Archives par mot-clé : Temperature

Data From 2 Independent Studies Show No Correlation Between CO2 And Temperature

by P. Gosselin, July 29, 2020 in NoTricksZone


German climatologist Professor Dr. Horst-Joachim Lüdecke recently took data from two independent studies and superimposed them. The result shows  the long claimed atmospheric CO2-global temperature correlation doesn’t exist. 

The first data set was global temperature anomaly going back 600 million years, taken from the results of a paper by Came and Veizer, appearing in Nature (2007) and plotted below (blue):

The second data set was of atmospheric CO2 going back 600 million years, taken from a published study by Berner (2003), also appearing in Nature. These data are plotted in the above chart in blue.

No correlation

The plots were combined in the above chart to see how well they correlated, if at all. The result: no correlation.

For example, as the chart shows, 150 million years ago the atmospheric CO2 concentration was over 2000 ppm, which is 5 times today’s atmospheric concentration of 410 ppm – a level that some climate scientists say is already “dangerously high”. Yet, the global temperature 150 million years ago was more than 2°C below the long-term mean.

450 million years ago the relationship was even far more on its head: atmospheric CO2 concentrations were more than 10 times today’s level, yet the global temperature was a frigid 3.5°C below the mean!

“There’s no correlation between earth temperature and CO2,” Prof. Lüdecke concludes, observing recorded data.

Modern Ancient Temperatures

by W. Eschenbach, July 24, 2020 in WUWT


OK, no need to torture me, I confess it—I’m a data junkie.

And when I see a new (to me at least) high-resolution dataset, my knees get weak. Case in point? The temperature dataset of the Colle Gnifetti ice core. It has a two-year resolution thanks to some new techniques. Better, it stretches clear back to the year 800. And best, it extends up to near the present, 2006. This lets us compare it to modern datasets. The analysis of the ice core dataset is described in Temperature and mineral dust variability recorded in two low-accumulation Alpine ice cores over the last millennium by Pascal Bohleber et al.

Let me start with where Colle Gnifetti is located. Unusual among ice core records, it’s from Europe, specifically in the Alps on the border of Switzerland and Italy.

Figure 1. Location of the ice cores in the study.

This is good because some of the longest thermometer-based temperature records are in Europe.

One interesting thing about the site is that usually, ice core drilling occurs at the literal ends of the earth, in Antarctica and Greenland and the like. But this site is not far from the foot of the Margherita Hut, which is at over 4500 metres elevation.

 

Further Reading: It’s instructive to compare the listed temperatures with the data in A Chronological Listing of Early Weather Events.

Settled Science? New Climate Study Shifts the Goalposts to 2.6-3.9C

by Eric Worall, July 24, 2020 in WUWT


A new climate study has dismissed utterly implausible high end climate models. But the new study also seeks to raise the low end of the range of estimated climate sensitivity into the discomfort zone.

The treatment of cloud feedback is interesting. The study acknowledges large cloud feedback uncertainties, mentions the Lindzen et al. (2001) “iris effect”, and admits GCMs cannot be trusted to reproduce observed cloud response, yet still appears to attempt to derive a cloud feedback factor based on satellite observations, and mix this observational cloud factor with model predictions.

The treatment of clouds may turn out to be one of the most controversial assumptions in the study – as Pat Frank has pointed out on a number of occasions, the magnitude of model cloud response error is significantly greater than the CO2 driven warming which models attempt to project, which calls into question whether climate models have any predictive skill whatsoever.

To the author’s credit they have described their method in great detail, so I’m looking forward to detailed responses to this study.

