ENSO Discussion

[Guest happ]

Warmer falls, cooler springs has been the tendency for most of the NH as well. 

 

There haven't been many cool springs in California for a long time [e.g. 2006]

[Phil]

Warmer falls, cooler springs has been the tendency for most of the NH as well.

Only for North America. The exact opposite has been true over much of Eurasia, which is also to be expected under the aforementioned boundary condition(s).

[Phil]

What sort of indices favor this?

Outside a coherent -ENSO..

 

1) A mod/strong -IOD (Indian Ocean Dipole).

 

2) A -PMM (Pacific Meridional Mode) during JJA (and obviously beyond as well).

 

3) A +QBO (dampens MJO propagation out of EHEM into the Pacific).

 

4) The 2nd half of solar minimum, and first 1-2yrs of next solar cycle upswing (slew of reasons for this, many involving system lags involving fluid-thermodynamic inertias).

[Phil]

Regarding the meridional mode(s), this fantastic paper by Chang/Zhang (et al, 2007) might be of interest to folks here given the implications for extended-range ENSO prediction. It's one of the methodologies I employ to forecast ENSO.

 

ftp://wxmaps.org/pub/lzhang/paper/2007_Chang_etal_GRL.pdf

[Front Ranger]

Only for North America. The exact opposite has been true over much of Eurasia, which is also to be expected under the aforementioned boundary condition(s).

 

Per GISS, falls in NH since 2005 have been running a .04C warmer anomaly than springs. 

[Phil]

Per GISS, falls in NH since 2005 have been running a .04C warmer anomaly than springs.

That's a result of GISS's infilling/extrapolation of anomalies across thousands of miles in the high latitude/Arctic domain, where there is no widespread surface station network. If you infill the missing areas on GISS with the available satellite data, this changes the result. There has been some extreme Arctic warmth during recent Autumns but generally this has been more confined to the subarctic territories.

 

I also don't know where you're getting these numbers from. I've looked at all these datasets already in years past, though, and the conclusion is pretty clear, in my opinion.

[Front Ranger]

That's a result of GISS's infilling/extrapolation of anomalies across thousands of miles in the high latitude/Arctic domain, where there is no widespread surface station network. If you infill the missing areas on GISS w/ the satellite data, this changes the results.

 

I also don't know where you're getting these numbers from. A source would be nice.

 

I told you. GISS: https://data.giss.nasa.gov/gistemp/maps/

[Phil]

I told you. GISS: https://data.giss.nasa.gov/gistemp/maps/

Okay, but my point still stands. It's an artificial anomaly.

 

Also, you can add/remove a single year and it erases your 0.04C differential. So it's a cherry-picked timescale anyway, in my opinion.

[Front Ranger]

Okay, but my point still stands. It's an artificial anomaly.

 

Also, you can add/remove a single year and it erases your 0.04C differential. So it's a cherry-picked timescale anyway, in my opinion.

 

It was just the first year I picked. Yeah, the differential varies based on the year you start with, but the overall trend (per GISS) is warmer falls than springs in the NH for the past 10-20 years.

[Phil]

It was just the first year I picked. Yeah, the differential varies based on the year you start with, but the overall trend (per GISS) is warmer falls than springs in the NH for the past 10-20 years.

Again, it's an artificial anomaly created by GISS's infilling and extrapolation procedure across thousands of square miles throughout the high latitudes. Replace the GISS extrapolations with real satellite data for the lower troposphere, and the result reverses (and then some).

 

So, I think your point is pointless. No offense.

[Phil]

Neither HADCRUT4 or any of the satellite datasets depict warmer boreal autumns across the NH, let alone the EHEM/Eurasia. Only the datasets that employ artificial extrapolatory procedures (GISS/NCDC) depict the autumnal NH warmth, and it's confined to locations above 70N.

[Front Ranger]

Again, it's an artificial anomaly created by GISS's infilling and extrapolation procedure across thousands of square miles throughout the high latitudes. Replace the GISS extrapolations with real satellite data for the lower troposphere, and the result reverses (and then some).

 

So, I think your point is pointless. No offense.

