Tag Archives: El Nino

So, are we going to have an El Nino, or what?

Officially, 2014 closed without an official El Nino. Probably. If you went back in a time machine to the spring, and told El Nino watchers that, they would be a little surprised, but they would also say something like, “Yeah, well, you know, we keep saying this is hard to predict.”

Despite the fact that for the most part there was not an official El Nino declared, a subset of El Nino conditions have been around, off and on, for many months. To officially declare an El Nino, a number of things have to add up, and while some of those things developed, the standard was not met. A few weeks ago, the Japan Meteorological Agency did retroactively say that there had been an El Nino, but others are not really going along with that. Some agencies are saying something similar but with less certainty.

Over the last few days, a number of new statements about El Nino have come out, and it looks like we are not too likely to see a large El Nino in 2015, but maybe a weak one. Or maybe none. (But some who watch this phenomenon have quietly suggested there could be a strong one.) Here are some of those statements.

Let’s start with the Australian Bureau of Meteorology ENSO Wrap-Up:

Tropical Pacific Ocean moves from El Niño to neutral
Issued on 20 January 2015
Since late 2014, most ENSO indicators have eased back from borderline El Niño levels. As the natural seasonal cycle of ENSO is now entering the decay phase, and models indicate a low chance of an immediate return to El Niño levels, neutral conditions are considered the most likely scenario through into autumn.

Central tropical Pacific Ocean surface temperatures have fallen by around half a degree from their peak of 1.1 °C above average in late November. Likewise, the Southern Oscillation Index has weakened to values more consistent with neutral conditions, while recent cloud patterns show little El Niño signature. As all models surveyed by the Bureau favour a continuation of these neutral conditions in the coming months, the immediate threat of El Niño onset appears passed for the 2014–15 cycle. Hence the ENSO Tracker has been reset to NEUTRAL. The Tracker will remain at NEUTRAL unless observations and model outlooks indicate a heightened risk of either La Niña or El Niño developing later this year.

From NOAA’s climate prediction center, from a statement issued on January 8th, 2015:

Although the surface and sub-surface temperature anomalies were consistent with El Niño, the overall atmospheric circulation continued to show only limited coupling with the anomalously warm water. The equatorial low-level winds were largely near average during the month, while upper-level easterly anomalies continued in the central and eastern tropical Pacific. The Southern Oscillation Index (SOI) remained slightly negative, but the Equatorial SOI remained near zero. Also, rainfall remained below-average near the Date Line and was above-average over Indonesia (Fig. 5). Overall, the combined atmospheric and oceanic state remains ENSO-neutral.

Similar to last month, most models predict the SST anomalies to remain at weak El Niño levels (3-month values of the Niño-3.4 index between 0.5oC and 0.9oC) during December-February 2014-15, and lasting into the Northern Hemisphere spring 2015 (Fig. 6). If El Niño were to emerge, the forecaster consensus favors a weak event that ends in early Northern Hemisphere spring. In summary, there is an approximately 50-60% chance of El Niño conditions during the next two months, with ENSO-neutral favored thereafter (click CPC/IRI consensus forecast for the chance of each outcome).

And now a shout out from NOAA, January 15th:

CURRENT ATMOSPHERIC AND OCEANIC CONDITIONS CONTINUE TO SHOW MIXED SIGNALS
REGARDING THE ENSO STATE. SEA-SURFACE TEMPERATURES (SSTS) REMAINED NEAR TO
ABOVE AVERAGE FOR MOST OF THE EQUATORIAL PACIFIC, BUT THROUGH EARLY JANUARY,
THE ATMOSPHERIC RESPONSE IS NOT ROBUST. TAKEN AS A WHOLE, THE ENSO SYSTEM
REMAINS IN AN ENSO NEUTRAL STATE, WITH SOME ASPECTS OF A WARM EVENT. THE
CHANCES OF EL NINO DEVELOPING DURING THE NEXT 2 MONTHS ARE 50-60 PERCENT, WITH
A RETURN TO ENSO NEUTRAL CONDITIONS FAVORED THEREAFTER.

