Ocean Temps

[Shared Humanity]

Could this thread be any more off topic?

I don't see how unless I start talking about the impending birth of my 1st grandchild.

This is very annoying and is most noticeable during the freeze season as many of the regulars here who post truly relevant research which I love to read take a hiatus.

[harpy]

Indeed, Archimid; uniformitarianism taken to extremes just doesn't work. Civilisations do collapse, and so do global ecosystems, particularly when you get natural perturbations on the scale of the ones that we're making.

Comparing the '70s and '80s (I assume) pollution problems with climate change isn't really useful. Some problems can be easily solved by a concerted effort, and without harmful side-effects. Toxic sludge going into some of your rivers? Legislate to stop it, and those ecosystems soon recover. Ozone hole? Once you stop the CFC (etc.) emissions, the problem starts to resolve; it might takle a while, but it'll get there.

Climate change is a whole other ball game, because of its global scale, cumulative effects with long lag times, major built-in feedbacks, direct impacts on food propduction and water supplies, and the dependence of our economy of things being as they are until the alternatives catch up. Optimism can be useful, but not when it blinds us to how serious the problems really are, and lulls people into thinking that the problems will magically disappear when someone comes up a neat solution. There are, currently, no neat solutions that will work in time. Without the appearance of new technologies such as carbon scrubbing that can be rolled out globally, almost overnight, I don't see that a viable artificial fix is available.

Excellent post, thank you for your thoughts.

[gerontocrat]

Could this thread be any more off topic?

I don't see how unless I start talking about the impending birth of my 1st grandchild.

This is very annoying and is most noticeable during the freeze season as many of the regulars here who post truly relevant research which I love to read take a hiatus.

Too right, Shared Humanity .

But we can't expect Neven to do all the work on managing the forum.
So, methinks we need to be a bit more firm about this disease infecting the forum.

From now on,I will be naming names - so lay off, Avalonian, Harpy et al. There are threads in "consequences" and "policy and solutions" for this stuff, so use them.

[Shared Humanity]

Could this thread be any more off topic?

I don't see how unless I start talking about the impending birth of my 1st grandchild.

This is very annoying and is most noticeable during the freeze season as many of the regulars here who post truly relevant research which I love to read take a hiatus.

Too right, Shared Humanity .

But we can't expect Neven to do all the work on managing the forum.
So, methinks we need to be a bit more firm about this disease infecting the forum.

From now on,I will be naming names - so lay off, Avalonian, Harpy et al. There are threads in "consequences" and "policy and solutions" for this stuff, so use them.

I will join you in this effort. I hesitate to call people out as I do not want to appear the nag but this is getting ridiculous.

[Bruce Steele]

I think high ocean temperatures and coral bleaching are directly related. Therefore discussing it's potential impacts on humans is fair game.  I wonder if anyone has done any dietary studies on
Isolated human populations highly dependent on reef fish and nearshore invertebrates?
 Getting the larger public to recognize the threats the ocean is being exposed to can be very much improved by knowledge of how those threats impact other humans. The oyster crashes in Oregon and Washington due to ocean acidification being a prime case. I have been a commercial fisherman for over thirty years and we do see things that are missed or ignored by the scientific community and terrestrial humans.
The oyster crashes were spotted by aquaculturists and their causes were also isolated by those same people with the help of experimentation ,monitoring equipment, and university expertise .So if coral bleaching events are impacting indigenous fishermen there should be an attempt to document the human misery caused.
Corals and fish dieoffs in marine reserves or parks are just never going to have the same impact on the larger story that needs to be told. We terrestrial members of civilization are causing the oceans ecosystems to begin to die. Paradise in the South Pacific isn't paradise if the food humans  have survived upon for thousands of years disappears and their islands flood.
 Ocean heating also results in ecosystem shifts that results in the collapse of kelp forests. We are currently having extreme impacts to invertebrates in Northern California largely due to the after affects of the "blob." The red sea urchin fishery there has largely collapsed and abalone stocks are also starving because purple urchin barrens have eaten all the kelp. Purple urchins were never as abundant in Northern California as they currently are with populations reaching an average of 150 per square meter across Calif. Fish and Wildlife monitoring stations. The 2018 recreational fishery for abalone in California has been closed as a result.
Kelp resources in Tazmania are also under severe threat due to increases in ocean temperatures. This has caused a shift in herbivor populations resulting in overgrazed kelp resources. Current ocean temperature anomalies around Tazmania and Southern New Zealand are +3 C.

https://coralreefwatch.noaa.gov/satellite/bleaching5km/animation_current/ssta_animation_30day_pacific_930x580.gif

If you don't like talking about the impacts of high ocean temperatures then my experiences as an ocean observer are useless to you, just ignor me and enjoy your day.
 

