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Thursday, June 10, 2010

La Niña Is Not The Opposite Of El Niño – The Videos

I’ve moved to WordPress.  This post can now be found at La Niña Is Not The Opposite Of El Niño – The Videos
Weather noise and seasonal variability have stifled my previous attempts to animate noisy datasets like TLT anomalies. That noise made it difficult, at best, to determine what is taking place. A short example of a .gif animation of monthly TLT anomaly maps is shown in Figure 1.

Figure 1 – Sample Animation – Not Used In Video

Recently, I began animating maps that represent 12-month averages of “noisy” datasets with good results. The weather noise and seasonal variations are gone, for the most part. The 12-month-averaged TLT anomaly maps present a much “smoother” animation, as shown in the .gif sample, Figure 2.
Figure 2 – Sample Of Animation Used In Video

In the video, I liken the effect to smoothing the data in a time-series graph with a 12-month filter, Figure 3.
Figure 3 – Smoothed Time-Series Graph

The following 2-part video series provides detailed descriptions, time-series graphs, and animations of the processes that take place during El Niño and La Niña events. It uses TLT, SST, Total Cloud Amount, Sea Level, and Downward Shortwave Radiation anomalies to help illustrate the significant differences between the 1997/98 El Niño and the 1998/99/00/01 La Niña.

The videos also help illustrate why the effects of ENSO cannot be removed from the global surface temperature record by simply subtracting scaled and lagged NINO3.4 SST anomalies (or another ENSO index) from global temperature anomalies. There are significant residuals that contribute to global temperature anomaly trends, and these residuals are not accounted for with the simple methods used in climate studies such as Thompson et al (2009). Link (with paywall) to Thompson et al (2009):

I’ve also included animations that compare global SST anomalies with the other datasets. A sample frame that compares SST and TLT anomalies is shown in Figure 4. To indicate the timing of the maps as they proceed from El Niño to La Niña, many of the animations also include time-series graphs that fill in as time progresses.
Figure 4 – Sample Frame From Animation Of Two Datasets

Please view the animations full screen and, if possible, in high definition.

Part 1

YouTube Link
Part 2

YouTube Link

The maps were created using the map-making feature of the KNMI Climate Explorer, which was also used for the data in the time-series graphs.

The primary SST and SST anomaly data used in the animations and graphs are NOAA/Reynolds Optimum Interpolation (OI.v2) SST.

For the comparison to tropical Pacific Ocean Heat Content, a longer-term SST dataset was required, and for that graph, I used Kaplan/Reynolds (OI.v2) NINO3.4 SST anomalies from the Monthly climate indices webpage of the KNMI Climate Explorer. Link to Kaplan overview:

The other datasets used in the videos are also available through the KNMI Climate Explorer and they include:
1. International Satellite Cloud Climatology Project (ISCCP) Total Cloud Amount data. Link:

2. CAMS-OPI [Climate Anomaly Monitoring System ("CAMS") and OLR Precipitation Index ("OPI")] precipitation data. Link:

3. RSS MSU Lower Troposphere Temperature (TLT) anomalies. Link:

4. CLS (AVISO) Sea Level anomalies. Link:

5. NCEP/DOE Reanalysis-2 Surface Downward Shortwave Radiation Flux (dswrfsfc) anomalies. Link:

There is also an animation of the Equatorial Subsurface Temperature Cross-sections that are available through the ECMWF website:

The Trade Wind Index (5S-5N, 135W-180) Anomaly data is available through the NOAA CPC website. Scroll down to the second grouping for the anomaly data:

The first detailed posts on the multiyear aftereffects of El Nino events are:
Can El Nino Events Explain All of the Global Warming Since 1976? – Part 1
Can El Nino Events Explain All of the Global Warming Since 1976? – Part 2
Supplement To “Can El Nino Events Explain All Of The Warming Since 1976?”
Supplement 2 To “Can El Nino Events Explain All Of The Warming Since 1976?”

The impacts of these El Nino events on the North Atlantic are discussed in:
There Are Also El Nino-Induced Step Changes In The North Atlantic
Atlantic Meridional Overturning Circulation Data

The Lower Troposphere Temperature (TLT) anomaly responses are discussed in:
RSS MSU TLT Time-Latitude Plots... Show Climate Responses That Cannot Be Easily Illustrated With Time-Series Graphs Alone
El Ninos Create Step Changes in TLT of the Northern Hemisphere Mid Latitudes

The misrepresentation of ENSO in climate studies are discussed in the following (The discussions are similar but there are differences in the presentation):
Climate Studies Misrepresent The Effects Of El Nino And La Nina Events
The Relationship Between ENSO And Global Surface Temperature Is Not Linear
Multiple Wrongs Don’t Make A Right, Especially When It Comes To Determining The Impacts Of ENSO
Regression Analyses Do Not Capture The Multiyear Aftereffects Of Significant El Nino Events.”