(I thought they were going to stop using all caps.)

From the International Research Institute for Climate and Society, Columbia University, IRI ENSO forecast:

During December 2014 through early January 2015 the SST exceeded thresholds for weak Niño conditions, although the anomaly level has weakened recently. Meanwhile, only some of the atmospheric variables indicate an El Niño pattern. Most of the ENSO prediction models indicate weak El Niño conditions during the January-March season in progress, continuing through most or all of northern spring 2015.

And now a few pullouts from the January 19th ENSO: Recent Evolution, Current Status and Predictions report from NOAA, a PDF file chock full of graphics and stuff put out every month.

This table (of ONI Index values) puts the current year in context of previous El Nino (red) and La Nina (blue) seasons. It is interesting to look at how long it has been since the last strong El Nino event. Most of 2012, and all of 2013 and 2014, qualify as being enough of anything by this measure to call it anything other than Neutral.

Screen Shot 2015-01-20 at 10.07.36 AM

This graphic summarizes the chance of El Nino over coming months.

Screen Shot 2015-01-20 at 10.08.03 AM

ENSO Alert System Status: El Niño Watch
ENSO-neutral conditions continue.
Positive equatorial sea surface temperature (SST) anomalies continue across
most of the Pacific Ocean.
There is an approximately 50-60% chance of El Niño conditions during the
next two months, with ENSO-neutral favored thereafter.

So, did we have an El Nino? Not officially, though some features that make up this phenomenon were present, off and on, over the last several months. Will we have an El Nino? Well, the indications we are having now are not too different than what we have been having, so who knows? My personal opinion is that the last year and the coming months together are going to have to be looked at carefully to determine if the way in which El Nino is measured need to be tweaked. But, that is nothing new, there is an ongoing conversation among climatologists about this.

The graphic at the head of the post is from “Fishing in pink waters: How scientists unraveled the El Niño mystery.”

How scientists unraveled the El Niño mystery

The Road to Paris is a web site created by the ICSU, “…a non-governmental organization representing a global membership that includes both national scientific bodies (121 National Members representing 141 countries) and International Scientific Unions (30 Members),” founded in 1931. If the ICSU had not existed when the UN was formed, the UN would have formed it. Think of the ICSU as the UN of Science. More or less.

(Follow Road to Paris on Twitter.)

Anyway, Road to Paris refers to the 2015 international meetings on climate change, and the purpose of the web site is to provide excellent information about climate change, up to date, so those engaged in that process, either as direct participants or as onlookers, will be well informed.

Fishing in pink waters: How scientists unraveled the El Niño mystery” is an amazing piece of work written by Daniel Gross (I made minuscule contributions), looking at the history of the science of the El Nino Southern Oscillation, which is one of the most important climate or weather related things on this planet. This is timely, because we are expecting an El Niño to form over the winter. Maybe. Well, eventually we will have an El Niño. (It has been an unusually long time since the last strong one.)

Please visit this web page, read it, enjoy it (it is highly interactive), and spread it around.

The Amazing, Impressive, Powerful Amanda

Usually when I make a sentence like that it is about my wife, Amanda. But this time we’re talking about Hurricane Amanda, the first hurricane of the Eastern Pacific hurricane season.

Amanda reached maximum winds of 155 mph on or about 8:00 AM Pacific Daylight Time on Sunday morning. That make Amanda the strongest Eastern Pacific May Hurricane on record. There are usually very few hurricanes in the Eastern Pacific in May, and the few that occur happen late in the months. Here’s the historical distribution of Eastern Pacific hurricanes, form 1966-1996:

East_pacific_tc_climatology

Amanda is the earliest on record Eastern Pacific Category 4 hurricane.

The hurricane date for the Eastern Pacific is not well organized and accessible (without working hard) as far as I can tell. Wikipedia is shamefully badly organized and out of date, and the NWS focuses much more on Atlantic hurricanes because they are far more likely to menace the US (though Eastern Pacific storms of course can end up in Hawaii, and occasionally hit the US West Coast … and one actually slammed into Texas!).