Persistent warm Mediterranean surface waters during the Roman period

by Margaritelli G. et al., June20, 2020 in Nature OPEN ACESS


Abstract

Reconstruction of last millennia Sea Surface Temperature (SST) evolution is challenging due to the difficulty retrieving good resolution marine records and to the several uncertainties in the available proxy tools. In this regard, the Roman Period (1 CE to 500 CE) was particularly relevant in the socio-cultural development of the Mediterranean region while its climatic characteristics remain uncertain. Here we present a new SST reconstruction from the Sicily Channel based in Mg/Ca ratios measured on the planktonic foraminifer Globigerinoides ruber. This new record is framed in the context of other previously published Mediterranean SST records from the Alboran Sea, Minorca Basin and Aegean Sea and also compared to a north Hemisphere temperature reconstruction. The most solid image that emerges of this trans-Mediterranean comparison is the persistent regional occurrence of a distinct warm phase during the Roman Period. This record comparison consistently shows the Roman as the warmest period of the last 2 kyr, about 2 °C warmer than average values for the late centuries for the Sicily and Western Mediterranean regions. After the Roman Period a general cooling trend developed in the region with several minor oscillations. We hypothesis the potential link between this Roman Climatic Optimum and the expansion and subsequent decline of the Roman Empire.

See also  Roman Warm Period Was 3.6°F Warmer Than Today, New Study Shows

 See also here (GWPF)

Climate Models: No Warming For 30 Years – Possibly

by Maher et al., May 12, 2020 in GWPF


A new study demonstrates how a prolonged warming pause or even global cooling may happen in coming years despite increasing levels of atmospheric greenhouse gases — caused by natural climatic variability.

Natural climatic variability has always been a topic that contains a lot of unknowns, but it has been rarely explicitly stated just how little we know about it. Such variability has been habitually underplayed as it was “obvious” that the major driver of global temperature was the accumulation of greenhouse gasses in the atmosphere, with natural variability a weaker effect.

But the global temperature data of this century demonstrate that natural variability has dominated in the form of El Ninos. ‘Doesn’t matter’, came the reply, ‘just wait and the signal of greenhouse warming will emerge out of the noise of natural climatic variability.’ How long will we have to wait for that signal? Quite a long time, according to some researchers as more papers acknowledge that natural climatic variability has a major, if not a dominant influence on global temperature trends.

With the usual proviso concerning climatic predictions there seems to be a growing number of research papers suggesting that the global average temperature of at least the next five years will remain largely unchanged. The reason: natural climatic variability.

Only last week the UK Met Office produced figures suggesting that there is only a 1 in 34 chance that the 1.5°C threshold will be exceeded for the next five year period. Now a new paper by climate modellers extends such predictions, suggesting that because of natural variability the average global temperature up to 2049 could remain relatively unchanged – even with the largest increase in greenhouse gas emissions.

Using two types of computer models in a first of its kind study, Nicola Maher of the Max Planck Institute for Meteorology, Hamburg, Germany, and colleagues writing in Environmental Research Letters looked at the 2019-2034 period concluding that,

Atmospheric CO2 during the Mid-Piacenzian Warm Period and the M2 glaciation

by de la Vega et al., 2020 in Nature OPEN  ACCESS


Abstract

The Piacenzian stage of the Pliocene (2.6 to 3.6 Ma) is the most recent past interval of sustained global warmth with mean global temperatures markedly higher (by ~2–3 °C) than today. Quantifying CO2 levels during the mid-Piacenzian Warm Period (mPWP) provides a means, therefore, to deepen our understanding of Earth System behaviour in a warm climate state. Here we present a new high-resolution record of atmospheric CO2 using the δ11B-pH proxy from 3.35 to 3.15 million years ago (Ma) at a temporal resolution of 1 sample per 3–6 thousand years (kyrs). Our study interval covers both the coolest marine isotope stage of the mPWP, M2 (~3.3 Ma) and the transition into its warmest phase including interglacial KM5c (centered on ~3.205 Ma) which has a similar orbital configuration to present. We find that CO2 ranged from 389+388389−8+38ppm to 331+1311,331−11+13,ppm, with CO2 during the KM5c interglacial being 371+3229371−29+32ppm (at 95% confidence). Our findings corroborate the idea that changes in atmospheric CO2 levels played a distinct role in climate variability during the mPWP. They also facilitate ongoing data-model comparisons and suggest that, at present rates of human emissions, there will be more CO2 in Earth’s atmosphere by 2025 than at any time in at least the last 3.3 million years.