Posts related to the effects of ENSO on Ocean Heat Content are here:
ENSO Dominates NODC Ocean Heat Content (0-700 Meters) Data
North Atlantic Ocean Heat Content (0-700 Meters) Is Governed By Natural Variables
North Pacific Ocean Heat Content Shift In The Late 1980s

Detailed technical discussions can be found here:
More Detail On The Multiyear Aftereffects Of ENSO – Part 1 – El Nino Events Warm The Oceans
More Detail On The Multiyear Aftereffects Of ENSO - Part 2 – La Nina Events Recharge The Heat Released By El Nino Events AND...During Major Traditional ENSO Events, Warm Water Is Redistributed Via Ocean Currents.
More Detail On The Multiyear Aftereffects Of ENSO - Part 3 – East Indian & West Pacific Oceans Can Warm In Response To Both El Nino & La Nina Events


Andrew said...

If both El Nino and La Nina result in warming of the East Indian/West Pacific Ocean, how can these basins cool? There have been El Ninos and La Ninas for as long as we can determine with proxies, and if these phenomena have been elevating the surface temperatures over an over again, shouldn't that ocean basin have evaporated away by now? So something must cool them, but what is it?

Bob Tisdale said...

Andrew: You asked, "If both El Nino and La Nina result in warming of the East Indian/West Pacific Ocean, how can these basins cool?"

The East Indian And West Pacific Ocean dataset isn't an isolated, stand-alone basin. Those portions of the oceans are constantly mixing with the adjacent portions of the North and South Pacific and Indian Oceans. They also don't remain elevated after the cumulative effect of an El Nino and La Nina event; that is, they aren't rising and staying at a new level indefinitely. There is decay in the temperature, but when they are elevated, they are adding to the temperature of the adjoining parts of the ocean basins.

One thing is certain: there are ENSO residuals that are not accounted for using the methods of Thompson et al, and those residuals add to the positive trend.


thefordprefect said...

As I have been banned for refusing to apologise, child like (i didn't have to mean it - just say it), for a statement of belief I made on watts site I will post this here
A number of videos:

I made these a couple of monts ago from various sources SST/NH Ice
The blog shows them in lower definition Flash 10 format on the referenced page but also available in mpeg 4 for higher definition in the linked files.

As I wrote, the videos are quick and simple to do so if you have a link to time organised pictures I can easily create more. Let me know on the blog as I rarely come here!

Alessandro Patrignani said...

Great work !!!

I'm working too to understand the climate step after el Nino 97/98 and I found in your posts lots of good materials.

Since 1976 the AMO index was rising and the 97/98 El Nino produced a big step in the AMO index rising. So it's possible that the new THC flow had a change in Pacific too. And this can be a reason why IPWP had a climate step after el Nino 97/98.

Pinatubo in 1991 looks a good killer for the extreme events of El Nino 97/98.

Unknown said...

Very useful information! I also think you should focus on the fact that not all El Niño and La Niña events are the same. For example... what was it about the 1995/96 La Niña that recharged ocean heat content so much when it was actually a rather weak event? Why was this the case after a quick succession of El Niño or near El Niño conditions that basically lasted from summer 1991 through spring 1995? And why didn't the La Niña of 2007/08/09 recharge nearly as much heat to the ocean? Also, while it shouldn't be accepted that La Niña is the opposite of El Niño, in terms of U.S. winter weather, it more often is than isn't. El Niño tends to favor conditions that bring warmth to the northern tier, especially the upper midwest and and northwest while it brings cold weather to the southeast. Meanwhile, La Niña tends to bring cold to the Northwest and upper Midwest with warmth across the southeast. In the Northwest, La Niñas almost always bring cool conditions while El Niños bring warm conditions and the opposite occurs int he southeast. The effects aren't always as consistent in the southwest or northeast.. but this is because of other factors that work with ENSO like the AO, NAO, and Pacific North American pattern (which is incredibly important and under mentioned). I should also point out that the La Niña winters of 1998/99 and 1999/2000 were hardly typical cold events in the United States. A rare combination of a positive PNA index with La Niña kept Arctic air locked up in western Alaska and in the Bering Sea. The positive PNA with a positive AO and NAO brought a strongly zonal jet stream that brought very mild conditions to the entire lower 48 states. 2007/08 and 2008/09 behaved like most La Niña events (1973/74, 1949/50, and 1988/89 being good comparisons) with the core of cold in the upper midwest (namely Minnesota and North Dakota) and across the Pac Northwest with very mild conditions in the east. I appreciate all the research you do into ENSO.. it is probably the largest variation in climate and weather on the planet and it warrants intense scrutiny.. and I think you "get it"... you have the ability to think outside the box and learn from ENSO events more objectively without the lens of AGW on top.

