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knocker

How do we know when the Madden Julian Oscillation is actually impacting mid-latitude circulation?

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This should ring a few bells.

 

 

While our knowledge pool continues to expand regarding the global-scale impacts of strong Madden Julian Oscillation (MJO) events, we still struggle as a community understanding the processes that often lead to these impacts. For example, forecasters too often overuse the MJO as a reason to explain why a particular state is being observed over a region solely based off the current and projected "phase" of an empirical orthogonal function (EOF) based MJO index without any physical explanation of why this state may be evolving. We often get consumed by the "black box" of the MJO phase space-diagram and simply just attribute causation rather than pin-point the underlying driving mechanism. So how can we tell if the MJO is actually playing a role on modulating extra-tropical circulation? What are tell-tale signatures that a forecaster can identify that shows the MJO is actually forcing a high-latitude response that can result in an arctic air mass intrusion over the U.S.? This study will aim to isolate key features that could bridge some of the gap between the tropical-extratropical climate interface.

 

https://ams.confex.com/ams/95Annual/webprogram/Paper260723.html

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Thanks for that link Knocker, i really enjoyed watching that.

 

Some of it still goes over my head as im still very much learning, but it certainly reminds me about the model thread over the winter where we were constantly looking at the MJO going into the COD before making it into a favourable phase for the UK in terms of cold.

 

Very interesting to learn then that we cant now dismiss cold outbreaks just because it doesnt make it to 7 & 8 as the video clearly shows evidence that once the MJO kicks off to a certain degree it seems to start a chain reaction even if it then tapers off.

 

Quite annoying though, as the USA did obviously get the jackpot this year, so they managed to complete the jigsaw but we did not. What affects up stream does affect us in Europe down stream. I guess we need a study for the MJO and Europe as whats true for the findings in that video for the US, dont look to be as certain for us. IF they were then shouldnt we have seen more scandi and greenland blocking if the atmosphere was acting as if the MJO had reached 7 or 8?


Very interesting stuff anyway :)

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