Presently sea surface temperatures (SST) are the best available indicator of heat content gained or lost from earth’s climate system.  Enthalpy is the thermodynamic term for total heat content in a system, and humidity differences in air parcels affect enthalpy.  Measuring water temperature directly avoids distorted impressions from air measurements.  In addition, ocean covers 71% of the planet surface and thus dominates surface temperature estimates.  Eventually we will likely have reliable means of recording water temperatures at depth.

Recently, Dr. Ole Humlum reported from his research that air temperatures lag 2-3 months behind changes in SST.  He also observed that changes in CO2 atmospheric concentrations lag behind SST by 11-12 months.  This latter point is addressed in a previous post Who to Blame for Rising CO2?

The August update to HadSST3 will appear later this month, but in the meantime we can look at lower troposphere temperatures (TLT) from UAHv6 which are already posted for August. The temperature record is derived from microwave sounding units (MSU) on board satellites like the one pictured above.

The UAH dataset includes temperature results for air above the oceans, and thus should be most comparable to the SSTs. There is the additional feature that ocean air temps avoid Urban Heat Islands (UHI).  The graph below shows monthly anomalies for ocean temps since January 2015.

Remarkably, the anomalies over the entire ocean dropped to the same value, 0.12C (Tropics are 0.13C).  In previous months both the Tropics and SH rose, while NH rose very slightly, resulting in a small increase in the Global average temp of air over oceans. Now that warming is gone in NH and Globally.

Taking a longer view, we can look at the record since 1995, that year being an ENSO neutral year and thus a reasonable starting point for considering the past two decades.  On that basis we can see the plateau in ocean temps is persisting. Since last October all oceans have cooled, with offsetting bumps up and down.

UAHv6 TLT  Monthly Ocean Anomalies	Average Since 1995	Ocean 8/2018
Global	0.13	0.12
NH	0.16	0.12
SH	0.11	0.12
Tropics	0.12	0.13

As of August 2018, Global ocean air temps as well as SH and Tropics are matching the average since 1995.  NH is now cooler than the average.  Globally,  2018 is the coolest August since 2013. NH, SH and the Tropics are the coolest August since 2014.

The details of UAH ocean temps are provided below.  The monthly data make for a noisy picture, but seasonal fluxes between January and July are important.

The greater volatility of the Tropics is evident, leading the oceans through three major El Nino events during this period.  Note also the flat period between 7/1999 and 7/2009.  The 2010 El Nino was erased by La Nina in 2011 and 2012.  Then the record shows a fairly steady rise peaking in 2016, with strong support from warmer NH anomalies, before returning to the 22-year average.

Summary

TLTs include mixing above the oceans and probably some influence from nearby more volatile land temps.  They started the recent cooling later than SSTs from HadSST3, but are now showing the same pattern.  It seems obvious that despite the three El Ninos, their warming has not persisted, and without them it would probably have cooled since 1995.  Of course, the future has not yet been written.

 

 

A previous post explored the claim that “Nunavut is melting” and is reproduced below.  On September 6 Jane George posted at the Northwest Passage blog declaring the opposite:  As ice and snow return, summer’s over in Nunavut  “It was a cold summer.”  Excerpts below in italics with my bolds.

This map from the Canadian Ice Service shows sea ice conditions in the western part of High Arctic islands on Sept. 8. The dark blue shows a low concentration (less than 10 per cent) of ice, while white shows a high concentration (100 per cent). At this time of the year, the Arctic ice cover is the highest it has been since 2014, the National Snow and Ice Data Center said Sept. 5.

Snow has now fallen across Nunavut’s more northerly communities, from Kugluktuk to Qikiqtarjuaq, after a summer that also brought cool temperatures and heavy ice conditions to some parts of Nunavut.

“if you’re trying to get somewhere, and ice is in the way, it’s been a very bad year,” said Gilles Langis, a senior ice forecaster with the Canadian Ice Service.

It remains unclear if ice played a role in the grounding of the Ioffe Akademik on Aug. 24. The cruise ship was not sailing where it was supposed to be due to ice, according to an account by the journalist and author Ed Struzik, who was on board.

And, earlier this week, operators of the cruise vessel Hanseatic turned around and headed back east through the Northwest Passage, having decided that ice conditions were too bad to continue on to western Nunavut.

The Canadian Coast Guard also recently rescued two sailors from a smaller vessel that had run into bad ice conditions in the Bellot Strait.

Summing up the summer ice conditions in 2018, Langis said that in many areas it was “very challenging”—in parts of Hudson Bay, Hudson Strait, Baffin Bay and at various choke points in the Northwest Passage where the ice pushed in.