Carbon dioxide level unprecedented in 15 MY… More evidence it’s not the climate control knob!avid Middl

by David Middleton, July 10, 2020 in WUWT


If the Earth was 3-4 °C warmer with a much higher sea level 3.3 million years ago, with about the same CO2 concentration, what does this say about the potency of it as a climate control knob?

The last time CO2 levels were this low, Earth was in the deepest ice age of the Phanerozoic Eon, the Pennsylvanian (Late Carboniferous)-Early Permian.

Figure 5. Phanerozoic temperatures (pH-corrected) and carbon dioxide. The Miocene is the first epoch of the Neogene Period (Berner et al, 2001 and Royer et al., 2004) (older is toward the left).

HIGHEST U.S. TEMPERATURES ON RECORD BY STATE

by Cap Allon, July 12, 2020 in Electroverse


Historical documentation destroys the man-made global warming theory.

While those in control of the temperature graphs are all too happy to fraudulently increase the running average, what they haven’t (yet) had the balls to do is rewrite the history books.

As Tony Heller uncovers on his site realclimatescience, NASA routinely cools the past and heats the present, so to give the illusion of a greater warming trend — and comparisons between old and new graphs instantly reveals this fraud:

In 1999, NASA’s James Hansen reported 0.5C US cooling since the 1930’s:

By 2016, the same NASA graph has eliminated that 1930-1999 cooling:

Arctic Ocean changes driven by sub-Arctic seas

by University of Alaska Fairbank, July 12, 2020 in WUWT


New research explores how lower-latitude oceans drive complex changes in the Arctic Ocean, pushing the region into a new reality distinct from the 20th-century norm.

The University of Alaska Fairbanks and Finnish Meteorological Institute led the international effort, which included researchers from six countries. The first of several related papers was published this month in Frontiers in Marine Science.

Climate change is most pronounced in the Arctic. The Arctic Ocean, which covers less than 3% of the Earth’s surface, appears to be quite sensitive to abnormal conditions in lower-latitude oceans.

“With this in mind, the goal of our research was to illustrate the part of Arctic climate change driven by anomalous [different from the norm] influxes of oceanic water from the Atlantic Ocean and the Pacific Ocean, a process which we refer to as borealization,” said lead author Igor Polyakov, an oceanographer at UAF’s International Arctic Research Center and FMI.

Although the Arctic is often viewed as a single system that is impacted by climate change uniformly, the research stressed that the Arctic’s Amerasian Basin (influenced by Pacific waters) and its Eurasian Basin (influenced by Atlantic waters) tend to differ in their responses to climate change.

Since the first temperature and salinity measurements taken in the late 1800s, scientists have known that cold and relatively fresh water, which is lighter than salty water, floats at the surface of the Arctic Ocean. This fresh layer blocks the warmth of the deeper water from melting sea ice.

IMAGE: A MAP OF THE ARCTIC OCEAN SHOWS THE LOCATION OF THE AMERASIAN AND EURASIAN BASINS. ARROWS SHOW THE PATH OF WARM, FRESH PACIFIC WATER AND WARM, SALTY ATLANTIC WATER INTO… view more CREDIT: GRAPHIC ADAPTED FROM POLYAKOV ET AL. 2020, FRONTIERS IN MARINE SCIENCE PAPER.

Flawed Models: New Studies Find Plants Take Up “More Than Twice As Much” CO2 Than Expected

by Fritz Vahrenholt, July 7, 2020 in NoTricksZone


First, the global mean temperature of satellite based measurements was surprisingly much higher in May 2020 than in April. In contrast, the global temperatures of the series of measurements on land and sea decreased. The difference can be explained by the fact that under warm El-Nino conditions the satellite measurements lag about 2-3 months behind the earth-based measurements.