So I can’t say much more about Amanda. The extra intensity and early date is certainly related to enhanced sea surface temperatures in the region, but the relationship between that and the possible coming El Niño can not be established at this time. Putting this another way, we can ask the question, is the Eastern Pacific Hurricane Season going to be affected by El Niño, the answer is clearly: We’ll see.

Amanda has weakened since, and is expected to continue to weaken as she moves north and turns into a tropical storm.

El Nino 2014: Historic?

The weatherologists have more or less stopped saying there might be an El Niño this year. Now they are saying there will be an El Niño, and they are starting to consider how strong it will be. Well, actually, they’ve stopped doing that too and are now talking about whether it will be a mondo-El Niño or a mondo-mondo-El Niño.

Here is a newly released video by Peter Sinclair and the Yale Climate Forum about the coming El Niño:

I have a prediction to make. First a bit of background.

You know about the so-called “hiatus” in global warming, because every Tea Partier with a mouth is yammering about it. (See this for a nice response to Sean Hannity’s most recent yammering.) There is a slowing down of the increase of what we call “surface temperatures” over the last several years. However, there are at least two major categories of cause to consider when thinking about this slowdown. First, “surface temperatures” do not reflect the totality of global warming. Surface temperature is a summary of several important parts of the planet, mainly the lower part of the atmosphere and the very top layer of the ocean. The vast majority of the heat added to the system by increasing CO2 in the atmosphere actually goes somewhere else; it goes into the oceans. I’ve talked about this problem of measurement here and here. So, we expect that actual “global warming” (the total warming of the Earth because of added CO2) to be one thing, and “surface temperatures” to reflect but not perfectly track that. (Having said that the term “Global Warming” usually refers just to surface temperatures, a terminological glitch, in my opinion, that arises from the historic uses of the terms among scientists.)

The second feature of the so called hiatus, aka #FauxPause, is that even within that part of the planetary system that is measured and summarized as “surface temperature” there are biases. Much of interior Africa and huge regions of the poles are not as accurately measured, or are simply not included in the squiggle that we use to represent global warming. Recent analysis, however, has estimated the degree and direction of that bias, and it turns out that the bias is towards the negative — we have been missing heat. When you put that heat back into the squiggle, the so-called hiatus gets less hiatusy.

What does all this have to do with El Niño? And my prediction? Here’s the thing. El Niño is part of a larger ongoing continuous climatological phenomenon referred to as ENSO. This is a cyclic (but not periodic) phenomenon having to do with surface heat being plowed into the deeper ocean for a period of time then coming out later. When the heat comes out, the “surface temperatures” go up. If we have the mondo-, or especially the mondo-mondo- El Niño people are expecting, a whopping pile of heat that has been hiding in the Pacific Ocean is going to spring from the sea and heat up the air. Expect heat.

In Anthropology we have a concept called the “Nature-Nurture Dichotomy.” You know what this is because you have made references to it frequently in day to day life. Nature is learned, enculturated, received behavior or personality or whatever. If you water your plants more or less they grow more or less. If we raise our children to be more or less violent, we may get a society that is more or less violent. That sort of thing. Nature is the built in part. A gene causes men to be more violent than women, or women to be more nurturing than men. The “men are from Mars” and “women are from Venus” thing is a statement — unsupported by science and way oversimplified to the extent of being stupid and useless, I quickly add — about nature. According to the Nature-Nurture dichotomy model, we, our plants, other living things, can be described as the outcome of innate (genetic) causes and external, learned or environmental causes. Indeed, according to this framework, we can characterize a feature of a person or a plant or whatever as X percent nature and Y percent nurture, adding up to 100%.

The nature-nurture dichotomy is a falsehood. It is wrong. It is incorrect. It is not supported by the data. This is not to say that there are not “built in” features of living systems and “environmental” features of living systems. But, the stark distinction between the two, the lack of consideration of interaction between the two, and the simplified partitioning of causality to add up to 100% between the two are all demonstrably wrong. Not only are those things wrong, but Nature-Nurture dichotomy thinking is misleading.

