Comments on: Tsonis and Teleconnections

By: Erl Happ

Erl Happ — Sat, 22 Nov 2008 07:53:55 +0000

At http://climatechange1.wordpress.com/ my latest description of the ENSO driver.What is increasingly apparent is that most of the action is between the equator and 30°S east of Tahiti. ENSO 3.4 looks increasingly like an artifact of something that happens elsewhere.

By: Bob Tisdale

Bob Tisdale — Wed, 12 Nov 2008 00:47:30 +0000

Erl: Here’s a link to a video from the NASA Scientific Visualization Studio titled “Visualizing El Nino”.
http://svs.gsfc.nasa.gov/vis/a000000/a000200/a000287/a000287.mpg
Hope it helps with this discussion. Sorry to jump in so late.

By: Erl Happ

Erl Happ — Sun, 09 Nov 2008 15:07:51 +0000

At http://bobtisdale.blogspot.com/ Bob Tisdale has some interesting observations re the way subsurface temperature change occurs before surface temperature change. Is this a light penetration factor? The surface exchanges energy with the atmosphere to some extent. The bodies of warm wet topical air that stream away from the equator keep the sea surface warm. To see this compare a SST anomaly map with Precipitable water like here: http://www.coaps.fsu.edu/~maue/extreme/gfs/current/plan_water_000.png.

If it is a light penetration factor, change must be related to albedo.

By: Paolo M.

Paolo M. — Sun, 09 Nov 2008 10:35:47 +0000

Re: David Smith (#172), what I know is that almost all of AOGCMs don't have something resembling the ENSO mode of natural variability. So I don't think that the heat content of Pacific water is forecasted in advance. Anyway, David, if you know some works assessing this issue, please let me know.

By: David Smith

David Smith — Sat, 08 Nov 2008 19:45:44 +0000

Re #171 Paolo, I think the short answer for the dynamical coupled models is “yes”, but I believe that their skill is modest, especially in boreal Spring.

By: Paolo M.

Paolo M. — Sat, 08 Nov 2008 17:09:14 +0000

Re: David Smith (#169),
what I meant was that the early signal of a new ENSO phase (if I understood well what I read long time ago) is an eastward travelling Kelvin wave along the thermocline. Are the dynamical models you talk about able to forecast the start and the strenght of a Kelvin wave some months in advance?
Whenever a Kelvin wave is in the initial analysis, I’m not surprised that a model can forecast its effect on the SST some months later.
But what about the forecast of the heat content of the deeper water?
I have no expertise in ENSO forecasts, but, at a first sight, models don’t seem to predict deep water behaviour some months in advance. However, I can very well be wrong.
The April barrier make me think of a sort of strong non linearities in the troposphere circulation at the end of the boreal winter that can overcome any initial state of water temperature anomalies in the Pacific.

By: Erl Happ

Erl Happ — Sat, 08 Nov 2008 14:45:01 +0000

Re: Leif Svalgaard (#166),
Leif,
Good to see you taking an interest in tropical warming events.

Look at the variation between the models and the way they flop around from week to week. I guess the modelers just can’t agree on the parameters that should be included and how to weight them.

Perhaps a meteorologist can answer the following question for us? What determines the flux of temperature at 200hPa in the Pacific near Peru and Chile and how does it affect cirrus cloud cover and the strength of the South East Trade winds between Tahiti (17°S Lat.) and Darwin (8° S Lat.).

I have another question. Why is there a very close parallel between the SOI (sign inverted) and global 200hPa temperatures between 10°-20° south latitude and in no such close parallel with other 10° latitude bands?

A bit of advertising: I have a post at http://climatechange1.wordpress.com that might be of interest in relation to greenhouse theory.

By: David Smith

David Smith — Sat, 08 Nov 2008 13:55:12 +0000

Re #168 Paolo, my understanding is that the dynamical ENSO models do have moderate skill at forecasting SST anomalies some months in advance, including changes in SST anomaly trend. Their abilities are poorest around the boreal Spring “persistence barrier”.

By: Paolo M.

Paolo M. — Sat, 08 Nov 2008 11:56:40 +0000

Re: David Smith (#167), ENSO models have some forecasting skill to do what? To forecast, anticipating, the early stage of a new ENSO phase or just to recognize that early stage and to persist with the new tendency?

By: David Smith

David Smith — Fri, 07 Nov 2008 21:01:08 +0000

Re #166 Hmmm… that would be a good question for Erl.

Most ENSO models have some forecasting skill. So, any solar/ENSO connection would likely involve the atmospheric parameters used by those models. If I was a solar/ENSO explorer I’d venture there.