Ice conditions are not likely to improve.  And as for the weather, it’s not likely not to be warming up either.

“It was a cold summer,” said Brian Proctor from Environment Canada. As well, northern Canada saw above normal precipitation in many communities because of a low pressure front stalled over the North.

Iqaluit experienced its 13th coldest and 14th wettest year in 73 years, he said.

In Qikiqtarjuaq, where snow also came early, it was the seventh coldest summer in 22 years.

Previous post:  Nunavut is Melting!  Or not.

From Yale Climate Connections we heard last week about Nunavut melting and a theatrical production to spread news and concerns about this dangerous development.

“I come from a place of rugged mountains, imperial glaciers and tender-covered permafrost. But Nunavut, our land, is only as rich as it is cold, and today most of it is melting.”That’s Chantal Bilodeau, reading a passage from “Sila,” a play about the effects of climate change in the Arctic.

The characters in her play include polar bears, an Inuit goddess, scientists, and coast guard officers – all working together to save their land.

No doubt her personal experience and feelings for her Nunavut are sincere and profound. (Originally I thought it was her homeland, but in fact she is a New York playwright and translator, born in Montreal.) And there will be a large audience receptive to her concerns about global warming. (Bilodeau has writen six plays about the Arctic and founded the international network Artists And Climate Change.) But I wonder if scientific measurements support her belief that Nunavut is melting.

After all, we have learned from medical research that individual life experiences (anecdotes) may not be true more generally. That is why drugs are tested on population samples with double-blind studies: neither the patient nor the doctor knows who gets the medicine and who gets the placebo.

So I went looking for weather station records to see what is the warming trend in that region. As curiosity does so often, it led me on a journey of discovery, learning some new things, and relearning old ones with fresh implications.

Where are temperatures measured in Nunavut?

It is by far the Northernmost territory of Canada, just off the coast of Northern Greenland.

According to Environment Canada, weather is reported at 29 places in Nunavut. So I went to look at the record at Iqaluit, the capital of the territory. You get monthly normals for the period 1981 to 2010. Historical data (daily averages) can be accessed only 1 individual month/year at a time, the menu stops at 2004. Even then, some months are filled with “M” for missing. Historical data from which trends can be analyzed is hard to come by.

Disappearing Weather Records

It turns out that Nunavut also suffered from the great purging of weather station records that was noticed by skeptics years ago.

I was aware of this because of a recent study looking at trends at stations around the Arctic circle. Arctic Warming Unalarming.  That study included graphs that showed the dramatic removal of station records in the North.  Though the depletion was not limited to the far North, many Canadian and Russian records disappeared from the global database.

Eureka, Nunavut, Canada “Last Station above latitude 65N”

Eureka got considerable attention in 2010 due to its surviving the dying out of weather stations. The phrase in quotes above reflects an observation that GISS uses Eureka data to infill across the whole Arctic Circle. That single station record is hugely magnified in its global impact in that temperature reconstruction product. Somewhat like the influence of a single tree in Yamal upon the infamous hockey stick graph.

The first High Arctic Weather Station in history, Eureka was established in April 1947 at 80-degrees north latitude in the vicinity of two rivers, which provided fresh water to the six-man United States Army Air Force team that parachuted in. They erected Jamesway huts to shelter themselves and their equipment until August, when an icebreaker reached Eureka – as it has every year since – and brought permanent buildings and supplies. For decades after that, small, all-male crews would hunker down for entire winters, going a little stir-crazy from the isolation. WUWT 2010

GHCN Records for Nunavut

It turns out that in addition to Eureka, GCHN has data for Alert and Clyde (River), but the latter two histories end in 2004 and 2010, respectively. The adjusted files have a few differences in details, but little change from the unadjusted files. The chart below shows the temperatures measured at Eureka, Nunavut, Canada 79° 98’ N, 85° 93’ W.  The other two stations tell the same story as Eureka, though temperatures at Clyde are warmer in absolute terms due to its more Southerly location.

The chart shows Annual, July and January averages along with the lifetime averages of Eureka station from 1948 through 2015.  There is slight variability, and a few years higher than average, but nothing alarming or even enough for people to sense any change.  Note also that annual averages are well below freezing, because only 3 months are above 0° C.  I suppose that someone could play with anomalies and generate a chart that looked scary, but the numbers in the record do not support fears of global warming and melting in Nunavut.

Conclusion

Once again we see media announcements that confuse subjective beliefs with empirical observations of objective reality.  And unfortunately, those observations are less and less available to counter the herd instincts of fearing the future and blaming someone.

