Archives par mot-clé : El Nino

climate-debate

The 2023 global warming spike was driven by the El Niño–Southern Oscillation

by S.P. Raghuraman et al., Oct 2024 in EGU-APCPapers

Abstract

Global-mean surface temperature rapidly increased 0.29 ± 0.04 K from 2022 to 2023. Such a large interannual global warming spike is not unprecedented in the observational record, with a previous instance occurring in 1976–1977. However, why such large global warming spikes occur is unknown, and the rapid global warming of 2023 has led to concerns that it could have been externally driven. Here we show that climate models that are subject only to internal variability can generate such spikes, but they are an uncommon occurrence (p = 1.6 % ± 0.1 %). However, when a prolonged La Niña immediately precedes an El Niño in the simulations, as occurred in nature in 1976–1977 and 2022–2023, such spikes become much more common (p = 10.3 % ± 0.4 %). Furthermore, we find that nearly all simulated spikes (p = 88.5 % ± 0.3 %) are associated with El Niño occurring that year. Thus, our results underscore the importance of the El Niño–Southern Oscillation in driving the occurrence of global warming spikes such as the one in 2023, without needing to invoke anthropogenic forcing, such as changes in atmospheric concentrations of greenhouse gases or aerosols, as an explanation.

Received: 24 Jun 2024 – Discussion started: 08 Jul 2024 – Revised: 04 Sep 2024 – Accepted: 23 Sep 2024 – Published: 10 Oct 2024
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climate-debate

El Niño fingered as likely culprit in record 2023 temperatures

by P. Voosen, Oct 10, 2024 in Science

For the past year, alarm bells have been going off in climate science: Last year’s average global temperature was so high, shooting up nearly 0.3°C above the previous year to set a new record, that human-driven global warming and natural short-term climate swings seemingly couldn’t explain it. Some, like famed climate scientist James Hansen, suggestedEarth is entering an ominous new phase of accelerated warming, driven by a rapid decline in sunlight-dimming air pollution. Others, like Gavin Schmidt, director of NASA’s Goddard Institute for Space Studies, said the rise might represent a “knowledge gap,” some new climate feedback that might tip the planet toward a future even warmer than models predict.

Now, a new series of studies suggests most of the 2023 jump can be explained instead by a familiar climate driver: the shifting waters of the tropical Pacific Ocean. The combination of a 3-year-long La Niña, which suppressed global temperatures from 2020 to 2022, followed by a strong El Niño could account for the unexpected temperature jump, the work suggests. “Earth can do this,” says Shiv Priyam Raghuraman, a climate scientist at the University of Illinois Urbana-Champaign, who led one study.

During La Niña, strong trade winds push warm surface water west along the equator toward Indonesia and pull up a fountain of deep, cold water in the eastern Pacific that helps cool the planet. During El Niño, the winds collapse, allowing warm water to slosh east and shut off the ocean air conditioner. Continuer la lecture de El Niño fingered as likely culprit in record 2023 temperatures →

climate-debate

Cooling The Niño

by W. Eschenbach, July 14, 2024 in WUWT

This is a two-part post. The first part is to correct an oversight in my recent post entitled Rainergy.

The second part is to use that new information to analyze the effect of clouds on the El Nino region.

So, to the first part. In my post Rainergy, I noted that it takes ~ 80 watts per square meter (W/m2) over a year to evaporate a cubic meter of seawater. Thus, the evaporation that creates the ~1 meter of annual rain cools the surface by – 80 W/m2.

Then the other day I thought “Dang! I forgot virga!”

Virga is rain that falls from a cloud but evaporates completely before it hits the ground.

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climate-debate

Strong El Nino Conditions Prevails at The End of January 2024

by A. Patel, Feb 12, 2024 in WUWT

However, This El Nino Not Expected to Be as Strong As 1982-83 Or 1997-98 Or 2015-16 El Nino

Enso Status on 10th February 2024

Ashok Patel’s Analysis & Commentary :

The classification of El Niño events, including the strength labels, is somewhat subjective and can vary among meteorological and climate agencies. There isn’t a strict rule defining the specific number of consecutive Oceanic Niño Index (ONI) values that must be 2.0°C or above to categorize an El Niño event as “Super Strong.”

In general, a strong El Niño event is often characterized by ONI values reaching or exceeding +2.0°C. A Super Strong El Niño would typically involve sustained ONI value of +2.0°C or more. Hence for ease of understanding and comparing the strength of various Strong El Nino events, I propose to define an El Nino as a Super Strong event if  three consecutive ONI index is +2.0°C or more.