[Shared Humanity]

I think high ocean temperatures and coral bleaching are directly related. 

Yes.

Therefore discussing it's potential impacts on humans is fair game.
 

If taken too far no.

This is not relevant.

Also, civilization collapse and starvation are nothing new, but being alive for a few decades in a first world country will lead to the mistaken belief that it can't happen. Climate change is just now getting started.

Nor this.

Indeed, Archimid; uniformitarianism taken to extremes just doesn't work. Civilisations do collapse, and so do global ecosystems, particularly when you get natural perturbations on the scale of the ones that we're making.

Comparing the '70s and '80s (I assume) pollution problems with climate change isn't really useful. Some problems can be easily solved by a concerted effort, and without harmful side-effects. Toxic sludge going into some of your rivers? Legislate to stop it, and those ecosystems soon recover. Ozone hole? Once you stop the CFC (etc.) emissions, the problem starts to resolve; it might takle a while, but it'll get there.

Climate change is a whole other ball game, because of its global scale, cumulative effects with long lag times, major built-in feedbacks, direct impacts on food propduction and water supplies, and the dependence of our economy of things being as they are until the alternatives catch up. Optimism can be useful, but not when it blinds us to how serious the problems really are, and lulls people into thinking that the problems will magically disappear when someone comes up a neat solution. There are, currently, no neat solutions that will work in time. Without the appearance of new technologies such as carbon scrubbing that can be rolled out globally, almost overnight, I don't see that a viable artificial fix is available.

Even quoting this stuff makes me feel bad. I am now the one derailing this thread.

I will now exit.

[Shared Humanity]

And what in the hell does this mean???  uninformitarianism

Just googled it...

u·ni·form·i·tar·i·an·ism
ˌyo͞onəˌfôrməˈterēənizəm
noun GEOLOGY
the theory that changes in the earth's crust during geological history have resulted from the action of continuous and uniform processes.

[Archimid]

My comment was meant to counteract the denier intellectual poison:

Claims of civilization collapse and mass starvation are nothing new. 

That claim is very dangerous because it plays to the very deep confirmation bias that the world can’t end. Ocean temperatures have ended the world before and there is no reason except for “Human exceptionality” to think it won’t do it again.

That said, it is not productive to bring the worst possible consequence of ocean temperatures into every comment. It is more productive to use this thread to share data, information, ideas and questions about more  tangible consequences of ocean temperatures, like changes in the ocean biosphere, ocean chemical composition, ocean currents and other changing systems.

[Avalonian]

I accept that my second post drifted way off topic, in response to what went before. Mea culpa. It won't happen again, and there are indeed other threads where the effects of temperature on fisheries are better discussed. Now can we please stop with all the recriminations? In a case like this, a simple, "Back on topic, please!" would have done the job. That's it from me.

[Neven]

Zeke Hausfather on his paper showing that oceans are warming faster that thought:

[Tom_Mazanec]

National Geographic on toll AGW taking on oceans:
https://www.nationalgeographic.com/environment/2019/06/see-the-drastic-toll-climate-change-is-taking-on-our-oceans/

[Sterks]

Zeke Hausfather on his paper showing that oceans are warming faster that thought:

Another post brought me here, but excellent video anyway. The interviewer is really tendentious in exposing how bad scientists are underestimating the effects of AGW, but the scientist doesn’t really fail in the trap and teaches him what rigor means. Good job!

[b_lumenkraft]

Sterks, this channel is very good in general and definitely deserves more subscriber.

[gerontocrat]

I got around to updating the Ocean Heat Content data from https://www.nodc.noaa.gov/OC5/3M_HEAT_CONTENT/basin_data.html

Graph attached.

Looking at 0-700 metres depth only, the average annual increase in heat content is about 8.5 x 10^21 Joules, nearly 100 times the energy used to melt the average annual loss in Arctic Sea Ice Volume. It is just as well the capacity of the oceans to act as a heat store is so vast. Otherwise we would be frying tonight.