 

The Arctic has been very warm in the fall the past decade or so, though. There is a physical reason for that, because there has been more open water to freeze up, which then warms the atmosphere. So it's not just GISS extrapolation to blame.

[Phil]

The Arctic has been very warm in the fall the past decade or so, though. There is a physical reason for that, because there has been more open water to freeze up, which then warms the atmosphere. So it's not just GISS extrapolation to blame.

1) Sure, it's been warm. But GISS's extrapolation procedure overestimates the warmth, particularly over areas with healthy sea/land ice. All of the other datasets (that don't rely on such prolific extrapolation) paint a very different picture.

 

2) Open water has little to do with the Arctic warmth. If open water was responsible, then the warmest Arctic temperature anomalies would occur during summer (when the albedo effect is at its strongest), not the winter (when the high Arctic receives essentially zero insolation). The enhanced Arctic warmth is actually a result of increased advection of warm/moist air via enhancement of the off-equator WPAC convection (thanks to the poleward-shifted WPAC warm pool and Hadley Cell).

[Front Ranger]

1) Sure, it's been warm. But GISS's extrapolation procedure overestimates the warmth, particularly over areas with healthy sea/land ice. All of the other datasets (that don't rely on such prolific extrapolation) paint a very different picture.

 

2) Open water has little to do with the Arctic warmth. If open water was responsible, then the warmest Arctic temperature anomalies would occur during summer (when the albedo effect is at its strongest), not the winter (when the high Arctic receives essentially zero insolation). The enhanced Arctic warmth is actually a result of increased advection of warm/moist air via enhancement of the off-equator WPAC convection (thanks to the poleward-shifted WPAC warm pool and Hadley Cell).

 

The actual process of water freezing gives off excess heat energy: http://www.cmmap.org/news/articles/heatpack.pdf

 

Therefore, more open water going into fall means more water freezing, which means more heat going into the atmosphere in the Arctic.

[Jesse]

This thread should go back to being about tracking ENSO.

[Phil]

The actual process of water freezing gives off excess heat energy: http://www.cmmap.org/news/articles/heatpack.pdf

 

Therefore, more open water going into fall means more water freezing, which means more heat going into the atmosphere in the Arctic.

Yes, I'm aware of latent heat absorption/release. It's still not nearly enough to override albedo as a forcing on temperature, however. We're talking about a 1 to 10 joule ratio here at the very least.

[Phil]

Moderate Nino (ONI peak trimonthlies +1.0 to +1.4) looks like most likely outcome to me.

[Front Ranger]

Yup, that one is looking like a bust. Predicting ENSO has never been my strength. Maybe I should stick with predicting what happens with weather patterns - the (partial) and more tangible results of ENSO.

 

FWIW, I spent about 5 min of research before making that statement. A lot less than I put into seasonal forecasts.

[Geos]

 

Probably will be looking at a neutral winter or weak Nina with the way it's looking.

[Phil]

Probably will be looking at a neutral winter or weak Nina with the way it's looking.

As far as I'm concerned, we've been in a weak -ENSO circulation since June. The SSTAs are just responding to the wind stress/low degree coupling that's already been present.

 

The off-equator WPAC and IO haven't cooperated, though, so we've seen some alterations to the extratropical wavetrain.

[stuffradio]

As far as I'm concerned, we've been in a weak -ENSO circulation since June. The SSTAs are just responding to the wind stress/low degree coupling that's already been present.

 

The off-equator WPAC and IO haven't cooperated, though, so we've seen some alterations to the extratropical wavetrain.

The SOI hasn't been in a Nina state though, with the exception of a few days when it was in a raging Nina state.

[Phil]

The SOI hasn't been in a Nina state though, with the exception of a few days when it was in a raging Nina state.

Yeah, but that's mostly a result of the +IOD circulation. The SOI is simply a measure of a local pressure differential and IMO is an outdated method of analyzing ENSO's atmospheric component(s).

 

I prefer low-pass filtered VPs and 850/200 U-wind anomaly differentials, myself. Many others prefer OLR/SSTs and subsurface temps/currents, but I'm not a fan of utilizing those as measures of current low frequency atmospheric behaviors that would be associated w/ ENSO.