 

Here is an analysis using critical intelligence to interpret media reports about temperature records this summer. Daniel Engber writes in Slate Crazy From the Heat

The subtitle is Climate change is real. Record-high temperatures everywhere are fake.  As we shall see from the excerpts below, The first sentence is a statement of faith, since as Engber demonstrates, the notion does not follow from the temperature evidence. Excerpts in italics with my bolds.

It’s been really, really hot this summer. How hot? Last Friday, the Washington Post put out a series of maps and charts to illustrate the “record-crushing heat.” All-time temperature highs have been measured in “scores of locations on every continent north of the equator,” the article said, while the lower 48 states endured the hottest-ever stretch of temperatures from May until July.

These were not the only records to be set in 2018. Historic heat waves have been crashing all around the world, with records getting shattered in Japan, broken on the eastern coast of Canada, smashed in California, and rewritten in the Upper Midwest. A city in Algeria suffered through the highest high temperature ever recorded in Africa. A village in Oman set a new world record for the highest-ever low temperature. At the end of July, the New York Times ran a feature on how this year’s “record heat wreaked havoc on four continents.” USA Today reported that more than 1,900 heat records had been tied or beaten in just the last few days of May.

While the odds that any given record will be broken may be very, very small, the total number of potential records is mind-blowingly enormous.

There were lots of other records, too, lots and lots and lots—but I think it’s best for me to stop right here. In fact, I think it’s best for all of us to stop reporting on these misleading, imbecilic stats. “Record-setting heat,” as it’s presented in news reports, isn’t really scientific, and it’s almost always insignificant. And yet, every summer seems to bring a flood of new superlatives that pump us full of dread about the changing climate. We’d all be better off without this phony grandiosity, which makes it seem like every hot and humid August is unparalleled in human history. It’s not. Reports that tell us otherwise should be banished from the news.

It’s true the Earth is warming overall, and the record-breaking heat that matters most—the kind we’d be crazy to ignore—is measured on a global scale. The average temperature across the surface of the planet in 2017 was 58.51 degrees, one-and-a-half degrees above the mean for the 20th century. These records matter: 17 of the 18 hottest years on planet Earth have occurred since 2001, and the four hottest-ever years were 2014, 2015, 2016, and 2017. It also matters that this changing climate will result in huge numbers of heat-related deaths. Please pay attention to these terrifying and important facts. Please ignore every other story about record-breaking heat.

You’ll often hear that these two phenomena are related, that local heat records reflect—and therefore illustrate—the global trend. Writing in Slate this past July, Irineo Cabreros explained that climate change does indeed increase the odds of extreme events, making record-breaking heat more likely. News reports often make this point, linking probabilities of rare events to the broader warming pattern. “Scientists say there’s little doubt that the ratcheting up of global greenhouse gases makes heat waves more frequent and more intense,” noted the Times in its piece on record temperatures in Algeria, Hong Kong, Pakistan, and Norway.

Yet this lesson is subtler than it seems. The rash of “record-crushing heat” reports suggest we’re living through a spreading plague of new extremes—that the rate at which we’re reaching highest highs and highest lows is speeding up. When the Post reports that heat records have been set “at scores of locations on every continent,” it makes us think this is unexpected. It suggests that as the Earth gets ever warmer, and the weather less predictable, such records will be broken far more often than they ever have before.

But that’s just not the case. In 2009, climatologist Gerald Meehl and several colleagues published an analysis of records drawn from roughly 2,000 weather stations in the U.S. between 1950 and 2006. There were tens of millions of data points in all—temperature highs and lows from every station, taken every day for more than a half-century. Meehl searched these numbers for the record-setting values—i.e., the days on which a given weather station saw its highest-ever high or lowest-ever low up until that point. When he plotted these by year, they fell along a downward-curving line. Around 50,000 new heat records were being set every year during the 1960s; then that number dropped to roughly 20,000 in the 1980s, and to 15,000 by the turn of the millennium.

This shouldn’t be surprising. As a rule, weather records will be set less frequently as time goes by. The first measurement of temperature that’s ever taken at a given weather station will be its highest (and lowest) of all time, by definition. There’s a good chance that the same station’s reading on Day 2 will be a record, too, since it only needs to beat the temperature recorded on Day 1. But as the weeks and months go by, this record-setting contest gets increasingly competitive: Each new daily temperature must now outdo every single one that came before. If the weather were completely random, we might peg the chances of a record being set at any time as 1/n, where n is the number of days recorded to that point. In other words, one week into your record-keeping, you’d have a 1 in 7 chance of landing on an all-time high. On the 100th day, your odds would have dropped to 1 percent. After 56 years, your chances would be very, very slim.