Quote from PIOMAS
To melt the additional 280 km3 of sea ice, the amount we have have been losing on an annual basis based on PIOMAS calculations, it takes roughly 8.6 x 10^19 J or 86% of U.S. energy consumption.

[vox_mundi]

New Study: Ocean Temperature 'Surprises' Becoming More Common
https://phys.org/news/2019-08-ocean-temperature-common.html

August 5, 2019—A new study published this week shows how marine ecosystems around the world are experiencing unusually high ocean temperatures more frequently than researchers previously expected. These warming events, including marine heatwaves, are disrupting marine ecosystems and the people who depend on them.

Dr. Pershing and his colleagues examined 65 large marine ecosystems from 1854-2018 to identify the frequency of surprising ocean temperatures, which they defined as an annual mean temperature that is two standard deviations above the mean of the previous three decades.

The researchers identified these "surprises" all over the world, including the Arctic, North Atlantic, eastern Pacific, and off of Australia. Moreover, these warming events occurred at nearly double the rate the scientists expected.

"Across the 65 ecosystems we examined, we expected about six or seven of them would experience these 'surprises' each year," explains Pershing. "Instead, we've seen an average of 12 ecosystems experiencing these warming events each year over the past seven years, including a high of 23 'surprises' in 2016."

... "We are entering a world where history is an unreliable guide for decision making," ... "In a rapidly changing world, betting that trends will continue is a much better strategy."

Frequency and spatial pattern of surprising ocean temperatures. (A) The difference between the observed and expected number of surprises in 20-y windows plotted by regions (SI Appendix, Fig. S1). (B) The observed minus expected surprises between 1997 and 2018 for the LMEs and the open ocean (LME names defined in SI Appendix, Table S1). (C) Observed and expected surprises modeled as a function of the change in trend and in variance (R2 = 0.35, P < 0.01). (D) The mean temperature trend and variability of the LMEs in 2018 (black star with 75% ellipse) and projected for 2030, 2060, and 2090 (blue, purple, and red squares, respectively). Individual LMEs in 2018 are shown (circles). Note that the 2 LMEs with slightly negative trends, Humboldt Current (r = −0.006, ɣ = 0.38) and Patagonian Shelf (r = −0.004, ɣ = 0.28), are not shown.

Open Access: Andrew J. Pershing el al., "Challenges to natural and human communities from surprising ocean temperatures," PNAS (2019).

[vox_mundi]

Microfossils Map Extreme Global Warming and Environmental Change
https://phys.org/news/2019-08-microfossils-extreme-global-environmental.html

Studies of marine microfossils, known as conodonts, have allowed a team of researchers from Australia and China to map extreme global warming which coincided with the most severe mass extinction on Earth approximately 252 million years ago at the end of the Permian period.

... "Conodont microfossils are the only known hard parts of an extinct ancient group of marine primitive fish-like vertebrates that swam in the Earth's oceans from the Late Cambrian to the end of the Triassic about 500 to 200 million years ago.

By researching size variations in conodont populations, the team were able to successfully map geologically rapid changes in global temperatures which continued in the aftermath of the mass extinction in the early Triassic.

... "Ancient sea-surface temperatures, at the end-Permian mass extinction level and Permian-Triassic boundary, where lethally hot and in excess of 37^oC,"

- Prof. Metcalfe

Their research findings further revealed that dangerous variations in global sea-surface temperatures continued for the subsequent five million years in the Early Triassic period.



Kui Wu et al. Recurrent biotic rebounds during the Early Triassic: biostratigraphy and temporal size variation of conodonts from the Nanpanjiang Basin, South China, Journal of the Geological Society (2019).

-------------------------

Sous-vide for 5 million years!

[Tom_Mazanec]

New ocean-centric approach for detecting climate change
http://www.digitaljournal.com/news/environment/new-ocean-centric-approach-for-detecting-climate-change/article/557003

The research from Princeton University is focused on when humanity can expect to detect further changes to the oceans as the result of climate change. The new study has found that some changes are already underway, whereas as other changes will take a little longer to appear, provided that global warming continues at its current trajectory.
The scientists, who were sponsored by NASA, examined various physical and chemical changes impacting upon the ocean linked with increases to atmospheric carbon dioxide as the result of human activities. The research indicates that over the past thirty years a number of changes have already taken place, and these changes are set to continue.