A brief history of the past El Nino events with the number of consecutive ONI +2.0°C or above:

In the year 1965 the highest ONI index during that El Nino were SON +2.0°C, OND +2.0°C

In the year 1972-73 the highest ONI index during that El Nino were OND +2.1°C NDJ +2.1°C DJF

In the year 1982-83 the highest ONI index during that El Nino were SON +2.0°C, OND +2.2°C NDJ +2.2°C DJF +2.2°C

In the year 1997-98 the highest ONI index during that El Nino were ASO +2.1°C SON +2.3°C, OND +2.4°C NDJ +2.4°C DJF +2.2°C

In the year 2015-16 the highest ONI index during that El Nino were ASO +2.2°C SON +2.4°C, OND +2.6°C NDJ +2.6°C DJF +2.5°C JFM +2.1°C

ONI Data has been obtained from CPC – NWS – NOAA available here

There have been three Super Strong El Nino events from 1950 onwards till date. The first such event was 1982-83 Super Strong El Nino with 4 consecutive ONI +2.0°C or above with highest ONI of +2.2°C twice. The second Super Strong El Nino event was 1997-98 with five consecutive ONI +2.0°C or above with highest ONI of +2.4°C twice. The third Super Strong El Nino event was 2015-16 with six consecutive ONI +2.0°C or above with highest ONI of +2.6°C twice. The current forecast and analysis does not support the 2023-24 El Nino to become a Super Strong El Nino.

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climate-debate

Is the Low Snowpack this Year a Sign of Global Warming?

C. Mass, Jan1, 2024 in WUWT

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El Nino

We are in a very strong El Nino and such events are highly correlated with warm winter temperatures and poor snowpack over the region.  Sea surface temperatures have been about 2C above normal over the past two months (see below).

According to NOAA/NWS, El Nino years are associated with warmer than normal October-November-Decembers (see below for a local climate division)

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climate-debate

Why A Strong El Niño In 2023 Is Unlikely

by R. Cutler, May 25, 2023 in ClimateChangeDispatch

Global warming completely stopped in 2018. Temperatures will likely remain steady until 2025 and may decline slightly by 2030.

A strong El Niño in 2023 is unlikely.

I’ll explain all of my predictions — after we hear from the experts. [emphasis, links added]

NOAA recently predicted a 55% chance of a strong El Niñoin late 2023.

The World Meteorological Organization (WMO) threw more fuel on the fire when it announced, “There is a 98% likelihood that at least one of the next five years, and the five-year period as a whole, will be the warmest on record.”

Obviously, the MSM had a field day with this. Take for example this headline from USA Today: “Scientists warn an El Niño is likely coming that could bring scorching heat to Earth.”

Rather than taking the well-worn path of pointing out flaws in the predictions of NOAA, the IPCC, or the WMO, I’ll instead show how the sun is likely responsible for almost every detail in global temperaturesover the last 125 years, and that it is also responsible for triggering strong El Niños.

Two empirical, or black-box models were created to predict global temperature. The first model uses solar magnetic field data from the Wilcox Solar Observatory (WSO).

The second model uses sunspot data from WDC-SILSO, the Royal Observatory of Belgium, Brussels. Both predictions will be compared to global temperature anomaly data from NOAA.

Solar magnetic field data collection began in 1976. The complete WSO dataset can be viewed in a single graphic, often referred to as a butterfly diagram.

It looks complicated, but it’s really not. It’s just a plot of solar magnetic field intensity over time as a function of the sun’s latitude. The two colors represent north and south polarity magnetism.

Unlike the Earth, where magnetic north has conveniently stayed in the Northern Hemisphere for the last 780,000 years, the sun’s magnetic field changes polarity every 11 years.

climate-debate

High sea surface temperature in North Atlantic

by Arctic News, Apr 22, 2023

SST World (60S-60N)

On April 20, 2023, sea surface temperatures (between 60°South and 60°North) had been at 21°C or higher for as many as 32 days. Such temperatures are unprecedented in the NOAA record that goes back to 1981.

 

On April 4, the sea surface temperature in 2023 (black line) was as much as 0.3°C higher than in 2022 (orange line) and we’re only just entering the upcoming El Niño.