The weather isn’t random, though; we know it’s warming overall, from one decade to the next. That’s what Meehl et al. were looking at: They figured that a changing climate would tweak those probabilities, goosing the rate of record-breaking highs and tamping down the rate of record-breaking lows. This wouldn’t change the fundamental fact that records get broken much less often as the years go by. (Even though the world is warming, you’d still expect fewer heat records to be set in 2000 than in 1965.) Still, one might guess that climate change would affect the rate, so that more heat records would be set than we’d otherwise expect.

That’s not what Meehl found. Between 1950 and 2006, the rate of record-breaking heat seemed unaffected by large-scale changes to the climate: The number of new records set every year went down from one decade to the next, at a rate that matched up pretty well with what you’d see if the odds were always 1/n. The study did find something more important, though: Record-breaking lows were showing up much less often than expected. From one decade to the next, fewer records of any kind were being set, but the ratio of record lows to record highs was getting smaller over time. By the 2000s, it had fallen to about 0.5, meaning that the U.S. was seeing half as many record-breaking lows as record-breaking highs. (Meehl has since extended this analysis using data going back to 1930 and up through 2015. The results came out the same.)

What does all this mean? On one hand, it’s very good evidence that climate change has tweaked the odds for record-breaking weather, at least when it comes to record lows. (Other studies have come to the same conclusion.) On the other hand, it tells us that in the U.S., at least, we’re not hitting record highs more often than we were before, and that the rate isn’t higher than what you’d expect if there weren’t any global warming. In fact, just the opposite is true: As one might expect, heat records are getting broken less often over time, and it’s likely there will be fewer during the 2010s than at any point since people started keeping track.

This may be hard to fathom, given how much coverage has been devoted to the latest bouts of record-setting heat. These extreme events are more unusual, in absolute terms, than they’ve ever been before, yet they’re always in the news. How could that be happening?

While the odds that any given record will be broken may be very, very small, the total number of potential records that could be broken—and then reported in the newspaper—is mind-blowingly enormous. To get a sense of how big this number really is, consider that the National Oceanic and Atmospheric Administration keeps a database of daily records from every U.S. weather station with at least 30 years of data, and that its website lets you search for how many all-time records have been set in any given stretch of time. For instance, the database indicates that during the seven-day period ending on Aug. 17—the date when the Washington Post published its series of “record-crushing heat” infographics—154 heat records were broken.

That may sound like a lot—154 record-high temperatures in the span of just one week. But the NOAA website also indicates how many potential records could have been achieved during that time: 18,953. In actuality, less than one percent of these were broken. You can also pull data on daily maximum temperatures for an entire month: I tried that with August 2017, and then again for months of August at 10-year intervals going back to the 1950s. Each time the query returned at least about 130,000 potential records, of which one or two thousand seemed to be getting broken every year. (There was no apparent trend toward more records being broken over time.)

Now let’s say there are 130,000 high-temperature records to be broken every month in the U.S. That’s only half the pool of heat-related records, since the database also lets you search for all-time highest low temperatures. You can also check whether any given highest high or highest low happens to be a record for the entire month in that location, or whether it’s a record when compared across all the weather stations everywhere on that particular day.

Add all of these together and the pool of potential heat records tracked by NOAA appears to number in the millions annually, of which tens of thousands may be broken. Even this vastly underestimates the number of potential records available for media concern. As they’re reported in the news, all-time weather records aren’t limited to just the highest highs or highest lows for a given day in one location. Take, for example, the first heat record mentioned in this column, reported in the Post: The U.S. has just endured the hottest May, June, and July of all time. The existence of that record presupposes many others: What about the hottest April, May and June, or the hottest March, April, and May? What about all the other ways that one might subdivide the calendar?

Geography provides another endless well of flexibility. Remember that the all-time record for the hottest May, June, and July applied only to the lower 48 states. Might a different set of records have been broken if we’d considered Hawaii and Alaska? And what about the records spanning smaller portions of the country, like the Midwest, or the Upper Midwest, or just the state of Minnesota, or just the Twin Cities? And what about the all-time records overseas, describing unprecedented heat in other countries or on other continents?

Even if we did limit ourselves to weather records from a single place measured over a common timescale, it would still be possible to parse out record-breaking heat in a thousand different ways. News reports give separate records, as we’ve seen, for the highest daily high and the highest daily low, but they also tell us when we’ve hit the highest average temperature over several days or several weeks or several months. The Post describes a recent record-breaking streak of days in San Diego with highs of at least 83 degrees. (You’ll find stories touting streaks of daily highs above almost any arbitrary threshold: 90 degrees, 77 degrees, 60 degrees, et cetera.) Records also needn’t focus on the temperature at all: There’s been lots of news in recent weeks about the fact that the U.K. has just endured its driest-ever early summer.