Read more: http://www.digitaljournal.com/news/environment/new-ocean-centric-approach-for-detecting-climate-change/article/557003#ixzz5yO2xEr75

INTERVIEW-Ocean treaty needed to tackle 'deep trouble', says UN envoy
http://news.trust.org/item/20190831063635-oygwk/

The world's seas are increasingly threatened by global warming, acidification and pollution, making it crucial to agree on a global treaty to protect them, the U.N. oceans envoy said.

Peter Thomson warned in an interview with the Thomson Reuters Foundation that the oceans were "in deep trouble".

"It is worse than we think and there are no easy solutions," he said at World Water Week in Stockholm this week, as the latest round of talks on a treaty wound up in New York.

[Tom_Mazanec]

Scientists monitoring new marine heat wave off B.C. coast similar to 'the Blob'
https://www.cbc.ca/news/canada/british-columbia/marine-heatwave-2019-the-blob-1.5271870

A new marine heat wave spreading across a portion of the Pacific Ocean off the coast of British Columbia has so far grown into one of the largest of its kind in the last four decades, officials say, second only to the infamous "blob" that disrupted marine life five years ago.

The swath of unusually warm water stretches roughly from Alaska down to California, according to the National Oceanic and Atmospheric Administration (NOAA) in the United States. The marine phenomenon began in the Gulf of Alaska sometime around June 15 and ballooned over the summer.

[Pmt111500]

Scientists monitoring new marine heat wave off B.C. coast similar to 'the Blob'
https://www.cbc.ca/news/canada/british-columbia/marine-heatwave-2019-the-blob-1.5271870

A new marine heat wave spreading across a portion of the Pacific Ocean off the coast of British Columbia has so far grown into one of the largest of its kind in the last four decades, officials say, second only to the infamous "blob" that disrupted marine life five years ago.

The swath of unusually warm water stretches roughly from Alaska down to California, according to the National Oceanic and Atmospheric Administration (NOAA) in the United States. The marine phenomenon began in the Gulf of Alaska sometime around June 15 and ballooned over the summer.

As expected, this might well become a regular feature for North American western seaboard. The tropical heat pushed by Kuroshio now lacks the cooling effect of Bering Sea and that heat is trapped to the North Pacific for La Nina-like conditions in tropics. Guessing this area will continue to gather heat until the next proper El Nino, unless it finds it's way to Arctic Ocean by some random (but long-lived) weather fluctuation.

That sort of atmospheric driver would probably cause an instant BOE. We're looking at a live (weather) bomb, but we don't know where the trigger to set it off is.

Some talk 2016
https://forum.arctic-sea-ice.net/index.php/topic,1454.msg90124.html#msg90124

[Pmt111500]

Jai Mitchell back when the Blob was not a blob yet: https://forum.arctic-sea-ice.net/index.php/topic,784.msg28039.html#msg28039

[TerryM]

<snipped>
As expected, this might well become a regular feature for North American western seaboard. The tropical heat pushed by Kuroshio now lacks the cooling effect of Bering Sea and that heat is trapped to the North Pacific for La Nina-like conditions in tropics. Guessing this area will continue to gather heat until the next proper El Nino, unless it finds it's way to Arctic Ocean by some random (but long-lived) weather fluctuation.

That sort of atmospheric driver would probably cause an instant BOE. We're looking at a live (weather) bomb, but we don't know where the trigger to set it off is.

Some talk 2016
https://forum.arctic-sea-ice.net/index.php/topic,1454.msg90124.html#msg90124

I'm in total agreement.
The "trigger" as I see it is the continuing Sea Level Rise. The Bering Straits sill is only ~50m in depth. A 50cm increase in sea level is then a 1% increase in sill depth.
Since the shores of the strait are not vertical, a 1% difference in sill depth is not a 1% increase in water volume over the sill but a much greater volume (probably >500% for each 1% of additional depth).


This additional Warm Pacific Water will enter with the Pacific Coastal Current because of the Coriolis effect and will follow down the Northern Coast of Alaska melting what had once been the very old and thick ice once found in the Chukchi and Beaufort Seas.
The flow of Warm Atlantic Water entering from the Barentsz Sea and flowing along the Russian coast is also enhanced by the (effective) lowering of Bering Sill & this effects the Arctic Sea Ice on that side of the ocean.


