.