“Record-breaking” summer weather, then, can apply to pretty much any geographical location, over pretty much any span of time. It doesn’t even have to be a record—there’s an endless stream of stories on “near-record heat” in one place or another, or the “fifth-hottest” whatever to happen in wherever, or the fact that it’s been “one of the hottest” yadda-yaddas that yadda-yadda has ever seen. In the most perverse, insane extension of this genre, news outlets sometimes even highlight when a given record isn’t being set.

Loose reports of “record-breaking heat” only serve to puff up muggy weather and make it seem important. (The sham inflations of the wind chill factor do the same for winter months.) So don’t be fooled or flattered by this record-setting hype. Your summer misery is nothing special.

Summary

This article helps people not to confuse weather events with climate.  My disappointment is with the phrase, “Climate Change is Real,” since it is subject to misdirection.  Engber uses that phrase referring to rising average world temperatures, without explaining that such estimates are computer processed reconstructions since the earth has no “average temperature.”  More importantly the undefined “climate change” is a blank slate to which a number of meanings can be attached.

Some take it to mean: It is real that rising CO2 concentrations cause rising global warming.  Yet that is not supported by temperature records.
Others think it means: It is real that using fossil fuels causes global warming.  This too lacks persuasive evidence.
Over the last five decades the increase in fossil fuel consumption is dramatic and monotonic, steadily increasing by 234% from 3.5B to 11.7B oil equivalent tons. Meanwhile the GMT record from Hadcrut shows multiple ups and downs with an accumulated rise of 0.74C over 53 years, 5% of the starting value.

Others know that Global Mean Temperature is a slippery calculation subject to the selection of stations.

Global warming estimates combine results from adjusted records.
Conclusion

The pattern of high and low records discussed above is consistent with natural variability rather than rising CO2 or fossil fuel consumption. Those of us not alarmed about the reported warming understand that “climate change” is something nature does all the time, and that the future is likely to include periods both cooler and warmer than now.

Background Reading:

The Climate Story (Illustrated)

2018 Update: Fossil Fuels ≠ Global Warming

Man Made Warming from Adjusting Data

What is Global Temperature? Is it warming or cooling?

This summer’s heat waves are having an unfortunate side effect. Some scientists who should know better are shouting wild claims as though their heads were exploding.  Paleoclimatologists use terms like “Hothouse” Earth and “Icehouse” Earth referring to our planet’s climate shifts over many eons.  One good old-fashioned hot summer is not a transition, or even an harbinger of an “Hothouse” world.  More importantly, the distribution of temperatures in a warmer world is not the hell on earth depicted by these folks who have lost their bearings.

A powerful post by Clive Best describes how earth’s surface temperatures change by means of changing meridional heat transfers. See Meridional Warming.

The key point for me was seeing how the best geological knowledge proves beyond the shadow of a doubt how the earth’s climate profile shifts over time, as presented in the diagram above.  It comes from esteemed paleoclimatologist Christopher Scotese.  His compete evidence and analysis can be reviewed in his article Some thoughts on Global Climate Change: The Transition from Icehouse to Hothouse (here).

In that essay Scotese shows where we are presently in this cycle between icehouse and hothouse.

As of 2015 earth is showing a GMT of 14.4C, compared to pre-industrial GMT of 13.8C.  According to the best geological evidence from millions of years of earth’s history, that puts us leaving the category “Severe Icehouse,” and nearing “Icehouse.”  So, thankfully we are warming up, albeit very slowly.

Moreover, and this is Clive Best’s point, progress toward a warming world means flattening the profile at the higher latitudes, especially the Arctic.  Equatorial locations remain at 23C throughout the millennia, while the gradient decreases in a warmer world.

A previous related post explained what is wrong with averaging temperature anomalies.  See Temperature Misunderstandings

Conclusion:

We have many, many centuries to go before the earth can warm up to the “Greenhouse” profile, let alone get to “Hothouse.”  Regional and local climates at higher latitudes will see slightly warming temperatures and smaller differences from equatorial climates.  These are facts based on solid geological evidence, not opinions or estimates from computer models.

It is still a very cold world, but we are moving in the right direction.  Stay the course.

Meanwhile, keep firing away Clive.

 

For the last few years, observers have been speculating about when the North Atlantic will start the next phase shift from warm to cold.

An example is this report in May 2015 The Atlantic is entering a cool phase that will change the world’s weather by Gerald McCarthy and Evan Haigh of the RAPID Atlantic monitoring project. Excerpts in italics with my bolds.