 

SST North Atlantic

The situation is especially critical in the North Atlantic. Vast amounts of ocean heat in the North Atlantic are moving toward the Arctic, threatening to cause rapid melting of Arctic sea ice and thawing of permafrost. Last year, North Atlantic sea surface temperatures reached a record high of 24.9°C in early September and, as illustrated by the image below, the North Atlantic sea surface temperature on April 20 was as much as 0.5°C higher in 2023 (black) than in 2022 (orange).

As we’re moving into the upcoming El Niño, the Arctic Ocean can be expected to receive more and more heat over the next few years, i.e. more heat from direct sunlight, more heat from rivers, more heat from heatwaves and more ocean heat from the Atlantic Ocean and the Pacific Ocean.
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unclassified

Are ENSO Regime Changes Connected To Major Climate Shifts? Are We Tipping To Cooling?

by P. Gosselin, Apr 19, 2023 in NoTricksZone

We’ve had a La Niña for nearly three years. But now it has officially ended, and ENSO has moved into its neutral phase, the “La Nada”.[1] The La Niña event lasted three winters in a row, something that has only occurred twice before in modern times: 1973–1976 and 1998–2001. Both of these followed in response to a very strong El Niño.

The La Niña that has now ended, on the other hand, came after the more neutral winter of 2019/20.

Figure 1. Number of months with each ENSO phase for five-year periods from 1950 – 2023

The number of months that we have had each ENSO phase in the last 74 years is shown in Figure 1. The La Niñas are more frequent than the El Niños. Interestingly, the opposite was true during the rapid warming we had from 1975 – 1999, when El Niños were more common. But then it reverts back again around 1998/99. Is there a pattern here?

It is established in climate science that the climate underwent a profound shift in 1976/77, related to the ocean currents.[2] In IPCC AR4, they write: “The 1976–1977 climate shift in the Pacific, associated with a phase change in the PDO from negative to positive, was associated with significant changes in ENSO evolution.” The Pacific Decadal Oscillation (PDO) shifted from a ‘cold’ to a ‘warm’ phase during these two years.[3] The ENSO also became dominated by the El Niño phase, which is characterized by warmer temperatures.[4] These changes affected the global climate, and a rapid warming began.

But what happened in the years just before 2000? As seen in Figure 1, ENSO reverts to being dominated by the ‘colder’ La Niña at that time.

Figure 2. The PDO index according to NOAA/ESRL.

Interestingly, the PDO also reverts to its cold phase in 1998–1999.

Are we seeing a shift to a colder phase in the climate here?

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climate-debate

2022 updates to the temperature records

by Gavin, Jan 13, 2023 in RealClimate

Another January, another annual data point.

As in years past, the annual rollout of the GISTEMP, NOAA, HadCRUT and Berkeley Earth analyses of the surface temperature record have brought forth many stories about the long term trends and specific events of 2022 – mostly focused on the impacts of the (ongoing) La Niña event and the litany of weather extremes (UK and elsewhere having record years, intense rainfall and flooding, Hurricane Ian, etc. etc.).

But there are a few things that don’t get covered much in the mainstream stories, and so we can dig into them a bit here.

What influence does ENSO really have?

It’s well known (among readers here, I assume), that ENSO influences the interannual variability of the climate system and the annual mean temperatures. El Niño events enhance global warming (as in 1998, 2010, 2016 etc.) and La Niña events (2011, 2018, 2021, 2022 etc.) impart a slight cooling.

GISTEMP anomalies (w.r.t. late 19th C) coded for ENSO state in the early spring.

Consequently, a line drawn from an El Niño year to a subsequent La Niña year will almost always show a cooling – a fact well known to the climate disinformers (though they are not so quick to show the uncertainties in such cherry picks!). For instance, the trends from 2016 to 2022 are -0.12±0.37ºC/dec but with such large uncertainties, the calculation is meaningless. Far more predictive are the long term trends which are consistently (now) above 0.2ºC/dec (and with much smaller uncertainties ±0.02ºC/dec for the last 40 years).

It’s worth exploring quantitatively what the impact is, and this is something I’ve been looking at for a while. It’s easy enough correlate the detrended annual anomalies with the ENSO index (maximum correlation is for the early spring values), and then use that regression to estimate the specific impact for any year, and to estimate an ENSO-corrected time series.