From November 2019 to March 2020 a moderate El-Nino was observed, which has now been replaced by neutral conditions in the Pacific. Therefore, it is to be expected that also the satellite based measurements, which we use at this point, will show a decrease in temperatures within 2-3 months.

The average temperature increase since 1981 remained unchanged at 0.14 degrees Celsius per decade. The sunspot number of 0.2 corresponded to the expectations of the solar minimum.

The earth is greening

DESPITE THE LIES, THE SPIN, AND THE PROPAGANDA, ANTARCTIC SEA ICE IS GROWING — BOTH EXTENT AND CONCENTRATION GREATER NOW THAN IN 1980

by Cap Allon, July 6, 2020 in Electroverse


The UN and their scraggly little offshoot, the IPCC, are at it again — obfuscating data in order to push their fraudulent catastrophic global warming agenda.

According to the IPCC, and picked up the usual AGW propaganda rags such as the Guardian: “the South pole is warming three times faster than rest of the world.”

The Guardian articledated June 30, 2020 continues in predictably befogging fashion: “Dramatic change in Antarctica’s interior in past three decades a result of effects from tropical variability working together with increasing greenhouse gases.”

But, 1) the MSM have a habit of claiming everywhere is warming faster than everywhere else:

And 2), the actual data reveals quite the opposite re Antarctica.

As @Harry_Hardrada recently pointed out on Twitter, there was a larger extent and concentration of Antarctic Sea Ice in June 2020 than back in June 1980:

Robert Felix over at iceagenow.com dives into the data, adding that sea ice extent today stands at 700,000 sq km (270,272 sq miles) greater than in 1980.

And in case you’re having a hard time reading the numbers, Felix breaks them down for you:

Sea ice extent in June 2020 = 13.2 million sq km
Sea ice extent in June 1980 = 12.5 million sq km

Sea ice concentration in June 2020 = 10.6 million sq km
Sea ice concentration in June 1980 = 9.6 million sq km

Fact-checked!

That’s enough extra ice to entirely cover Maryland, Delaware, West Virginia, South Carolina, Virginia, Indiana, Ohio and all six New England states. Oh, and throw in Washington, D.C. for good measure. (Which might be a good idea.)

 See also THE ARCTIC IS ON FIRE, AND WE SHOULD ALL BE TERRIFIED” — FACT CHECK: IT’S CURRENTLY SNOWING IN VERKHOYANSK

Extensive hake (fish) skeletal remains in ocean waters too cold for this species to occupy today suggest past ocean temperatures were several degrees warmer.

by Wheeland & Morgan, July 2020 in NoTricksZone


Fish habitats are limited by specific temperature boundaries. In a new study, for example,  Wheeland  and Morgan (2020) found there was a pronounced ocean warming from the 1980s to late 1990s off the coasts of Greenland. This temperature shift changed the distribution of halibut habitat. Since then, however, there has been no net warming in the study region (through 2016).

CLAIM: 100 degrees in Siberia? 5 ways the extreme Arctic heat wave follows a disturbing pattern

by C. Rotter, June 28, 2020 in WUWT


This essay from director of NSIDC, Mark Serreze, is provided for reference. You may remember Serreze who once said “the Arctic is screaming” while botching and then backpedaling on claims of “ice free summers” on the near horizon for the Arctic that never happened. Give it all the consideration it is due. For some perspective, see my article on a previous 100 degree event above the Arctic circle over 100 years ago. By the way, with 24 hours daylight above the Arctic circle, and near 24 hour daylight in Siberia this time of year, (the first day of summer aka  the summer solstice) is it any surprise it would get warm?

