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#1481901 - 20/12/2018 20:35 Re: Climate Driver Discussion 2018 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
Kino Offline
Weatherzone Addict

Registered: 10/08/2017
Posts: 3505
Loc: Wollongong, NSW, Aus
And I notice that they are closer to NZ whereas the current warmth is much closer to Aus?

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#1481920 - 20/12/2018 23:24 Re: Climate Driver Discussion 2018 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
Eigerwand Offline
Weather Freak

Registered: 28/05/2012
Posts: 526
removing content


Edited by Mick10 (21/12/2018 17:22)

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#1481936 - 21/12/2018 07:20 Re: Climate Driver Discussion 2018 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
Mike Hauber Offline
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Registered: 13/07/2007
Posts: 3817
Loc: Buderim
A comparison of the atmospheric response to several borderline el nino events. First 2006 was declared el nino by both BOM and NOAA and is clearly an el nino, but weakest event in recent years. Second 2004 and 2014 were both declared el nino by NOAA, but not by BOM. Both experienced extended periods aboe 0.5 for nino 3.4, enough to meet NOAA threshold, but 2004 did not reach 0.8, and 2014 only for one month, so not enough to meet the BOM threshold.

First for trade winds, 2018 has a similar trade wind response to 2006. The peak westerlies are a little weaker, the stronger westerlies along the equator are a little further west, westerlies to the north of the equator are stronger, and the area of weakly above average trades in 2006 was more extensive. Keep in mind that 2018 is missing data in the west, and I assume that the stronger westerly anomalies extended at least part of the way into this area of missing data. If we compare to the NOAA but not BOM el nino years of 2004 and 2014 we see that the westerly anomalies are substantially stronger.









For cloudiness the shift of tropical convection away from the area north of Australia towards the east is weaker than both 2006 and 2004, but still comparable (in my opinion slightly stronger) to 2014.

2018:


2014:


2006:


2004:


The atmospheric response for cloudiness and trade winds is quite similar to other recent near threshold events, and it is only SOI showing an unusual response. SOI can be an erratic measure and is not measured near the equator where key ENSO processes occur. Cloudiness and trade wind response are the two key atmospheric indicators that can have a direct influence on SSTs. A comparison to weaker warm neutral years such as 2001, 2003 and 2012 shows a clear difference with those years all having a weaker atmospheric response than any of the years shown.

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#1481961 - 21/12/2018 10:12 Re: Climate Driver Discussion 2018 (Enso, IOD, PDO ,SAM etc) [Re: Mike Hauber]
ColdFront Offline
Meteorological Motor Mouth

Registered: 29/06/2008
Posts: 19046
Loc: The Beach.
Originally Posted By: Mike Hauber
SOI can be an erratic measure and is not measured near the equator where key ENSO processes occur.


Except it hasn't been erratic this past few months where it has trended away from ElNino levels. In fact December looks like being positive also like the preceding two months and the current 30 day measure is above LaNina level (Currently the 30 day is +8.53)

NOAA seem fairly adamant that we will go into an official event next month which would be unprecedented. I think personally that the world's climate experts are baffled by this year due to the warm equatorial waters extending well beyond conventional ElNino realms. Perhaps they'll call it just to put it to bed despite the obvious fact the Indian Ocean is doing the heavy lifting.

_________________________


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#1481967 - 21/12/2018 11:08 Re: Climate Driver Discussion 2018 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
Mike Hauber Offline
Weatherzone Addict

Registered: 13/07/2007
Posts: 3817
Loc: Buderim
SOI looks erratic to me. This year it has switched from -ve to +ve 11 times.



Compare to nino 4 - which has had a clear trend all year in the same direction, with noise going against this trend limited to maybe 5 or 6 weeks at most.



And while warm SSTs in the Coral sea might be interesting, there were also warm SSTs in the coral sea during 1997 and 2004

Warm SSTs to the north of Australia are typical in an el nino at this time of year.

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#1481968 - 21/12/2018 11:09 Re: Climate Driver Discussion 2018 (Enso, IOD, PDO ,SAM etc) [Re: Mike Hauber]
Kino Offline
Weatherzone Addict

Registered: 10/08/2017
Posts: 3505
Loc: Wollongong, NSW, Aus
Originally Posted By: Mike Hauber
A comparison of the atmospheric response to several borderline el nino events. First 2006 was declared el nino by both BOM and NOAA and is clearly an el nino, but weakest event in recent years. Second 2004 and 2014 were both declared el nino by NOAA, but not by BOM. Both experienced extended periods aboe 0.5 for nino 3.4, enough to meet NOAA threshold, but 2004 did not reach 0.8, and 2014 only for one month, so not enough to meet the BOM threshold.