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climate-debate

UAH – What is Foretold

by D. Archibald, Dec 22, 2022 in WUWT

We all know that Santa’s workshop is somewhere in the Arctic, producing toys for the world’s children. Also north of the Arctic Circle is Professor Humlum’s office at the Unversity of Svalbaard wherein he toils each month to update a report on climate. The first chart in that report is the UAH temperature for the lower troposphere, copied following and annotated with lines showing the evident trends:

Figure 1: UAH global temperature anomaly

In the period from 1978 to 2015, the lower bound of the record is shown by the orange line. Then there was a period of a couple of years in which the temperature anomaly was in a narrow, steep uptrend channel. The temperature anomaly broke up from that channel due to the 2016 El Nino.

Since that 2016 El Nino, two parallel upper bounding lines have formed, in downtrend. The lower green one is formed by six points. The upper red line is formed from only two points – the minimum to make a line – but is notable in that it is parallel to the green line. So climate isn’t a randowm walk. There is some physical process that limits how far temperature excursions go.

The uptrend from the beginning of the satellite record in 1978 to 2015 was 0.4°C over 36 years. That equates to 0.000926°C per month. If we take that amount from each monthly temperature anomaly, cumulatively, we produce the following graph of the detrended monthly temperature anomaly distribution from 1978 to 2015:

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climate-debate

Global temperature hiatus may not have ended after all, new study suggests

by Dr D. Whitehouse, Sep 23, 2022 in NetZeroWatch

The so-called hiatus in global annual average temperature between 2002 – 2014, once controversial to some but now well-established in the peer-reviewed literature, ended in 2014 with the start of a series of record-breaking El Nino events that spiked global temperature with a subsequent fall-back. Now a new study into the effect of man-made aerosol pollution adds to likely reasons for the end of the hiatus, and may point to lower estimates for future global warming.

An international research team writing in the journal Atmospheric Chemistry and Physics, uses satellite data to show that concentrations of aerosol particles have decreased significantly since 2000. This is good news as cleaner air benefits health, but it also reduces particles’ which have a cooling effect on the terrestrial climate.

According to the Intergovernmental Panel on Climate Change (IPCC), by 2019 the global temperature had risen by 1.1 degrees Celsius compared to pre-industrial levels due to increasing greenhouse gasses from burning fossil fuels. At the same time the combustion of fossil fuels emit aerosols which cool our climate by reflecting sunlight and increasing the reflectivity of clouds.

Professor Johannes Quaas, a meteorologist at Leipzig University, and colleagues from Europe, China, and the US have published robust observational evidence of significant reduction of aerosol pollution and improved global air quality.

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When taken together with a couple of super-strong El Nino events which temporarily drove up global temperature (see graph below), the new findings suggest that the global warming hiatus — clearly evident prior to 2014 — may not have ended yet. If NASA’s satellite data are confirmed, it would suggest that much of the very moderate changes in global temperature this century may have been driven primarily by cleaner air and naturally-occurring El Ninos.

Global temperature changes 2000-2022. Source: Met Office/HadCRUT5
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better to know...?, climate-debate

Ancient El Niños reveal limits to future climate projections

by University of Texas at Austin, Mar 15, 2022 in ScienceDaily

The climate pattern El Niño varies over time to such a degree that scientists will have difficulty detecting signs that it is getting stronger with global warming.

That’s the conclusion of a study led by scientists at The University of Texas at Austin that analyzed 9,000 years of Earth’s history. The scientists drew on climate data contained within ancient corals and used one of the world’s most powerful supercomputers to conduct their research.

The study of the past, which was recently published in Science Advances, was motivated by the need to get a clearer picture of how climate change may affect El Niño in the future.

El Niño is the warm phase of the El Niño Southern Oscillation, a climate phenomenon that sets the stage every few years for weather patterns worldwide. Strong El Niño events, such as the ones in 1997 and 2015 that brought wildfires to the rainforests of Borneo in Asia and caused widespread bleaching to the world’s coral reefs, happened about once a decade.

Computer models, however, are unclear about whether El Niño events will become weaker or stronger as the world warms due to climate change.

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climate-debate

Ancient El Niños reveal limits to future climate projections

by University of Texas at Austin, Mar 15, 2022 in ScienceDaily

The climate pattern El Niño varies over time to such a degree that scientists will have difficulty detecting signs that it is getting stronger with global warming.

That’s the conclusion of a study led by scientists at The University of Texas at Austin that analyzed 9,000 years of Earth’s history. The scientists drew on climate data contained within ancient corals and used one of the world’s most powerful supercomputers to conduct their research.

The study of the past, which was recently published in Science Advances, was motivated by the need to get a clearer picture of how climate change may affect El Niño in the future.

