India, Dec. 14 -- Think about what you know about how a monsoon system works: moisture evaporates from the oceans; it accumulates in the air; wind and weather systems move this accumulated moisture; pressure systems and heat cause it to rain. Traditionally, this has been seen as a rather smooth and gradual process. So far, so familiar. Except now, it turns out that the air itself has memory, of a kind. And that memory exists in the form of moisture or water vapour that can persist far longer than was previously thought - and exist and persist entirely independent of the oceans. This "memory" can impact a monsoon system in ways that are entirely independent of the monsoon system too. It can even serve as a tipping point, precipitating downpo...