What does this have to do with El Niño and global warming and stuff?

If global warming was not happening, the surface temperature measurements would look like a flat squiggle over time, going up and down but averaging out over just a few years or a decade or two. There are many “natural” features of the climate system that act like this, such as the strength of the sun or the effects on surface temperatures of aerosols (i.e. volcanic dust). ENSO is such a thing, a natural squiggling of effects on surface temperatures.

Human release of Carbon Dioxide into the atmosphere is also a squiggle, potentially varying from year to year, but the effects of CO2 release have been to increase the baseline temperature over time.

The following graph is a made up version of this. The squiggles in the lower part of the graph represent a set of natural factors that influence the final outcome; they vary with their own up and down pattern. Just above that is a single upward tending variable. The line in the topmost part of the graph is the sum of all of these.

The_Nature_Of_Climate_Squiggles

When temperatures started to flatten out over the last few years (they did not decrease, and they kept rising, but at a slower rate) climate change denialists made the claim that this was because anthropogenic global warming (represented by that middle, upward trending line in the made up graph) wasn’t real. Climate scientists argued that there were two or three reasons the graph flattened out a bit. One of those reasons is the simple, overarching claim that natural variation (like ENSO) makes the graph squiggle up and down independently of anthropogenic global warming. The climate scientists were correct, the science denialists were wrong, of course.

Now, with ENSO about to produce an El Niño, we are probably going to see the squiggle that is the sum of all squiggles squiggle upward, perhaps rather dramatically. The heat that has been hiding in the ocean will return to the “surface” (lower atmosphere and top layer of the oceans).

I predict that denialists will claim that this is not global warming, but rather, natural variation, so therefore global warming is not real.

The first part of that is sort of true, but if so, it was ALSO TRUE that the flattening out of the overall surface temperature curve, and much or all of the squiggle in that line over many decades, is explained by natural variation.

In other words, denialists will have ended up saying: “The pause is true because AGW is not true. The upward swing in 2014/5 is not real because is is natural.”

Climate scientists will say “The pause was an artifact of the natural process of heat plowing into the ocean and the resurgence of surface temperatures in 2014/5 is due to the natural process of that heat coming back to the surface, all of this playing out on a generally upward trending surface temperature graph.”

See the difference?

I’d like to add, taking the aforementioned anthropological perspective, that the nature-nurture (natural/anthropogenic) dichotomy is actually present in this argument and mucking it up a bit. The resurgence in temperature increase we are likely to see over the next year or so is not a “natural” occurrence in that the actual heat is “natural.” Some of that heat, we humans made. So you can’t really call it natural variation. This is more of a linguistic point than anything else, because the natural variations of which we speak are “variations” more than they are “natural” or “not natural.” And the science of climate is, like science in general, all about variation. In the end, the trend of temperature change over the last half of the 20th century up to the present and for decades to come is an increase (a kind of variation) pretty much all caused by human release of CO2 and related effects. In the end, the squiggly nature of the line that represents that trend will end up being a combination of natural features and changes in the human effect. This has been true for decades, it is true right now, and it will continue to be true for a long time.

Atlantic Hurricanes and El Niño

I have a little “science by spreadsheet” project for you, concerning the relationship between El Niño and Atlantic hurricanes.

The chance of an El Niño event happening this year seems to go up every few days, with most, perhaps all, climate models suggesting that El Niño will form this Summer or Fall. Climate experts tell us that there are typically fewer hurricanes in the Atlantic during El Niño years. So, I was interested to see how many fewer. Also, there appears to be a different kind of El Niño that happens sometimes, perhaps more often these days as an effect of global warming, which is variously referred to as Modoki or Central Pacific El Niño. The definition of this type of event, and even whether or not it is real, is not well established, but it has been said that the effect of this version of El Niño on Atlantic hurricanes is different.