This Arctic heat wave has been unusually long-lived. The darkest reds on this map of the Arctic are areas that were more than 14 degrees Fahrenheit warmer in the spring of 2020 compared to the recent 15-year average. Joshua Stevens/NASA Earth Observatory

Siberian Heatwave–Climate Or Weather?

by P. Homewood, June 27, 2020 in NotaLotofPeoppleKnowThat


The Conversation has now got involved in the Arctic heatwave scare, with this article by Jonathan Bamber, Professor of Physical Geography, University of Bristol :

On the eve of the summer solstice, something very worrying happened in the Arctic Circle. For the first time in recorded history, temperatures reached 38°C (101°F) in a remote Siberian town – 18°C warmer than the maximum daily average for June in this part of the world, and the all-time temperature record for the region.

New records are being set every year, and not just for maximum temperatures, but for melting ice and wildfires too. That’s because air temperatures across the Arctic have been increasing at a rate that is about twice the global average.

All that heat has consequences. Siberia’s recent heatwave, and high summer temperatures in previous years, have been accelerating the melting of Arctic permafrost. This is the permanently frozen ground which has a thin surface layer that melts and refreezes each year. As temperatures rise, the surface layer gets deeper and structures embedded in it start to fail as the ground beneath them expands and contracts. This is what is partly to blame for the catastrophic oil spill that occurred in Siberia in June 2020, when a fuel reservoir collapsed and released more than 21,000 tonnes of fuel – the largest ever spill in the Arctic.

So what is wrong with the Arctic, and why does climate change here seem so much more severe compared to the rest of the world?

https://theconversation.com/siberia-heatwave-why-the-arctic-is-warming-so-much-faster-than-the-rest-of-the-world-141455

Scientists Panic, Because Arctic Is 0.4F Warmer Than In 1915!

by P. Homewood, June 21, 2020 in NotaLotofPeopleKnowThat


The Arctic is thought to have recorded its hottest ever temperature of 100.4F (38C) in Siberia, an astonishing 32F (18C) above the normal level for this time of year.

The mercury shot up to the unprecedented level in Verkhoyansk, 3,000 miles east of Moscow, as the region endures a summer heatwave.

Scientists had predicted the Arctic wouldn’t reach these levels until 2100, meaning it is warming 80 years faster than previously thought.

If the record is confirmed it will represent a new high. The current record for hottest temperature in the Arctic is held by Prospect Creek, Alaska, which recorded 100F (38C) in 1915.

Weatherman for CBS, Jeff Beradelli, said on Twitter yesterday: ‘Likely the hottest temperature ever recorded in the Arctic happened today.

‘What’s happening in Siberia this year is nothing short of remarkable. For perspective, Miami has only reached 100F (38C) once on record.’

https://www.dailymail.co.uk/news/article-8444319/Arctic-records-hottest-temperature-mercury-hits-100F-town-Verkhoyansk-Siberia.html?login#readerCommentsCommand-message-field

 

Even the babies who write for the Mail could surely spot the fly in the ointment – that this new record is only 0.4F higher than the previous one set in 1915! Hardly the apocalypse they are trying to present.

As for Verkhoyansk itself, temperatures there reached 37.3C (99.1F) in 1988 during a succession of 30C+ days, so again there is nothing remarkable about the latest weather at all :

What Happened To Greenland’s Tipping Point?

by P. Homewood, June 22, 2020 in NotaLotofPeopleKnowThat


Ten years ago, the Guardian warned us that Greenland would have passed a tipping point by now, with the whole ice sheet due to disappear by the end of the century:

How did that work out then?

The article was written in 2010, which was the warmest on record. Since then, however, Greenland’s temperatures have returned to normal, and are no higher than they were in the 1930s.

Far from being the start of a new trend, 2010 was simply an outlier:

 

British Columbia Breaks Cold And Snow Records

by Cap Allon, June 15, 2020 in ClimateChangeDispatch


Record cold and late-spring snow helped drive-home the Grand Solar Minimum message across the BC Interior over the weekend.