First for trade winds, 2018 has a similar trade wind response to 2006. The peak westerlies are a little weaker, the stronger westerlies along the equator are a little further west, westerlies to the north of the equator are stronger, and the area of weakly above average trades in 2006 was more extensive. Keep in mind that 2018 is missing data in the west, and I assume that the stronger westerly anomalies extended at least part of the way into this area of missing data. If we compare to the NOAA but not BOM el nino years of 2004 and 2014 we see that the westerly anomalies are substantially stronger.









For cloudiness the shift of tropical convection away from the area north of Australia towards the east is weaker than both 2006 and 2004, but still comparable (in my opinion slightly stronger) to 2014.

2018:


2014:


2006:


2004:


Well for starters your comparison is broken as for some reason all your historical maps are 1/9 - 30/11 whereas this year you start 20/9 and finish 19/12.

2004 & 2006 seem to be a good match for OLR anomalies but nothing like 2018 - so that's a miss. 2018 has no OLR anomalies for Aus continent at all.

2014 seems more comparable except there are no +anomalies on the Aus continent and the Tasman seen +anomalies are focused on NZ.

Originally Posted By: Mike
The atmospheric response for cloudiness and trade winds is quite similar to other recent near threshold events, and it is only SOI showing an unusual response. SOI can be an erratic measure and is not measured near the equator where key ENSO processes occur. Cloudiness and trade wind response are the two key atmospheric indicators that can have a direct influence on SSTs. A comparison to weaker warm neutral years such as 2001, 2003 and 2012 shows a clear difference with those years all having a weaker atmospheric response than any of the years shown.


Nonense. As outlined, the only weak similarity is 2014 and again it's main similarity is SE Asia.

As for the statement about SOI - that shows no understanding of Hadley Cells and their roles in ENSO. Post all the graphs you like but when you make statements like this they have to be challenged. Each cell encircles the globe latitudinally and acts to transport energy from the equator to about the 30th latitude. The teleconnections and latitudinal variation of Hadley Cells are the reason the SOI is measured in Darwin and Tahiti, ergo if their respective pressures are anomalous then it is clear evidence of coupling or the opposite. You keep repeating this nonsense every single post, trying to re-write atmospheric circulation rules, but it doesn't make it true.

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#1481969 - 21/12/2018 11:18 Re: Climate Driver Discussion 2018 (Enso, IOD, PDO ,SAM etc) [Re: Mike Hauber]
Kino Offline
Weatherzone Addict

Registered: 10/08/2017
Posts: 3505
Loc: Wollongong, NSW, Aus
Originally Posted By: Mike Hauber
SOI looks erratic to me. This year it has switched from -ve to +ve 11 times.



Compare to nino 4 - which has had a clear trend all year in the same direction, with noise going against this trend limited to maybe 5 or 6 weeks at most.



So, because SOI doesn't fit within a certain point of view it's "erratic" but SST's are "noise". Disingenuous.

Jan 2018 SST anomalies start negative and don't hit 0 til May 2018 - that's clearly not 'noise'? And haven't SST's been acknowledged time, and time again by everyone. Yes, they've hit El Nino levels but all the other indicators haven't.

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#1481970 - 21/12/2018 11:20 Re: Climate Driver Discussion 2018 (Enso, IOD, PDO ,SAM etc) [Re: Kino]
Mike Hauber Offline
Weatherzone Addict

Registered: 13/07/2007
Posts: 3817
Loc: Buderim
Originally Posted By: Kino


Nonense. As outlined, the only weak similarity is 2014 and again it's main similarity is SE Asia.


The prime action in ENSO is moving convection along the equator away from PNG/Indonesia and out into the Pacific. This is exactly what we see. Impacts on Austrlia and South East Asia are secondary impacts, and will vary according to subtropical influences etc.

Originally Posted By: Kino
As for the statement about SOI - that shows no understanding of Hadley Cells and their roles in ENSO.


The Hadley Cells have no signficant role in el nino.

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#1481971 - 21/12/2018 11:23 Re: Climate Driver Discussion 2018 (Enso, IOD, PDO ,SAM etc) [Re: Kino]
Mike Hauber Offline
Weatherzone Addict

Registered: 13/07/2007
Posts: 3817
Loc: Buderim
Originally Posted By: Kino


So, because SOI doesn't fit within a certain point of view it's "erratic" but SST's are "noise". Disingenuous.

Jan 2018 SST anomalies start negative and don't hit 0 til May 2018 - that's clearly not 'noise'? And haven't SST's been acknowledged time, and time again by everyone. Yes, they've hit El Nino levels but all the other indicators haven't.


I'm showing the difference between an erratic and less erratic measure.

