Here's a comment I made on an ENSO blog @ weatherunderground in response to another blogger which is worth looking @ in regards to the recent SOI debacle, MJO, & historical precedence in terms of ENSO...
Blogger: "Also, I have a possibly crazy theory on what's happening with the SOI. In the last few frames of this animation, you can see what appears to be a smallish downwelling kelvin wave at the eastern edge of the Indian Ocean.
http://www.cpc.ncep.noaa.gov/products/G ... emp.0n.gifAnd on these maps you might notice increasing warm anomalies in the waters around central Indonesia/Northern Australia.
http://www.tropicaltidbits.com/analysis ... obal_1.png http://www.tropicaltidbits.com/analysis ... obal_1.pngThis would seem to indicate that the kelvin wave mentioned above is transporting heat from the eastern Indian Ocean to the area just north of Darwin. And with Tahiti being in the Nino 4 region, nowhere near where the much bigger.more instense Pacific kelvin wave is surfacing, it makes sense for the SOI to be increasing, at least until the heating in Nino 1 2 starts to spread westward."
Me: "I agree with this & think that the backside of the MJO pulse initially excited by Equatorial Convectively coupled (Atmospheric) Kelvin Wave activity that emanated from South America & into the eastern Indian Ocean where it triggered an MJO pulse near the end of March.
http://www.bom.gov.au/climate/mjo/graph ... .small.gifThis MJO pulse progressed through the Indian Ocean, & on the backside of the mean convective center, a series of very formidable WWBs likely was the cause for this downwelling Kelvin Wave as the westerly winds that pushed well into the Maritime Continent forced a piling up of water on the western side of the Maritime Continent. Also as you mentioned, this downwelling Kelvin Wave has led to an increase in SST surrounding Australia that is feeding back to an anomalous strong (@ least for preceding El Ninos) +SOI, however the SOI is highly susceptible to local weather, "noise" in the global tropics from (MRG, Eq Rossby, Intertio-Gravity waves. etc) & like another often mentioned oscillation in relation to ENSO (PDO), the SOI tends to lag changes in SST & other conditions associated with ENSO, not necessarily enforce them, although one could argue it does <em>exaggerate</em> them. I've looked into RMM MJO record since 1974 to at least attempt to find some historical precedence for this recent MJO debacle. I focused my attention on the January-June period preceding all first year El Nino events since 1974 that featured a decent amplitude (1.5 sigma or greater) MJO pulse that was able to for the most part, maintain or heighten this amplitude as the MJO pushed through the western Indian Ocean & into the Maritime Continent (Phases 3, 4 AND 5) & continued to withhold from going into the COD before generally reaching the western Pacific (phase 6) region like what has just transpired. What I discovered was that the MJO exhibited this behavior in preceding all El Nino events with exception to the 1982-83 & 1991-92 El Ninos, which I find interesting given these were the two El Nino events that coincided & followed some of the most of the largest volcanic eruptions within the last several decades (El Chichon 1982, Pinatubo 1991) (possibly significant influence on the OLR Principal Component (PC) of the MJO with major volcanic eruptions?).
Furthermore, I organized these events by the month & week in which they occur, & looking @ only events in which this MJO behavior was exhibited before May 1 (reason being, this is the period in which the Pacific is most vulnerable to WWBs, MJO activity, & for many El Ninos, is a crucial time for determining the intensity of the downwelling phase of the Eq KW that can reveal or at least hint @ even several months in advance, the intensity of the oncoming El Nino. Also the propagation speed of an Equatorial Kelvin Wave near 2.5-3 m/s means it typically takes about 3 months or so from the initiation of the disturbance in the western Pacific to the time it surfaces along with the western coast of South America, thus this indicates that if any forcing mechanisms, WWBs, Rossby Waves, etc, need to occur in the several months leading up to the initiation & evolution of an El Nino event, most preferably in spring when the Pacific is most susceptible to such anomalies in behavior.), I noticed something quite interesting...
2nd Week of Apr 1977-78 (Weak El Nino)
<img
http://www.bom.gov.au/climate/mjo/graph ... .small.gif 2nd Week of Feb 1994-95 (Weak El Nino)
http://www.bom.gov.au/climate/mjo/graph ... .small.gif1st Week of Feb 2004-05 (Weak El Nino)
http://www.bom.gov.au/climate/mjo/graph ... .small.gif2nd Week of Apr 2009-10 (Moderate El Nino)
http://www.bom.gov.au/climate/mjo/graph ... .small.gifWhile the sample size in this analysis is small, this implies at least from a historical standpoint that the recent tendencies of the MJO is quite atypical to that of strong El Ninos, in fact, if anything, we are seeing a more analogous pattern to that of weak El Ninos, but this isn't likely to remain this way for long.
Although its certainly not out of the ordinary for the MJO to enter the Indian Ocean, it certainly is discouraged to have strong amplitude in the Maritime Continent. This makes sense given the natural tendency for a progressively weaker Walker Cell in light of an oncoming El Nino. This consequently leads to the convective signal of the MJO to naturally push farther east into the Pacific & drop its spectral peak towards the lower end of the highly variable & "climatological" 30-90 day return period thanks to a decrease in global convective activity that is one of the primary drivers of the MJO's propagation through the global tropics. Hence, its common for the MJO to move much faster, w/ larger variations in amplitude through the tropics preceding El Nino, while the opposite tends to be the case in patterns before La Ninas."
Webbweather53,welcome to Storm2k. Don't hesitate to post all the stuff you post in other forums here as they are very helpful to the discussion of the different topics that we have here.
There's still something (or a lot of things) we don't know, IMO. I love watching this stuff.