This is known as the Atlantic Multidecadal Oscillation (AMO), and the transition between its positive and negative phases can be very rapid. For example, Atlantic temperatures declined by 0.1ºC per decade from the 1940s to the 1970s. By comparison, global surface warming is estimated at 0.5ºC per century – a rate twice as slow.

In many parts of the world, the AMO has been linked with decade-long temperature and rainfall trends. Certainly – and perhaps obviously – the mean temperature of islands downwind of the Atlantic such as Britain and Ireland show almost exactly the same temperature fluctuations as the AMO.

Atlantic oscillations are associated with the frequency of hurricanes and droughts. When the AMO is in the warm phase, there are more hurricanes in the Atlantic and droughts in the US Midwest tend to be more frequent and prolonged. In the Pacific Northwest, a positive AMO leads to more rainfall.

A negative AMO (cooler ocean) is associated with reduced rainfall in the vulnerable Sahel region of Africa. The prolonged negative AMO was associated with the infamous Ethiopian famine in the mid-1980s. In the UK it tends to mean reduced summer rainfall – the mythical “barbeque summer”.Our results show that ocean circulation responds to the first mode of Atlantic atmospheric forcing, the North Atlantic Oscillation, through circulation changes between the subtropical and subpolar gyres – the intergyre region. This a major influence on the wind patterns and the heat transferred between the atmosphere and ocean.

The observations that we do have of the Atlantic overturning circulation over the past ten years show that it is declining. As a result, we expect the AMO is moving to a negative (colder surface waters) phase. This is consistent with observations of temperature in the North Atlantic.

Cold “blobs” in North Atlantic have been reported, but they are usually a winter phenomena. For example in April 2016, the sst anomalies looked like this

But by September, the picture changed to this

And we know from Kaplan AMO dataset, that 2016 summer SSTs were right up there with 1998 and 2010 as the highest recorded.

As the graph above suggests, this body of water is also important for tropical cyclones, since warmer water provides more energy.  But those are annual averages, and I am interested in the summer pulses of warm water into the Arctic. As I have noted in my monthly HadSST3 reports, most summers since 2003 there have been warm pulses in the north atlantic.
The AMO Index is from from Kaplan SST v2, the unaltered and untrended dataset. By definition, the data are monthly average SSTs interpolated to a 5×5 grid over the North Atlantic basically 0 to 70N.  The graph shows warming began after 1992 up to 1998, with a series of matching years since.  Because McCarthy refers to hints of cooling to come in the N. Atlantic, let’s take a closer look at some AMO years in the last 2 decades.

This graph shows monthly AMO temps for some important years. The Peak years were 1998, 2010 and 2016, with the latter emphasized as the most recent. The other years show lesser warming, with 2007 emphasized as the coolest in the last 20 years. Note the red 2018 line is at the bottom of all these tracks.  Most recently June 2018 is 0.4C lower than June 2016.

With all the talk of AMOC slowing down and a phase shift in the North Atlantic, we await SST measurements for July, August and September to confirm if cooling is starting to set in.

Presently sea surface temperatures (SST) are the best available indicator of heat content gained or lost from earth’s climate system.  Enthalpy is the thermodynamic term for total heat content in a system, and humidity differences in air parcels affect enthalpy.  Measuring water temperature directly avoids distorted impressions from air measurements.  In addition, ocean covers 71% of the planet surface and thus dominates surface temperature estimates.  Eventually we will likely have reliable means of recording water temperatures at depth.

Recently, Dr. Ole Humlum reported from his research that air temperatures lag 2-3 months behind changes in SST.  He also observed that changes in CO2 atmospheric concentrations lag behind SST by 11-12 months.  This latter point is addressed in a previous post Who to Blame for Rising CO2?

The June update to HadSST3 will appear later this month, but in the meantime we can look at lower troposphere temperatures (TLT) from UAHv6 which are already posted for June. The temperature record is derived from microwave sounding units (MSU) on board satellites like the one pictured above.

The UAH dataset includes temperature results for air above the oceans, and thus should be most comparable to the SSTs. The graph below shows monthly anomalies for ocean temps since January 2015.

The anomalies are holding close to the same levels as 2015. In June, both the Tropics and SH rose, while NH declined slightly, resulting in a small increase in the Global average of air over oceans. Taking a longer view, we can look at the record since 1995, that year being an ENSO neutral year and thus a reasonable starting point for considering the past two decades.  On that basis we can see the plateau in ocean temps is persisting. Since last October all oceans have cooled, with offsetting bumps up and down.