This process is occuring now, and will only speed up as ocean levels rise. While the melting of all of this sea ice has no effect on SLR, the resultant warm weather melts northern glaciers that do have an effect.
A peek at today's ASI illustrates the above.
Terry

[Bruce Steele]

Re. The 2014 blob had lots of biological impacts here in the Calif Current Ecosystem. I have talked about the disease issues we have been seeing in various nearshore reef fauna and flora and a lot of trouble is still with us five years later. Another blob of similar strength would be a another disaster but heat intolerance and the diseases that seem to follow the anomalous ocean heat waves are only the beginning , I fear.

https://www.sciencemag.org/news/2019/01/ocean-heat-waves-pacific-s-deadly-blob-could-become-new-normal

[Bruce Steele]

Modeling shows anchovy populations may crash in Southern Calif. offshore waters. We have long term biological data sets and monitoring efforts stretching back seventy years, called CAL COFI . Anchovy and sardine population and egg counts are sampled by ocean cruises on an annual basis. As the ocean heats it also stratifies. The bacterial remineralization of primary production and the heating results in decreased oxygen levels. Those low levels of oxygen are already affecting anchovy populations by pushing the anchovy into shallower coastal waters where oxygen levels are higher. The habitat range is shrinking. Any long term restriction in the biomass of an important forage component of the ecosystem will reverberate up through higher trophic levels.
 Curtis Deutsch has a presentation on the hypoxia issues that are affecting the Anchovy and it's future in Southern Calif. on this you tube presentation

https://m.youtube.com/watch?feature=youtu.be&v=VOlZUorIRK0

Yes it will take an hour of listening to get through the first two presentations but considering that there have only been 17 views so far you might get info most people never see. I am always kinda careful with work that may still be embargoed so sorry if I can't upload more.

[Pmt111500]

Icelandic waters are occasionally too hot for the capelin, an important prey species for the cod. Capelins move north to Greenland coast and cod numbers plummet. So it's not just you Pacific north.

https://grapevine.is/news/2019/08/27/capelin-shortage-threatens-cod-population/

[Bruce Steele]

I have been missing the PDO index monthly updates for a year and decided to ask NOAA why they are missing? I got and answer and was directed to another site that is maintaining the PDO index.

https://oceanview.pfeg.noaa.gov/erddap/tabledap/cciea_OC_PDO.graph

The 2019 numbers are in a graph form but they show that the PDO numbers have increased in the last year.

Here are the numbers up through Jan. 2018 in the monthly index I was used to visiting. I am going to recommend NOAA maintain and update the index in it's original form because I like long continuous  datasets. But I am happy to see the data in being maintained and accessible .

http://research.jisao.washington.edu/pdo/PDO.latest.txt

[blumenkraft]

Global Warming of the Seas

Link >> https://www.reddit.com/r/dataisbeautiful/comments/f388j6/oc_global_warming_of_the_seas/

[kassy]

Facinating. Turning pretty pink-reddish in the end even going from 1981-2010 baseline.

[kassy]

Warmest Oceans on Record Could Set Off a Year of Extreme Weather

...

Parts of the Atlantic, Pacific and Indian Oceans all hit the record books for warmth last month, according to the U.S. National Centers for Environmental Information. The high temperatures could offer clues on the ferocity of the Atlantic hurricane season, the eruption of wildfires from the Amazon region to Australia, and whether the record heat and severe thunderstorms raking the southern U.S. will continue.

In the Gulf of Mexico, where offshore drilling accounts for about 17% of U.S. oil output, water temperatures were 76.3 degrees Fahrenheit (24.6 Celsius), 1.7 degrees above the long-term average, said Phil Klotzbach at Colorado State University.

....

“The entire tropical ocean is above average,” said Michelle L’Heureux, a forecaster at the U.S. Climate Prediction Center. “And there is a global warming component to that. It is really amazing when you look at all the tropical oceans and see how warm they are.”

...

Overall, the five warmest years in the world’s seas, as measured by modern instruments, have occurred over just the last half-dozen or so years. It’s “definitely climate-change related,” said Jennifer Francis, a senior scientist at the Woods Hole Research Center in Massachusetts. “Oceans are absorbing about 90% of the heat trapped by extra greenhouse gases,”

Worldwide, sea temperatures were 1.49 degrees Fahrenheit above average in March. That’s the second highest level recorded since 1880 for the month of March, according to U.S. data. In 2016, temperatures were 1.55 degrees above average.