According to KelownaNow Meteorologist Wesla English, the Interior –one of the three main regions of the Canadian province of British Columbia– broke a slew of cold records on Saturday.

Kelowna, Kamloops, Clearwater, Penticton, Salmon Arm, and Vernon were among the areas to set new all-time record low-max temperatures for June 13.

“A cool upper low over Southern BC produced chilly temperatures on Saturday, breaking record low daytime highs in several areas,” wrote English.

Below is a breakdown of the records (data courtesy of Environment and Climate Change Canada, and originally reported by kelownanow.com):

  • Kelowna set a new daily record min-high of 12.8C on Saturday, a reading comfortably topping the previous record of 13.3C set in 1981.
  • Kamloops saw its all-time record low smashed, from 1923’s 15C to this weekend’s 13.4C.
  • But it was Salmon Arm that actually saw the biggest change — Saturday’s low-max of 12.4Ccrushed the old record of 14.4C from 1971.
  • Clearwater’s12.8C busted the 13.3C from 1966.
  • While the 13.9C set at Penticton pipped the previous record — 1981’s 14C.

In addition to the cold, this weekend delivered rare late-spring snow to BC, adding to Ontario’s record June snowfall last weekend that brought power outages to parts of the province.

Wet snow accumulated near the summit of the Okanagan Connector between Merritt and Kelowna on Sunday,

See also BOTH KELOWNA AND SUMMERLAND BUST 108-YEAR-OLD COLD RECORDS

DWD Reverses: Admits Data From Germany’s Infamous Ultra-Hot Lingen Weather Station Need To Be Rechecked

by P. Gosselin, June10, 2020 in NoTricksZone


Recently I wrote here how Germany’s now infamous record-setting weather station in Lingen was producing readings that were 2-3°C hotter than surrounding stations, yet the German DWD weather service refused to acknowledge the station was likely producing bad data. Today they admit the station has problems and that they will be moving it to a better location.

Last year’s all-time record high is now in question.

Lingen’s heated readings

Last summer the Lingen station, located in northwest Germany near the Dutch border, smashed the country’s all-time record high when the ‘mercury’ rose to a scorching 42.6°C during a late July heat wave. The previous all-time high for Germany was a comparatively cool 40.3°C.

 

Lingen’s readings of late July 2019 compared to other stations in the surrounding region (July 23 – July 27).

BBC’s Fake Claim About “Hottest May”

by P. Homewood, June 5, 2020 in NotaLotofPeopleKnowThat


I make no comment about the global numbers, but would simply point out that none of the official agencies have released their data for May. The BBC claim comes from Copernicus, the EU agency, not regarded as a reliable source.

However the BBC claim about the UK is hopelessly wide of the mark. According to the Met Office, last month was only the 15th warmest May since 1884, and was not even as warm as 1893 and 1911!

https://www.metoffice.gov.uk/research/climate/maps-and-data/uk-temperature-rainfall-and-sunshine-time-series

Such sloppy reporting is only too common at the BBC, and not just where climate change is concerned. It only takes a minute to find the Met Office data, and I find it hard to understand why the programme editors did not think it worthwhile checking such an outlandish claim first.

Needless to say, I have filed a complaint, to add to the list of BBC climate lies!!

 

Sunny May–But Only The 48th Warmest

by P. Homewood, June 3, 2020 in NotaLotofPeopleKnowThat


While we’re on with Harrabin’s hysterics about May’s sunny weather being due to climate change, it is appropriate to point out to him that last month was far from being the hottest on record in England:

https://www.metoffice.gov.uk/hadobs/hadcet/data/download.html

 

In fact there have been 47 hotter Mays since 1659. The hottest was 1833, and the five hottest were all pre 1850.