UAHv6 TLT  Monthly Ocean Anomalies	Average Since 1995	Ocean 6/2018
Global	0.13	0.14
NH	0.16	0.28
SH	0.11	0.03
Tropics	0.12	0.11

As of June 2018, global ocean temps are slightly higher than May and close to the average since 1995.  NH remains higher, but not enough to offset much lower temps in SH and  nearly average Tropics (between 20N and 20S latitudes).  Global ocean air temps are matching the last two March temps, but are the lowest June temps since 2012.  Both NH and SH are the lowest June temps since 2014.

The details of UAH ocean temps are provided below.  The monthly data make for a noisy picture, but seasonal fluxes between January and July are important.

The greater volatility of the Tropics is evident, leading the oceans through three major El Nino events during this period.  Note also the flat period between 7/1999 and 7/2009.  The 2010 El Nino was erased by La Nina in 2011 and 2012.  Then the record shows a fairly steady rise peaking in 2016, with strong support from warmer NH anomalies, before returning to the 22-year average.

Summary

TLTs include mixing above the oceans and probably some influence from nearby more volatile land temps.  They started the recent cooling later than SSTs from HadSST3, but are now showing the same pattern.  It seems obvious that despite the three El Ninos, their warming has not persisted, and without them it would probably have cooled since 1995.  Of course, the future has not yet been written.

 

Presently sea surface temperatures (SST) are the best available indicator of heat content gained or lost from earth’s climate system.  Enthalpy is the thermodynamic term for total heat content in a system, and humidity differences in air parcels affect enthalpy.  Measuring water temperature directly avoids distorted impressions from air measurements.  In addition, ocean covers 71% of the planet surface and thus dominates surface temperature estimates.  Eventually we will likely have reliable means of recording water temperatures at depth.

Recently, Dr. Ole Humlum reported from his research that air temperatures lag 2-3 months behind changes in SST.  He also observed that changes in CO2 atmospheric concentrations lag behind SST by 11-12 months.  This latter point is addressed in a previous post Who to Blame for Rising CO2?

The May update to HadSST3 will appear later this month, but in the meantime we can look at lower troposphere temperatures (TLT) from UAHv6 which are already posted for May. The temperature record is derived from microwave sounding units (MSU) on board satellites like the one pictured above.

The UAH dataset includes temperature results for air above the oceans, and thus should be most comparable to the SSTs. The graph below shows monthly anomalies for ocean temps since January 2015.

The anomalies have reached the same levels as 2015.  Taking a longer view, we can look at the record since 1995, that year being an ENSO neutral year and thus a reasonable starting point for considering the past two decades.  On that basis we can see the plateau in ocean temps is persisting. Since last October all oceans have cooled, with upward bumps in Feb. 2018, now erased.

UAHv6 TLT  Monthly Ocean Anomalies	Average Since 1995	Ocean 5/2018
Global	0.13	0.09
NH	0.16	0.33
SH	0.11	-0.09
Tropics	0.12	0.02

As of May 2018, global ocean temps are slightly lower than April and below the average since 1995.  NH remains higher, but not enough to offset much lower temps in SH and Tropics (between 20N and 20S latitudes).  Global ocean air temps are now the lowest since April 2015, and SH the lowest since May 2013.

The details of UAH ocean temps are provided below.  The monthly data make for a noisy picture, but seasonal fluxes between January and July are important.

The greater volatility of the Tropics is evident, leading the oceans through three major El Nino events during this period.  Note also the flat period between 7/1999 and 7/2009.  The 2010 El Nino was erased by La Nina in 2011 and 2012.  Then the record shows a fairly steady rise peaking in 2016, with strong support from warmer NH anomalies, before returning to the 22-year average.

Summary

TLTs include mixing above the oceans and probably some influence from nearby more volatile land temps.  They started the recent cooling later than SSTs from HadSST3, but are now showing the same pattern.  It seems obvious that despite the three El Ninos, their warming has not persisted, and without them it would probably have cooled since 1995.  Of course, the future has not yet been written.

 

Hidden amid reports of recent warmest months and years based on global averages, there is a significant departure in North America. Those of us living in Canada and USA have noticed a distinct cooling, and our impressions are not wrong.

The image above shows how much lower have been April 2018 temperatures. The table below provides the numbers behind the graphs from NOAA State of the Climate.

CONTINENT	ANOMALY (1910-2000)		TREND (1910-2018)		RANK		RECORDS
	°C	°F	°C	°F	(OUT OF 109 YEARS)		YEAR(S)	°C	°F
North America	-0.97	-1.75	0.11	0.19	Warmest	94ᵗʰ	2010	2.65	4.77
South America	1.34	2.41	0.13	0.24	Warmest	1ˢᵗ	2018	1.34	2.41
Europe	2.82	5.08	0.14	0.25	Warmest	1ˢᵗ	2018	2.82	5.08
Africa	1.23	2.21	0.12	0.22	Warmest	5ᵗʰ	2016	1.72	3.1
Asia	1.66	2.99	0.18	0.32	Warmest	9ᵗʰ	2016	2.4	4.32
Oceania	2.47	4.45	0.14	0.25	Warmest	2ⁿᵈ	2005	2.54	4.57

The table shows how different was the North American experience: 94th out of 109 years.  But when we look at the first four months of the year, the NA is more in line with the rest of the globe.