...

The searing global temperatures this year can also be traced back to intense climate systems around the Arctic that bottled up much of that region’s cold, preventing it from spilling south into temperate regions. Combined with global warming, this was a one-two punch for sea temperatures that’s brought them to historic highs.

https://www.bnnbloomberg.ca/warmest-oceans-on-record-could-set-off-a-year-of-extreme-weather-1.1423355

[kassy]

Ocean: How the blob came back

Weak winds in the Pacific drove record-breaking 2019 summertime marine heat wave

Summary:
Weakened wind patterns likely spurred the wave of extreme ocean heat that swept the North Pacific last summer, according to new research.

...

"Most large marine heat waves have historically occurred in the winter," said Dillon Amaya, a postdoctoral Visiting Fellow at CIRES and lead author on the new study out this week in Nature Communications. "This was the first summertime marine heat wave in the last five years -- and it's also the hottest: a record high ocean temperature for the last 40 years."

And that wasn't the only record: 2019 also saw the weakest North Pacific atmospheric circulation patterns in at least the last 40 years. "This was truly a 99th-percentile type of event, with impacts like slow winds felt around the North Pacific," Amaya said.

To search for physical processes that might have influenced the formation of Blob 2.0 in summertime, the team paired real world sea surface temperature data with an atmospheric model, and tested the impacts of various possible drivers.

The most likely culprit: weaker winds. In short, when circulation patterns weaken, so does the wind. With less wind blowing over the ocean's surface, there's less evaporation and less cooling: The process is similar to wind cooling off human skin by evaporating sweat. In 2019, it was as if the ocean was stuck outside on a hot summer day with no wind to cool it down.

A thinning of the ocean's mixed layer, the depth where surface ocean properties are evenly distributed, also fueled the Blob 2.0, the researchers found. The thinner the mixed layer, the faster it warms from incoming sunlight and weakened winds. And the impacts can keep accumulating in a vicious cycle: the lower atmosphere above the ocean responds to warmer water by burning off low clouds, which leaves the ocean more exposed to sunlight, which warms the ocean more, and burns off even more clouds.

https://www.sciencedaily.com/releases/2020/04/200421150232.htm

OA:
https://www.nature.com/articles/s41467-020-15820-w

[Tigertown]

Can these two ocean temperature threads be combined maybe?

[kassy]

Since they seem to co-exist happily since 2018 they can stay that way.

[vox_mundi]

Fidelity of El Nino Simulation Matters for Predicting Future Climate
https://phys.org/news/2020-08-fidelity-el-nino-simulation-future.html

A new study led by University of Hawai'i at Mānoa researchers, published in the journal Nature Communications this week, revealed that correctly simulating ocean current variations hundreds of feet below the ocean surface—the so-called Pacific Equatorial Undercurrent—during El Niño events is key in reducing the uncertainty of predictions of future warming in the eastern tropical Pacific.

... "Only one-third of all climate models can reproduce the strength of the subsurface current and associated ocean temperature variations realistically."

"Remarkably, in these models we see a very close relationship between the change of future El Niño and La Niña intensity and the projected tropical warming pattern due to greenhouse warming," noted Stuecker. In contrast, the models that simulate a future decrease of El Niño and La Niña intensity show less greenhouse gas-induced warming in the eastern part of the basin. The presence of that relationship indicates that those models are capturing a mechanism known to impact climate—signifying that those models are more reliable. This relationship totally disappears in the two-thirds of climate models that cannot simulate the subsurface ocean current variations correctly.



Michiya Hayashi, et.al., Dynamics for El Niño-La Niña asymmetry constrain equatorial-Pacific warming pattern, Nature Communications, 2020
https://www.nature.com/articles/s41467-020-17983-y

[glennbuck]

After analyzing data from the 1950s through 2019, an international team of scientists determined that the average temperature of the world's oceans in 2019 was 0.075 degrees Celsius (0.135 degrees Fahrenheit) higher than the 1981–2010 average.