El Niño is the warm phase of the El Niño Southern Oscillation, a climate phenomenon that sets the stage every few years for weather patterns worldwide. Strong El Niño events, such as the ones in 1997 and 2015 that brought wildfires to the rainforests of Borneo in Asia and caused widespread bleaching to the world’s coral reefs, happened about once a decade.

Computer models, however, are unclear about whether El Niño events will become weaker or stronger as the world warms due to climate change.

“Much of the world’s temperature and rainfall are influenced by what happens in the tropical Pacific Ocean where El Niño starts,” said the study’s lead author, Allison Lawman, who began the research as a Ph.D. project at the UT Jackson School of Geosciences and is now a postdoctoral researcher at the University of Colorado Boulder. “The difference in rainfall between greater or fewer strong El Niño events is going to be a critical question for infrastructure and resource planners.”

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climate-debate

The Sun’s climate role confirmed

by D. Whitehouse, April 6, 2021 in GWPF

“The scientific community has been unclear on the role that solar variability plays in influencing weather and climate events here on Earth. This study shows there’s reason to believe it absolutely does and why the connection may have been missed in the past.”

Top: Six-month smoothed monthly sunspot number from SILSO.  Bottom: Oceanic El Niño Index from NOAA. Red and blue boxes mark the El Niño and La Niña periods in the repeating pattern. Source: Climate Etc, September 2019

If you ask most climate scientists, they will tell you that the Sun’s small variability is unimportant when it comes to influencing climate. They may have to change their minds if a new line of research holds up. It seems that solar variability can drive climate variability on Earth on decadal timescales (the decadal climatic variability that Michael Mann recently ‘proved’ doesn’t exist). That’s the conclusion of a new study showing a correlation between the end of solar cycles and a switch from El Nino to La Nina conditions in the Pacific Ocean. It’s a result that could significantly improve the predictability of the largest El Nino and La Nina events, which have several global climate effects.

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unclassified

The Natural Warming Of The Global Oceans-Bob Tisdale

by P. Homewood, Jan 18, 3021 in NotaLotofPeopleknowThat

https://youtu.be/lmjaNO5DD_Q

Many of you will be familiar with the work of Bob Tisdale over the years, concerning the mechanism of ENSO (ie El Ninos and La Ninas) and its effects on climate.

His seminal series of videos, recorded in 2012 is still on YouTube, and is still highly relevant.

Above is Part 1, which is worth sticking with all the way through, but otherwise the first 8 minutes is definitely worth a watch. Nothing has effectively changed since 2012, and Bob’s conclusions are still relevant and valid.

As well as explaining what exactly drives El Ninos and La Ninas, he makes some significant points:

  1. Worldwide sea surface temperature trends since 1980 show no correlation with GHGs (see chart below)

  2. Instead they exhibit a series of step changes up, which follow the major El Nino events of 1982/83, 1987/88 and 1997/98

  3. Contrary to popular belief, global SSTs do not drop during La Nina episodes. This is because El Ninos transfer a vast amount of warm, subsurface water to the surface, where it remains during La Nina.

  4. Some of this warm water in the East Pacific finds its way into the West Pacific and Indian Oceans. But through a process called teleconnection, SSTs is the Atlantic, where there is no direct connection, also rise and exhibit the same step changes.

  5. Between major El Nino events, SSTs outside the East Pacific do not rise.

  6. In the East Pacific, there has been no trend increase in SST at all since 1980.

     

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climate-debate

Another warm El Nino year

by GWPF, Dec 3, 2020

2020 is gearing up to be another warm year, strongly affected by natural and regional weather events

It’s that time of the year again when some meteorological organisations predict what the average global temperature might be for the full, current year. Not that we have all the data for 2020, obviously, for most global temperature datasets haven’t even processed November’s data yet. Making a prediction with only just over 80% of the data available is a risky procedure and most sensible scientists would be very circumspect about doing so. But these premature annual announcements are done for political purposes and, in a typical year, always as a precursor to a UN climate conference.

2020 has been a warm year, one of the warmest – and warm years make many people throw caution to the wind, making claims based on select facts they like, ignoring the ones they don’t like.

Let’s go back a few years to the early part of this decade when global temperature had been stagnating for more than ten years and not increasing significantly, as many had predicted. But then came 2014-15 when they started rising again, peaking in 2016. Many voices proclaimed that this was evidence that global temperatures were now accelerating ‘out of control’, something their models had been predicting all along. The climate was making up for all the unchanging years of the so-called global warming hiatus, it was claimed.