[Bryant]

3/4 ENSO regions now into Nina territory. Region 4 being the only exception 

[Bryant]

Big EWB about to begin. Cold subsurface waters ready to upwell

 

[Bryant]

After this upcoming EWB, SSTs may be the coldest we've seen since 2011

 

[Phil]

After this upcoming EWB, SSTs may be the coldest we've seen since 2011

 

Under an antecedent "Niña-esque" circulation, the -QBO appears to have played major role in consolidating the system into more of a true, coherent Niña state, I think. It beefed up the WPAC warm pool indirectly via forcing on the Indo-China convection and monsoon(s), which has dropped the PDO/PNA integral and produced the persistent trades/tight Walker Cell.

 

Something similar happened in 2007, albeit the EHEM and high latitudes were in a much different state.

[Phil]

I think that, while the -QBO is constructive to base state reconsolidation during boreal autumn, it becomes destructive during boreal winter as the waveguide conduits mature and feedbacks change.

[SilverFallsAndrew]

Looks like a moderate Nina is definitely still on the table!

[Geos]

Might need to change this to a Nina watch...

 

[stuffradio]

CFSv2 showing big E wind anomalies in mid-late September and Nino index 3 at its lowest point so far this summer.

 

[Geos]

Looks like a la Nina now for sure.

 

 

[Geos]

Can we say we have a La Nina already...

 

a

[crf450ish]

Anyone have a link depicting the comparison between the last (strong) Nina and this developing Nina at the same point in time in the year?

[Geos]

Anyone have a link depicting the comparison between the last (strong) Nina and this developing Nina at the same point in time in the year?

 

 

Stronger now.

[snow_wizard]

Wow!  The CFS is now showing a strong nina for this winter.  The biggest model bust on ENSO (refering to what was being shown a few months ago) that I've ever seen.  It's going to be interesting to see how this ends up playing out for this winter.  Right now we have a few things to consider.

 

1. 2nd cold ENDO winter in a row (often a very good thing)

2. Negative QBO (could result in an overpowering Pacific jet)

3. Very low solar activity (could offset effects of negative QBO).

 

At this point a lot of WNW or NW flow type stuff looks like a decent bet this winter.

[Front Ranger]

http://www.ospo.noaa.gov/data/sst/anomaly/2016/anomnight.9.5.2016.gif

 

Stronger now.

 

Last strong Nina would be 2010 though, not 2016.

[Geos]

Last strong Nina would be 2010 though, not 2016.

 

Oops

[Phil]

Wow! The CFS is now showing a strong nina for this winter. The biggest model bust on ENSO (refering to what was being shown a few months ago) that I've ever seen. It's going to be interesting to see how this ends up playing out for this winter. Right now we have a few things to consider.

 

1. 2nd cold ENDO winter in a row (often a very good thing)

2. Negative QBO (could result in an overpowering Pacific jet)

3. Very low solar activity (could offset effects of negative QBO).

 

At this point a lot of WNW or NW flow type stuff looks like a decent bet this winter.

FWIW, east-based -ENSO also drops the global temperature more efficiently since the IPWP/WPAC can ventilate more efficiently. That fact, in addition to a few other factors, should allow the global mean temperature to drop to its lowest level in at least five years this winter (or spring).

 

The battle between -QBO/+EPO and low solar/-NAM will be fascinating to watch. If the solar wind can slacken, then we could knock out the PV sooner, which would reverse the momentum deposition onto NAM and maybe flip the EPO.

 

If not, then it's another 2007/08.

[Phil]

We saw last winter why destroying the PV/NAM is necessary to maintain stable midwinter NPAC blocks.

 

Ideally, you actually want a hostile NPAC (+PNA/+WPO) during November/December which opens the conduits to poleward transfer and takes out the PV, which then allows NPAC anticyclones to amplify and sustain without getting mowed down by the westerlies.

[Guest happ]

Last strong Nina would be 2010 though, not 2016.

 

Yes 2010 produced 22.73" followed by 32.88 inches in 2011. Some La Nina's can be very beneficial for rain and cooler than average temps in California.