That might not seem like a significant amount of warming, but given the massive volume of the oceans, an increase even that small would require a staggering influx of heat - 228 sextillion Joules' worth, according to the scientists' study, which was published in the journal Advances in Atmospheric Sciences on Monday.

That's a hard number to contextualize, so one of the scientists behind the study did the math to put it into an explosive frame of reference - by comparing it to the amount of energy released by the atomic bomb the United States military dropped on Hiroshima, Japan, in 1945.

"The Hiroshima atom-bomb exploded with an energy of about 63,000,000,000,000 Joules," author Lijing Cheng from the Chinese Academy of Sciences said in a press release.

"The amount of heat we have put in the world's oceans in the past 25 years equals to 3.6 billion Hiroshima atom-bomb explosions."

That averages out to four Hiroshima bombs' worth of energy entering the oceans every second for the past 25 years. But even more troubling, the rate isn't holding steady at that alarming figure - it's increasing.

https://www.sciencealert.com/the-ocean-is-warming-at-a-rate-of-5-atom-bombs-per-second-says-study?fbclid=IwAR1pgm2P0fCtJo40h4vnbjrVoX5hL2ekFktSPmUFssVms9oVn26ORbolKQU

https://link.springer.com/content/pdf/10.1007/s00376-020-9283-7.pdf

[vox_mundi]

Marine Heatwaves are Human-Made
https://phys.org/news/2020-09-marine-heatwaves-human-made.html



Heatwaves in the world's oceans have become over 20 times more frequent due to human influence. This is what researchers from the Oeschger Center for Climate Research at the University of Bern are now able to prove. Marine heatwaves destroy ecosystems and damage fisheries.

In a study recently published in Science, Charlotte Laufkötter, Jakob Zscheischler and Thomas Frölicher concluded that the probability of such events has increased massively as a result of global warming. The analysis has shown that in the past 40 years, marine heatwaves have become considerably longer and more pronounced in all of the world's oceans. "The recent heatwaves have had a serious impact on marine ecosystems, which need a long time to recover afterwards—if they ever fully recover," explains Charlotte Laufkötter.

In its investigations, the Bern team studied satellite measurements of the sea surface temperature between 1981 and 2017. It was found that in the first decade of the study period, 27 major heatwaves occurred which lasted 32 days on average. They reached maximum temperatures of 4.8 degrees Celsius above the long-term average temperature.

In the most recent decade to be analyzed, however, 172 major events occurred, lasting an average of 48 days and reaching peaks of 5.5 degrees above the long-term average temperature. The temperatures in the sea usually fluctuate only slightly. Week-long deviations of 5.5 degrees over an area of 1.5 million square kilometers—an area 35 times the size of Switzerland—present an extraordinary change to the living conditions of marine organisms.

For the seven marine heatwaves with the greatest impact, researchers at the University of Bern carried out what is referred to as attribution studies. Statistical analyses and climate simulations are used to assess the extent to which anthropogenic climate change is responsible for the occurrence of individual extremes in the weather conditions or the climate. Attribution studies typically demonstrate how the frequency of the extremes has changed through human influence.



Laufkötter et al., High-impact marine heatwaves attributable to human-induced global warming, Science (2020)
https://science.sciencemag.org/content/369/6511/1621

[vox_mundi]

Major Wind-Driven Ocean Currents Are Shifting Toward the Poles
https://phys.org/news/2020-09-major-wind-driven-ocean-currents-shifting.html


"Satellite observational sea surface temperature anomaly during the last five years (2015-2019), reference to the first five years (1982-1986)". Credit: Alfred-Wegener-Institut/Gerrit Lohmann

The severe droughts in the USA and Australia are the first sign that the tropics, and their warm temperatures, are apparently expanding in the wake of climate change. But until now, scientists have been unable to conclusively explain the reasons for this, because they were mostly focusing on atmospheric processes. Now, experts at the AWI have solved the puzzle: the alarming expansion of the tropics is not caused by processes in the atmosphere, but quite simply by warming subtropical ocean.

To date, experts assumed that processes in the atmosphere played a major role—for instance a change in the ozone concentration or the aerosols. It was also thought possible that the natural climate fluctuations that occur every few decades were responsible for the expansion of the tropics. For many years researchers had been looking in the wrong place, so to speak.