Never mind that the sudden rise between 2015 and 2016 was occurring much faster than could be due to greenhouse forcing alone.

2010 – 2020: HadCrut4 global surface temperature change (green); Oceanic Niño Index (ONI) (red/blues)

However, it was not a coincidence that 2016 experienced a record El Nino. For some commentators, however, an El Nino is a finite event. According to its definition – a specific temperature increase in a certain region of the Pacific – an El Nino is either on or off. Hence, they said that subsequent warm years after 2016 were warm due to greenhouse forcing, not El Nino. They argued that average global temperature since then was not influenced by any El Nino warming.

But that’s clearly not the case. The build-up in temperatures before recent El Ninos is obviously not independent of its peak and neither is the decline afterwards, else why did that increase not continue after the El Nino’s ‘interruption.’ So, a year can still be showing the warming influence of previous El Nino conditions whilst not having an El Nino event, something many journalists and even the General Secretary of the World Meteorological Organisation (WMO), Prof Taalas, prefer to ignore.

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better to know...?, climate-debate

Uncertain Certainty: Germany’s Potsdam Climate Institute Humiliated After One-Year El Nino Forecast Model Flops

by P. Gosselin, Nov 15, 2020 in WUWT

Last year Germany’s Potsdam Institute (PIK) boasted that it had a superior El Niño one-year forecasting model, claiming 80% certainty. Today, a year later, its forecast emerges totally wrong and the prestigious institute is left humiliated. 

Hat-tip: Snowfan

In 2019, Germany’s Potsdam Climate Institute (PIK) boasted that it had a superior El Niño forecasting model, claiming one year in advance and with 80% certainty, there would be an El Niño event late in 2020 (upper curve is just an El Niño illustration). But the PIK model forecast flopped totally. The opposite has in fact emerged. Chart source: BOM (with additions).

One year ago, together with researchers of the Justus Liebig University Giessen (JLU), and Bar-Ilan University in Ramat Gan in Israel, Germany’s alarmist yet highly regarded Potsdam Institute for Climate Research (PIK) boldly declared in a press release there would “probably be another ‘El Niño’ by the end of 2020.”

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unclassified

El Nino & Arctic Warming In the 1930s

by P. Homewood, April 5, 2020 in NotaLotofPeopleKnowThat

Just following up on Joe Bastardi’s article yesterday about El Ninos and Arctic warming, it is worth looking at longer term trends.

Below is the chart of the MEI, with red indicating El Ninos and blue La Ninas.:

Extended Multivariate ENSO Index

https://www.esrl.noaa.gov/psd/enso/mei.ext/

As we can see, the period 1925 to 1945 was dominated by powerful El Ninos. This of course was also the time of great warming in the Arctic, known as “The Warming in The North”, when temperatures across much of the Arctic were as high as they are now.

During the 1950s, a much colder climate took over in the Arctic, until it became warmer again in the 90s. This was also a period when La Ninas dominated.

Coincidence?

The climate in the Arctic is also very well correlated with the Atlantic Multidecadal Oscillation (AMO):

Continuer la lecture de El Nino & Arctic Warming In the 1930s →

biology+acidification, climate-debate

Coral tells own tale about El Niño’s past

by Rice University, March 27, 2020 in WUWT

HOUSTON – (March 26, 2020) – There is no longer a need to guess what ocean temperatures were like in the remote tropical Pacific hundreds of years ago. The ancient coral that lived there know all.

A study in Science led by Rice University and Georgia Tech researchers parses the record archived by ancient tropical Pacific coral over the past millennium. That record could help scientists refine their models of how changing conditions in the Pacific, particularly from volcanic eruptions, influence the occurrence of El Niño events, which are major drivers of global climate.

They found the ratio of oxygen isotopes sequestered in coral, an accurate measure of historic ocean temperatures, shows no correlation between estimates of sulfate particles ejected into the atmosphere by tropical volcanic eruptions and El Niño events.

That result could be of particular interest to scientists who suggest seeding the atmosphere with sun-blocking particles may help reverse global warming.

According to Rice climate scientist and primary author Sylvia Dee, previous climate model studies often tie volcanic eruptions, which increase sulfate aerosols in the atmosphere, to increased chances for an El Niño event. But the ability to analyze climate conditions based on oxygen isotopes trapped in fossil corals extends the climatological record in this key region across more than 20 ancient eruptions. Dee said this allows for a more rigorous test of the connection.

