CyclonicFury wrote:USTropics wrote:aspen wrote:How do +/-IODs impact Atlantic hurricane season activity? In this situation, would a +IOD help or hamper MDR activity?
There is some debate over the connection between IOD and ENSO, but essentially the +/- mode of the IOD can hinder or propel atmospheric changes during ENSO transitions. For instance, a + IOD increases Pacific trade winds, promotes La Nina, and strengthens the Walker circulation. A - IOD creates weaker trade winds, promotes El Nino, and weakens the Walker circulation. So basically the chain is:
positive IOD --> cooling ENSO (La Nina) --> enhanced Walker circulation --> more active Atlantic
negative IOD --> warming ENSO (El Nino) --> weakened Walker circulation --> less active Atlantic
I thought it was the other way around, doesn't a -IOD favor upward motion over the Maritime Continent, which is more La Niña like, while a +IOD favors sinking over this region?
Eventually it does, but there's essentially a cycle it must complete:
Compare circulations here as well:
Again want to iterate the beginning of my post, there is some debate over the connection between IOD and ENSO. Research on the IOD is still in its infancy so to speak (discovered about ~25 years ago). Its true connection is still unknown, but this research article (https://commons.lib.niu.edu/bitstream/1 ... _12302.pdf) does a good job of describing the different teleconnections.