The only indicator that hasn't hit el nino level is SOI. Other indicators have no defined el nino level, and as I've just shown look pretty similar to past borderline el nino events.

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#1481975 - 21/12/2018 12:04 Re: Climate Driver Discussion 2018 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
ashestoashes Offline
Weather Freak

Registered: 22/10/2017
Posts: 739
Loc: Voyager Point (South West Sydn...
I would say that SOI has been so erratic due to the atmosphere and the ocean not coupling. Hence it moves on the whims of weather events.

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#1481976 - 21/12/2018 12:05 Re: Climate Driver Discussion 2018 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
ColdFront Offline
Meteorological Motor Mouth

Registered: 29/06/2008
Posts: 19046
Loc: The Beach.
The reason it hasn't hit ENSO levels has been due to lack of coupling and most likely due to the fact that warming extends well beyond ElNino boundaries though BoM and NOAA are at a loss as to why also. BoM use a 90 day centre for a reason . It smooths erratic readings over shorter time frames and that 90 day centre is actually positive.


Originally Posted By: Mike Hauber


The only indicator that hasn't hit el nino level is SOI. Other indicators have no defined el nino level


That's right, they use logic and preceded observation instead.
_________________________


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#1481977 - 21/12/2018 12:07 Re: Climate Driver Discussion 2018 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
Petros Offline
Meteorological Motor Mouth

Registered: 30/12/2002
Posts: 8071
Loc: Maffra, Central Gippsland, Vi...
Just had a peruse around the EQ Pacific Ocean metrics,

* SST profile is still the same as is has been for past 60 days
* no tropical cloud systems evident across Nino3.4 by latest SatIR
* trade winds continue to blow freshly from Nino1.2 through well into Nino.4 acc. to Windy
* there is no SSL anomaly through all Nino zones
* MJO has arrived above Aus, and is set up to camp there for the next 7-14 days
* Recent cyclone has created little, if any, cooling of SST in Gulf of Carpenteria
* SOI index is now strongly positive

I conclude we have neutral Nino conditions, despite the Pacific ocean, as a whole, being slightly warmer (0.5 to 1 degC) than it was compared to its average temp over the period 1981-2010 (when will an alternative data set be chosen?).

So I conclude we should experience typical (ie, non-Nino, non-Nina) seasonal conditions over the Aus tropics for next 2 weeks, ....also the door is open for tropical moisture to advect into Aus southern regions should sub-tropical weather systems dictate.

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#1481979 - 21/12/2018 12:10 Re: Climate Driver Discussion 2018 (Enso, IOD, PDO ,SAM etc) [Re: ashestoashes]
Mike Hauber Offline
Weatherzone Addict

Registered: 13/07/2007
Posts: 3817
Loc: Buderim
Originally Posted By: ashestoashes
I would say that SOI has been so erratic due to the atmosphere and the ocean not coupling. Hence it moves on the whims of weather events.


Ocean is not driving SOI. But Ocean is driving trade winds and cloudiness changes similar to past el ninos. These changes are enough to sustain persistent warming. Therefore SOI is not part of coupling.

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#1481980 - 21/12/2018 12:13 Re: Climate Driver Discussion 2018 (Enso, IOD, PDO ,SAM etc) [Re: Petros]
Mike Hauber Offline
Weatherzone Addict

Registered: 13/07/2007
Posts: 3817
Loc: Buderim
Originally Posted By: Petros
Just had a peruse around the EQ Pacific Ocean metrics,

* SST profile is still the same as is has been for past 60 days
* no tropical cloud systems evident across Nino3.4 by latest SatIR
* trade winds continue to blow freshly from Nino1.2 through well into Nino.4 acc. to Windy
* there is no SSL anomaly through all Nino zones
* MJO has arrived above Aus, and is set up to camp there for the next 7-14 days
* Recent cyclone has created little, if any, cooling of SST in Gulf of Carpenteria
* SOI index is now strongly positive



*No tropical cloud systems over nino 3.4 in past borderline el ninos. Cloud is further west near the dateline.
*Trade winds for the last few days, and forecast for the next few days are near normal to a little above normal. Substantial westerly anomalies are forecast to return and have dominated the last few months.
*Sea level has been substantially higher than normal through all nino zones.

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#1481985 - 21/12/2018 12:35 Re: Climate Driver Discussion 2018 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
Petros Offline
Meteorological Motor Mouth

Registered: 30/12/2002
Posts: 8071
Loc: Maffra, Central Gippsland, Vi...
Thanks Mike, for me, cloud nearer the dateline signifies neutral (normal) ESNO state.
SSL is equally high across the Pacific, if it was stacked up over the eastern side, that would indicate El Nino (or a build towards one) to me. With no difference in SSL (remembering this is only a level anomaly) right across the EQ Pacific, this would signify neither Nino or Nina to me.