Bob Tisdale said...

Bryan: Thanks for the kind words and suggested additions. There were many other topics I wanted to include in the video, but there's just so much time available. YouTube has a 10-minute cap on videos. The other factor: only one person out of three or four goes on to watch the second part of a two part video; at least, that's my experience. (That's why I tried to include things in the second one, like the comparison animations, that would make people interested in the second.)


magellan said...

HadCRUT land and SST data are not available on their website. Could there be a surprise waiting for us from Met O as IIRC there was talk of them taking over the temperature reporting.

It seems I read some at Met O have bought into Hansen's Arctic phantom temperature data. It is strange though, wasn't it Hansen who claimed he could measure "global" temperatures using only a handful of thermometers because anomalies only matter?


Bob Tisdale said...

d: Try this for HADCRUT3:
And this for HADSST2:
And this for CRUTEM3:

The first column of data in the above webpages should be the monthly anomaly.

Bob Tisdale said...

erl: Sorry. I intended to delete an advertisement that was posted after yours but somehow your comment wound up being deleted also.

But I belive I recall one of the parts of your comment. The problem with indices is that people like to use them for regression analyses, and the point I've been trying to make is that ENSO indices such as the SOI or NINO3.4 SST anomalies miss the multiyear aftereffects of some, but not all, ENSO events.

Bill Illis said...

Hi Bob, I think this is a really, really good piece here.

I guess I would be one of those using the indices in a simple regression. I note there is certainly some after-affects like in the mid-1940s warming and then the step change that occured after the 1997-98 El Nino. There is certainly something there.

I guess I'm just looking for simple mathematical calculations that are not as prone to data selection or data plugging that climate science seems to rely on so much.

The reconstructions I use don't include the volcanoes for example because their impact is so variable and doesn't make sense compared to short-wave radiation reflected - there should be much more temperature reduction compared to the forcing reduction. To include volcanoes, one has to actually just plug guess-estimates that change from volcano to volcano so I don't use them at all.

Just using a simple non-multi-year Nino 3.4 model works good enough in my opinion. I'd like to see an analysis of the after-affects that could be used reliably for all the events and I'm sure the reconstructions would be improved which is the ultimate objective.

Andrew said...

Bill Illis-regarding the issue of volcanic forcing, you say:

"their impact is so variable and doesn't make sense compared to short-wave radiation reflected - there should be much more temperature reduction compared to the forcing reduction."

Two points: First, the forcing associated with pre-Pinatubo volcanoes, is very uncertain, so it is not surprising that the fit to Pinatubo wouldn't work for other volcanoes, at least not as well. This explains the "variable" effects. The reason the temperature reduction is small compared to the forcing, is because the response is not realized to equilibrium. The forcing is abrupt and shortlived, meaning only a very small part of the cooling actually occurs. Indeed, the delay in response is a larger effect on the volcanic dips than the climate sensitivity is, since very sensitive models and moderately sensitive models all tend to predict about the same initial temperature decrease. The only difference connected with the sensitivity is generally the speed of the recovery. For example, from Lindzen and Giannitsis:


The exact results differ with different choices for certain parameters, but notice that for a climate sensitivity of .72 degrees Celsius for doubling CO2, the maximum cooling differs from a sensitivity 4.8 degrees C for doubling CO2, by less than .1 C. This is why the response doesn't "make sense" to you: it isn't like a linear regression, it's a damped response.

John said...

Hi Bob -

Off topic, and I know you are not a strong ice-follower, but do you think the low artic ice levels are being impacted by the poleward Nino heat transfer?

It seems that the Oiv2 artic sea surface temps are not high, so I'm curious why the relatively rapid melt is occuring.


Bob Tisdale said...

John: The decrease in Arctic sea ice is impacted by many things annually, including sea level pressure, wind direction, changes in Arctic ocean currents, etc., in addition to Arctic temperatures.


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