See also:  UAH Global Temperature Update for May 2020: +0.54 deg. C

WASHINGTON, D.C. JUST SUFFERED ITS COLDEST MAY SINCE 2005

by Cap Allon, June 2, 2020 in Electroverse


Like April, May was cooler than average across the District,” admits filthy warm-mongers the washingtonpost.com in a recent article. The month officially logged an average temperature of just 63.8F, which is 2.2F below the 30-year average, and made for Washington’s coldest May in 15 years.

The average temperature more closely matched a typical May in New York City, points out the Southeast Regional Climate Center. And with NYC located some 200 miles north of Washington, May 2020 serves as a great illustration of how the GSM is driving the COLD LINE south.

The past two months also marked the first time since 2003 that both April and May were colder than average across the District.

In addition, May 9’s daily high of 52F was the lowest-high during the month of May since May 12, 2008 (solar minimum of cycle 23), and the chill even brought a few snow flurries to Washington’s far north and west suburbs. That 52F on May 9 also matched the record lowest-high for the date which was set way back in 1877 (solar minimum of cycle 11).

Many more all-time cold-records fell across the District that day; including Dulles smashing its record for min-high from 1977 (solar minimum of cycle 20), and Baltimore toppling both its all-time min-low from 1966 (solar minimum of cycle 19) as well as its min-high set back in 1977 (solar min of cycle 20)and 1947 (solar min of cycle 17).

Germany’s DWD National Weather Service Denies Station Siting Problem: “Dubious” All-Time Record Temperature Allowed To Stand

by P. Gosselin, May 26, 2020 in NoTricksZone


Leading German daily Bild here reports on the controversy, which still continues to swirl, over Germany’s all-time record high temperature recorded last year in North Germany near the Dutch border.

Independent meteorologists say the readings needs to be thrown out

Last year on July 25th, the Lingen thermometer reached a whopping 42.6°C, far eclipsing the old German all-time record of 40.3°C. But that recording quickly came under fire by independent weather experts who say the station data were  corrupted by siting issues. The Lingen station is located in a depression in the earth, near a parking lot, and shielded by trees from the wind, thus creating the ideal conditions for trapping heat.

Comparison to nearby stations shows huge anomaly

Last year NTZ reported on the controversial record here noting that surrounding stations did not even come close to record reading in Lingen. What follows is a comparison of the Lingen’s readings to those of 6 nearby stations over the five day period, July 23 – July 27:

Tendencies, variability and persistence of sea surface temperature anomalies

by Bulgin et al., May 14, 2020 in Nature OPEN ACCESS


Abstract

Quantifying global trends and variability in sea surface temperature (SST) is of fundamental importance to understanding changes in the Earth’s climate. One approach to observing SST is via remote sensing. Here we use a 37-year gap-filled, daily-mean analysis of satellite SSTs to quantify SST trends, variability and persistence between 1981–2018. The global mean warming trend is 0.09 K per decade globally, with 95% of local trends being between −0.1 K and + 0.35 K. Excluding perennial sea-ice regions, the mean warming trend is 0.11 K per decade. After removing the long-term trend we calculate the SST power spectra over different time periods. The maximum variance in the SST power spectra in the equatorial Pacific is 1.9 K2 on 1–5 year timescales, dominated by ENSO processes. In western boundary currents characterised by an intense mesoscale activity, SST power on sub-annual timescales dominates, with a maximum variance of 4.9 K2. Persistence timescales tend to be shorter in the summer hemisphere due to the shallower mixed layer. The median short-term persistence length is 11–14 days, found over 71–79% of the global ocean area, with seasonal variations. The mean global correlation between monthly SST anomalies with a three-month time-lag is 0.35, with statistically significant correlations over 54.0% of the global oceans, and notably in the northern and equatorial Pacific, and the sub-polar gyre south of Greenland. At six months, the mean global SST anomaly correlation falls to 0.18. The satellite data record enables the detailed characterisation of temporal changes in SST over almost four decades.

 …