The data used for this analysis covers the period from 1950 to 2012, simply because that is the range of years for which El Niño and hurricane data are readily available for copy/paste into the spreadsheet. Aside from numbers of hurricanes, we’ll look at the Accumulated Cyclone Energy index (ACE). This is a value calculated from the storms that occur, using measures of wind speed over the life of the storm. Since tropical storms and hurricanes vary in ways not captured by simply counting them, or even by counting them by standard categories (one through five), this measure is a better reflection of overall major storminess in the region. The following figure shows the relationship between ACE and frequency of hurricanes in the Atlantic Basin. Please keep in mind that the clear relationship between these numbers is a given: ACE is calculated, essentially, from Number of Hurricanes together with a measure of hurricane strength, so the same variable (number of hurricanes) is on both axes of the graph. The purpose of this graph is to give an idea of the variation of hurricane frequency around the measurement of overall energy in the system, so this really mainly shows how complex the manifestation of hurricanes in a given season is.

Screen Shot 2014-04-23 at 8.40.47 AM

Now let’s look at the relationship between the number of named Atlantic tropical storms, hurricanes, and major hurricanes, in El Niño, no-El Niño, and CP El Niño years, as well as the ACE.

Screen Shot 2014-04-23 at 8.25.41 AM

Without bothering with any statistical tests or other mumbo-jumbo (this is Science by Spreadsheet, after all) we can see that the number of named storms, hurricanes, and major hurricanes, as well as the ACE index, are all higher in years that do not have an El Niño. But, it is also apparent (again, no statistical tests) that the difference is not huge. In other words, if you live in a hurricane susceptible area, and you are thinking that you’re not going to have a problem with hurricanes this year because there will probably be an El Niño, think again. There are still going to be hurricanes. Also of interest is that CP El Niño years, of which there are only a few, are like regular El Niño years though maybe the reduced number of major hurricanes is a real phenomenon. (Also note, in these data most of the “CP El Niño” years are also El Niño years, but not all, in case you were trying to add up the values of N.)

Another way of looking at the same data is to ask what percentage of named storms develop into hurricanes, or major hurricanes, under these different ENSO conditions. Here are the percentages:

Screen Shot 2014-04-23 at 8.35.27 AM

So, just over half of the named storms develop into hurricanes in an average year, regardless of El Niño, and about a quarter into major hurricanes. CP El Ninño years seem to show, as we saw above, less development of major hurricanes. But, the total number of these years is small, so this may mean nothing.

Remember last year’s Atlantic hurricanes? No, nobody else does either. It was an anemic year for Atlantic hurricanes. This is attributed to the giant plume of Saharan dust that attenuated tropical storm development in the basin that year. It might be reasonable to say that the number and intensity of hurricanes per year is highly variable for a lot of reasons, and factors such as Saharan dust may have very large impacts on hurricane formation. In other words, the variation introduced into the system by El Niño may be important but not overwhelming.

In order to look at the overlap between El Niño and non El Niño years, I made this frequency histogram:

Screen Shot 2014-04-23 at 9.34.30 AM

(Note that this frequency histogram uses intervals of 3 years; the one year on “30” is a year with 28 storms, falling into the interval 27.1 to 20. Science by spreadsheet has its limitations.)

There is a certain amount of overlap. Extremely active Atlantic hurricane seasons seem to only occur in non-El Niño years, over on the right side of the graph, but the distributions of named storm frequency is not separate and distinct. Another way of looking at this is to note that the range of number of named storms per year for non El Niño years is 4-20, while the range of number of named storms for El Niño years is 6-18.

Sea surface temperatures influence Atlantic hurricane formation. Here’s a graph from someone else’s spreadsheet showing this relationship:

"A graph showing the correlation between the and the number of major hurricanes which form in the Atlantic basin. Moving averages for AMO are by the years' average indexes, 5 years before and 5 years after, not the provided 121-month smoothing."
“A graph showing the correlation between the and the number of major hurricanes which form in the Atlantic basin. Moving averages for AMO are by the years’ average indexes, 5 years before and 5 years after, not the provided 121-month smoothing.”
:

Clearly, a large proportion of hurricane frequency is explained by variations in sea surface temperature. Clearly, Saharan dust explains some of the variation. El Niño also explains some of the variation, but it is only part of the story.