“A lot of climate modeling studies show a dynamical connection where volcanic eruptions can initiate El Niño events,” Dee said. “We can run climate models many centuries into the past, simulating volcanic eruptions for the last millennium.

“But the models are just that — models — and the coral record captures reality.”

Coral data that Georgia Tech climate scientist Kim Cobb and her team arduously collected on trips to the Pacific show little connection between known volcanoes and El Niño events over that time. Like tree rings, these paleoclimate archives hold chemical indicators, the oxygen isotopes, of oceanic conditions at the time they formed.

The coral data yields a high-fidelity record with a resolution of less than a month, tracking the El Niño-Southern Oscillation (ENSO) in the heart of the central tropical Pacific.

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climate-debate

New 80-Year Deep-Ocean Temperature Dataset Compared to a 1D Climate Model

by Roy Spencer, January 15, 2020 in WUWT/Ch.Rotter

The increasing global ocean heat content (OHC) is often pointed to as the most quantitative way to monitor long-term changes in the global energy balance, which is believed to have been altered by anthropogenic greenhouse gas emissions. The challenge is that long-term temperature changes in the ocean below the top hundred meters or so become exceedingly small and difficult to measure. The newer network of Argo floats since the early 2000s has improved global coverage dramatically.

A new Cheng et al. (2020) paper describing record warm ocean temperatures in 2019 has been discussed by Willis Eschenbach who correctly reminds us that such “record setting” changes in the 0-2000 m ocean heat content (reported in Zettajoules, which is 10^^21 Joules) amount to exceedingly small temperature changes. I calculate from their data that 2019 was only 0.004 0.009 deg. C warmer than 2018.

Over the years I have frequently pointed out that the global energy imbalance (less than 1 W/m2) corresponding to such small rates of warming is much smaller than the accuracy with which we know the natural energy flows (1 part in 300 or so), which means Mother Nature could be responsible for the warming and we wouldn’t even know it.

The Cheng (2017) dataset of 0-2000m ocean heat content changes extends the OHC record back to 1940 (with little global coverage) and now up through 2019. The methodology of that dataset uses optimum interpolation techniques to intelligently extend the geographic coverage of limited data. I’m not going to critique that methodology here, and I agree with those who argue creating data where it does not exist is not the same as having real data. Instead I want to answer the question:

If we take the 1940-2019 global OHC data (as well as observed sea surface temperature data) at face value, and assume all of the warming trend was human-caused, what does it imply regarding equilibrium climate sensitivity (ECS)?

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Fig. 1. Deep-ocean temperature variations 1940-2019 explained with a 2-layer energy budget model forced with RCP6 radiative forcing scenario and a model climate sensitivity of 1.85 deg. C. The model also matches the 1940-2019 and 1979-2019 observed sea surface temperature trends to about 0.01 C/decade. If ENSO effects are not included in the model, the ECS is reduced to 1.7 deg. C.

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climate-debate

Weak El Nino Conditions Help Explain Recent Global Warmth

by Dr. Roy Spencer,  January 13, 2020 in WUWT

The continuing global-average warmth over the last year has caused a few people to ask for my opinion regarding potential explanations. So, I updated the 1D energy budget model I described a couple years ago here with the most recent Multivariate ENSO Index (MEIv2) data. The model is initialized in the year 1765, has two ocean layers, and is forced with the RCP6 radiative forcing scenario and the history of El Nino and La Nina activity since the late 1800s.

The result shows that the global-average (60N-60S) ocean sea surface temperature (SST) data in recent months are well explained as a reflection of continuing weak El Nino conditions, on top of a long-term warming trend.

Fig. 1. 1D model of global ocean temperatures compared to observations. The model is forced with the RCP6 radiative forcing scenario (increasing CO2, volcanoes, anthropogenic aerosols, etc.) and the observed history of El Nino and La Nina since the late 1800s. The observations are monthly running 3-month averages and are offset with a single bias to match the model temperatures, which are departures from assumed energy equilibrium in 1765.

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unclassified

Half of 21st Century Warming Due to El Nino

by Roy Spencer, May 13, 2019 in GlobalWarming

A major uncertainty in figuring out how much of recent warming has been human-caused is knowing how much nature has caused. The IPCC is quite sure that nature is responsible for less than half of the warming since the mid-1900s, but politicians, activists, and various green energy pundits go even further, behaving as if warming is 100% human-caused.