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#1481986 - 21/12/2018 12:39 Re: Climate Driver Discussion 2018 (Enso, IOD, PDO ,SAM etc) [Re: Mike Hauber]
Kino Offline
Weatherzone Addict

Registered: 10/08/2017
Posts: 3505
Loc: Wollongong, NSW, Aus
Originally Posted By: Mike Hauber
Originally Posted By: Kino
As for the statement about SOI - that shows no understanding of Hadley Cells and their roles in ENSO.


The Hadley Cells have no signficant role in el nino.


Quote:
Abstract
The interannual variability of the boreal winter Hadley circulation extents during the period of 1979–2014 and its links to El Niño-Southern Oscillation (ENSO) were investigated by using reanalysis datasets. Results showed that the El Niño (La Niña) events can induce the shrinking (expansion) of Hadley circulation extent in the Southern Hemisphere. For the Northern Hemisphere, El Niño (La Niña) mainly leads to shrinking (expansion) of the Hadley circulation extent in the middle and lower troposphere and expansion (shrinking) of the Hadley circulation extent in the upper troposphere. The ENSO associated meridional temperature gradients have close relationship with the Hadley circulation extents in both Hemispheres. But in the Northern Hemisphere, the ENSO associated eddy momentum flux divergence plays more important role in affecting the Hadley circulation extent than the meridional temperature gradient because of the small local Rossby number. In the Southern Hemisphere, as the ENSO induced eddy momentum flux divergence is small, the meridional temperature gradient dominates the change of the Hadley circulation extent.


From https://www.sciencedirect.com/science/article/pii/S1674927816300193

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#1481987 - 21/12/2018 12:46 Re: Climate Driver Discussion 2018 (Enso, IOD, PDO ,SAM etc) [Re: Petros]
Kino Offline
Weatherzone Addict

Registered: 10/08/2017
Posts: 3505
Loc: Wollongong, NSW, Aus
Originally Posted By: Petros
Thanks Mike, for me, cloud nearer the dateline signifies neutral (normal) ESNO state.
SSL is equally high across the Pacific, if it was stacked up over the eastern side, that would indicate El Nino (or a build towards one) to me. With no difference in SSL (remembering this is only a level anomaly) right across the EQ Pacific, this would signify neither Nino or Nina to me.
Originally Posted By: Petros
Thanks Mike, for me, cloud nearer the dateline signifies neutral (normal) ESNO state.
SSL is equally high across the Pacific, if it was stacked up over the eastern side, that would indicate El Nino (or a build towards one) to me. With no difference in SSL (remembering this is only a level anomaly) right across the EQ Pacific, this would signify neither Nino or Nina to me.


In fact it's highest in 3.4, and lower in 4. This removes any Modoki argument.


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#1481988 - 21/12/2018 12:51 Re: Climate Driver Discussion 2018 (Enso, IOD, PDO ,SAM etc) [Re: Kino]
Mike Hauber Offline
Weatherzone Addict

Registered: 13/07/2007
Posts: 3817
Loc: Buderim


That shows that ENSO affect Hadley. Says nothing about Hadley affecting ENSO.

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#1481989 - 21/12/2018 12:52 Re: Climate Driver Discussion 2018 (Enso, IOD, PDO ,SAM etc) [Re: Kino]
Mike Hauber Offline
Weatherzone Addict

Registered: 13/07/2007
Posts: 3817
Loc: Buderim
Originally Posted By: Kino


In fact it's highest in 3.4, and lower in 4. This removes any Modoki argument.



Definition of modoki never refers to sea level. Has nothing to do with any Modoki argument.

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#1481990 - 21/12/2018 12:57 Re: Climate Driver Discussion 2018 (Enso, IOD, PDO ,SAM etc) [Re: ColdFront]
Kino Offline
Weatherzone Addict

Registered: 10/08/2017
Posts: 3505
Loc: Wollongong, NSW, Aus
And neither does El Nino, Mike - you cannot have it both ways:

Originally Posted By: JAMSTEC
El Niño Modoki is a coupled ocean-atmosphere phenomenon in the tropical Pacific. It is different from another coupled phenomenon in the tropical Pacific namely, El Niño. Conventional El Niño is characterized by strong anomalous warming in the eastern equatorial Pacific (see figure below). Whereas, El Niño Modoki is associated with strong anomalous warming in the central tropical Pacific and cooling in the eastern and western tropical Pacific (see figure below). Associated with this distinct warming and cooling patterns the teleconnections are very different from teleconnection patterns of the conventional El Niño. Hence, the new phenomenon is of interest to the climate community.




But clearly anomalous SSL are directly relatable to ENSO conditions.

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