 

As the image shows, cooling was more widespread during the first third of 2018, particularly in NA, Northern Europe and Asia, as well as a swath of cooler mid ocean latitudes in the Southern Hemisphere.

CONTINENT	ANOMALY (1910-2000)		TREND (1910-2018)		RANK		RECORDS
	°C	°F	°C	°F	(OUT OF 109 YEARS)		YEAR(S)	°C	°F
North America	0.44	0.79	0.16	0.29	Warmest	44ᵗʰ	2016	2.71	4.88
South America	0.94	1.69	0.13	0.24	Warmest	6ᵗʰ	2016	1.39	2.5
Europe	1.35	2.43	0.13	0.24	Warmest	13ᵗʰ	2014	2.46	4.43
Africa	1.08	1.94	0.1	0.18	Warmest	3ʳᵈ	2010	1.62	2.92
Asia	1.57	2.83	0.19	0.34	Warmest	8ᵗʰ	2002	2.72	4.9
Oceania	1.58	2.84	0.12	0.22	Warmest	1ˢᵗ	2018	1.58	2.84

The table confirms that Europe and Asia are cooler in 2018 than recent years in the decade.

Summary

These data show again that temperature indicators of climate are not global but regional, and even local in their manifestations.  At the continental level there are significant differences.  North America is an outlier, but who is to say whether it is an aberration that will join the rest, or whether it is the trend setter signaling a widespread cooler future.

See Also:  Is This Cold the New Normal?

Hidden amid reports of recent warmest months and years based on global averages, there is a significant departure in North America. Those of us living in Canada and USA have noticed a distinct cooling, and our impressions are not wrong.

The image above shows how much lower have been April 2018 temperatures. The table below provides the numbers behind the graphs from NOAA State of the Climate.

CONTINENT	ANOMALY (1910-2000)		TREND (1910-2018)		RANK		RECORDS
	°C	°F	°C	°F	(OUT OF 109 YEARS)		YEAR(S)	°C	°F
North America	-0.97	-1.75	0.11	0.19	Warmest	94ᵗʰ	2010	2.65	4.77
South America	1.34	2.41	0.13	0.24	Warmest	1ˢᵗ	2018	1.34	2.41
Europe	2.82	5.08	0.14	0.25	Warmest	1ˢᵗ	2018	2.82	5.08
Africa	1.23	2.21	0.12	0.22	Warmest	5ᵗʰ	2016	1.72	3.1
Asia	1.66	2.99	0.18	0.32	Warmest	9ᵗʰ	2016	2.4	4.32
Oceania	2.47	4.45	0.14	0.25	Warmest	2ⁿᵈ	2005	2.54	4.57

The table shows how different was the North American experience: 94th out of 109 years.  But when we look at the first four months of the year, the NA is more in line with the rest of the globe.

 

As the image shows, cooling was more widespread during the first third of 2018, particularly in NA, Northern Europe and Asia, as well as a swath of cooler mid ocean latitudes in the Southern Hemisphere.

CONTINENT	ANOMALY (1910-2000)		TREND (1910-2018)		RANK		RECORDS
	°C	°F	°C	°F	(OUT OF 109 YEARS)		YEAR(S)	°C	°F
North America	0.44	0.79	0.16	0.29	Warmest	44ᵗʰ	2016	2.71	4.88
South America	0.94	1.69	0.13	0.24	Warmest	6ᵗʰ	2016	1.39	2.5
Europe	1.35	2.43	0.13	0.24	Warmest	13ᵗʰ	2014	2.46	4.43
Africa	1.08	1.94	0.1	0.18	Warmest	3ʳᵈ	2010	1.62	2.92
Asia	1.57	2.83	0.19	0.34	Warmest	8ᵗʰ	2002	2.72	4.9
Oceania	1.58	2.84	0.12	0.22	Warmest	1ˢᵗ	2018	1.58	2.84

The table confirms that Europe and Asia are cooler in 2018 than recent years in the decade.

Summary

These data show again that temperature indicators of climate are not global but regional, and even local in their manifestations.  At the continental level there are significant differences.  North America is an outlier, but who is to say whether it is an aberration that will join the rest, or whether it is the trend setter signaling a widespread cooler future.