The fact is we really don’t understand the causes of natural climate change on the time scale of an individual lifetime, although theories abound. For example, there is plenty of evidence that the Little Ice Age was real, and so some of the warming over the last 150 years (especially prior to 1940) was natural — but how much?

The answer makes as huge difference to energy policy. If global warming is only 50% as large as is predicted by the IPCC (which would make it only 20% of the problem portrayed by the media and politicians), then the immense cost of renewable energy can be avoided until we have new cost-competitive energy technologies.

The recently published paper Recent Global Warming as Confirmed by AIRSused 15 years of infrared satellite data to obtain a rather strong global surface warming trend of +0.24 C/decade. Objections have been made to that study by me (e.g. here) and others, not the least of which is the fact that the 2003-2017 period addressed had a record warm El Nino near the end (2015-16), which means the computed warming trend over that period is not entirely human-caused warming.

If we look at the warming over the 19-year period 2000-2018, we see the record El Nino event during 2015-16 (all monthly anomalies are relative to the 2001-2017 average seasonal cycle):

 

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better to know...?, climate-debate

Ouragans en Atlantique : prévisions pour la saison 2019

by Regis Crepet, 2 juin 2019 in LaChaîneMétéo

Ces deux dernières années ont été marquées par une activité cyclonique supérieure aux moyennes statistiques en Atlantique Nord, notamment en 2017 avec des phénomènes puissants tels Irma et Maria dans les Caraïbes. Cette année, alors que la saison démarre officiellement le 1er juin, nos prévisions sont plus rassurantes avec la perspective d’une activité cyclonique légèrement plus faible que la moyenne.

 

En ce début d’été météorologique, la saison cyclonique débute dans l’Atlantique nord (les ouragans). Cette saison s’étend officiellement du 1er juin au 30 novembre, avec un pic d’activité d’août à octobre. Il est donc l’heure pour les différents organismes météo de la planète et les météorologues et climatologues de La Chaîne Météo de se pencher sur les prévisions de cette saison à venir.

En 2017, la saison dans l’océan Atlantique nord a figuré parmi les plus actives depuis le début des relevés, avec des phénomènes dévastateurs (Harvey, Irma ou encore Maria dans les Caraïbes). Comme 2017, la saison 2018 s’est située au-dessus des moyennes (calculées par la NOAA d’après la période 1981/2010). Cette dernière saison a présenté, pour l’Atlantique nord, 15 phénomènes cycloniques, avec 8 ouragans dont 2 qui ont atteint la catégorie 3 sur 5, qualifiés alors de “majeurs”.

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climate-debate

2019 Atlantic hurricane forecast

by J. Curry and J. Johnstone, June4, 2019 in ClimateEtc.

CFAN predicts an active North Atlantic hurricane season season.

The Atlantic hurricane has begun.  We are off to an early start with one wimpy subtropical storm that lasted less than a day, and a small system that is trying to spin up in the Bay of Campeche.

Other forecast providers have begun issuing forecasts:

  • NOAA predicts a near normal season with 4-8 hurricanes.
  • Tropical Storm Risk predicts slightly below normal activity, with 6 hurricanes and ACE of 88.
  • Colorado State University predicts near normal season:  6 hurricanes and ACE of 100

Climate Forecast Applications Network (CFAN) is going bold, see below. [link] to forecast report.

CFAN’s seasonal forecast

Table 1. Current (May) 2019 hurricane forecasts of North Atlantic ACE, North Atlantic total hurricanes, U.S. landfalling hurricanes. 

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better to know...?, climate-debate

NOAA predicts near-normal 2019 Atlantic hurricane season

by Anthony Watts, May 23, 2019 in WUWT

El Nino and warmer-than-average Atlantic help shape this season’s intensity

From NOAA press release:

NOAA’s Climate Prediction Center is predicting that a near-normal Atlantic hurricane season is most likely this year. This outlook forecasts a 40% chance of a near-normal season, a 30% chance of an above-normal season and a 30% chance of a below-normal season. The hurricane season officially extends from June 1 to November 30.

For 2019, NOAA predicts a likely range of 9 to 15 named storms (winds of 39 mph or higher), of which 4 to 8 could become hurricanes (winds of 74 mph or higher), including 2 to 4 major hurricanes (category 3, 4 or 5; with winds of 111 mph or higher). NOAA provides these ranges with a 70% confidence. An average hurricane season produces 12 named storms, of which 6 become hurricanes, including 3 major hurricanes.

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