AMO-Hurricane graph
El Ninño year data
Tropical storm data
CP El Ninño data

The Christ Child Cometh.

… and by that I mean the El Niño phase of the El Niño Souther Oscillation climate pattern.

We have been in an ENSO neutral phase for a while. Climate scientists have a hard time predicting El Niño, which arrives in Summer, Fall, or Winter, this early in the year, but nonetheless most prediction sources, and most models, now tell us that we are likely to have one staring, really, any time, but most likely Summer or Fall. Here’s a graph of several models. The bottom colored area is Le Niña, who we assume was Jesus Christ’s sister, and the top colored area is El Ninño, with the middle part being neutral. What is being measured here is sea surface temperature anomaly in certain areas of the Pacific Ocean.

pauldouglas_1397607481_ElNinoAus

The ENSO is complex and I won’t try to explain it all here, but the bottom line is this: During some periods heat accumulated on the surface of the Pacific is moved by currents (driven by winds) deeper into the ocean. During other periods, El Niño, the heat moves back to the surface again.

It is interesting to note that there are probably two kinds of El Niño: Regular and “Modoki”. Modoki is Japanese for “Similar but different.” So perhaps we can think of Modoki El Niño as Brian. Anyway, the Modoki El Niño is different in a few ways, one of those being that while regular El Niño tends to attenuate Atlantic hurricane activity by causing more tropical storm-killing vertical wind shear, the Modoki variety may enhance the likelihood of landfalling hurricanes in the US. I’ve not seen any predictions that we are more likely to have Modoki El Niño this year, but a paper just coming out on a related topic, that I’m busy writing up suggests that it may be the case.

For more information on this year’s predictions, see these sources:

EL NIÑO/SOUTHERN OSCILLATION (ENSO) DIAGNOSTIC DISCUSSION (NOAA)

El Niño likely to develop in winter (Australian Bureau of Meteorology)

Comment on El Nino Post on 538

The 538 comment system appears to not be working, probably because of my current highly suspicious location, so I figured I’d put my comment here (since I spent a whole minute writing it):

“Long-range forecast models have come to a consensus recently that a minor to moderate El Niño pattern may develop six to nine months from now.

That just isn’t true. Forecasts suggest a 50-50 chance of El Nino, but this is hard to predict. There is no consensus that an El Nino will develop among forecasters who are always super cautious about this prediction and there is only a 50-50 chance.

Also, I see no one saying it would be a moderate El Nino. Do yo have a reference for that? Some, in private, are putting their money on a strong El Nino if one happens, but not saying so publicly because the uncertainty is so high it would be irresponsible (or embarrassing if wrong!)

Regarding California’s lack of water, this may be harder to predict. An El Nino may or may not bring “drenching rains” but it is snow pack that probably matters more, and a single year of El Nino heavy rains may do nothing, so you may have that right. Overall, I agree that the earlier statements about ho El Nino will fix everything were somewhat bogus because, in part, they were being made when ENSO forecasts woul dhave been very tricky and they aren’t much better now.

Finally what is the behavior of a longish term oscillation like ENSO under dramatically changing climate, an the effects of that pattern on other patterns? ENSO affects climate by altering things like jet stream behavior and trade winds. But the Arctic is kicking butt in that area these days. Will we be seeing a major face-off between ENSO oscillation and Arctic Amplification???

Here’s the post that comment goes with.

I haven’t said much a out 538 and recent forays into climate and weather, but at the moment I’d classify 538 as a Junk Science site, which is highly disappointing. Let’s hope Nate Silver decides to fix that. Taking on an area of science and totally woo-ing out is reputation destroying stuff. It’s not like there isn’t a plethora of talent out there he could tap into.