"Our simulations show that an enhanced warming over the subtropical ocean in both the Northern and Southern Hemispheres are the main drivers," says Hu Yang, the study's lead author. These subtropical warming patterns are generated by the dynamic of subtropical ocean gyres, measuring several hundreds of kilometers in diameter, which rotate slowly. These currents are especially well-known in the Pacific, because the majority of floating marine litter is concentrated in them. "Because the currents in the region bring together the surface warming water masses particularly intensely, it's easier for the subtropical ocean surface to accumulate warmth than in other regions—and the same applies to plastic," says Lohmann. As a result of this warming of the subtropical ocean, the tropical warm ocean regions are expanding. According to his calculations, this phenomenon is the catalyst for the tropics expanding to the north and south. "Previous researchers had been taking an overly complicated approach to the problem, and assumed it was due to complex changes in the atmosphere. In reality, it's due to a relatively simple mechanism involving ocean currents."

What led the experts to explore this avenue: data on ocean gyres that they happened to come across five years ago—data on ocean temperatures and satellite-based data, freely available on databases. Both sources indicated that the gyres were becoming warmer and more powerful. "That's what led us to believe that they might be a decisive factor in the expansion of the tropics," explains Hu Yang.

The AWI experts were right: their findings perfectly correspond to actual observations and the latest field data on tropical expansion. Just like in reality, their climate model shows that the tropics are now stretching farther to the north and south alike. In the Southern Hemisphere, the effect is even more pronounced, because the ocean takes up more of the overall area there than in the Northern Hemisphere.



Hu Yang et al, Tropical Expansion Driven by Poleward Advancing Midlatitude Meridional Temperature Gradients, Journal of Geophysical Research: Atmospheres (2020)
https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2020JD033158

[gerontocrat]

Major Wind-Driven Ocean Currents Are Shifting Toward the Poles
https://phys.org/news/2020-09-major-wind-driven-ocean-currents-shifting.html
Just like in reality, their climate model shows that the tropics are now stretching farther to the north and south alike. In the Southern Hemisphere, the effect is even more pronounced, because the ocean takes up more of the overall area there than in the Northern Hemisphere.

That's my Saturday morning taken up.

On the one hand we have (as discussed by AbruptSLR) increased surface melt and calving of the Antarctic Ice Sheet that forms a surface layer of cold less dense freshwater to expand northwards from the Antarctic Continent. i.e. surface cold spreads north.

I posted some time ago on The Antarctic Sea Ice thread a speculation that belongs to me that on the other hand we have warmth from AGW heading from the tropics south. This research article says not just atmospheric heat but ocean heat as well.

So the question is - what happens when they strengthen and meet as is happening now and will continue to strengthen in the future?

[Niall Dollard]

Major Wind-Driven Ocean Currents Are Shifting Toward the Poles
https://phys.org/news/2020-09-major-wind-driven-ocean-currents-shifting.html

Thanks for the link Vox Mundi. Hope you dont mind just reposting the image to include the caption

"Satellite observational sea surface temperature anomaly during the last five years (2015-2019), reference to the first five years (1982-1986)". Credit: Alfred-Wegener-Institut/Gerrit Lohmann

[vox_mundi]

Thanks Niall Dollard

I edited the original.

[Hefaistos]

That's my Saturday morning taken up.

On the one hand we have (as discussed by AbruptSLR) increased surface melt and calving of the Antarctic Ice Sheet that forms a surface layer of cold less dense freshwater to expand northwards from the Antarctic Continent. i.e. surface cold spreads north.

I posted some time ago on The Antarctic Sea Ice thread a speculation that belongs to me that on the other hand we have warmth from AGW heading from the tropics south. This research article says not just atmospheric heat but ocean heat as well.

So the question is - what happens when they strengthen and meet as is happening now and will continue to strengthen in the future?

ASLR also claims that the A(MOC) is slowing.

This research shows that ocean gyres are strengthening and moving polewards. Seems to me to be another piece of evidence that the A(MOC) is indeed strengthening and transporting more heat polewards. As expected in a warming world.

In any case, the ocean MOC transport is a slow process, it can take 100's of years before the increased energy arrives at the Antarctica. Many Saturday mornings to go...

[S.Pansa]

That's my Saturday morning taken up.

On the one hand we have (as discussed by AbruptSLR) increased surface melt and calving of the Antarctic Ice Sheet that forms a surface layer of cold less dense freshwater to expand northwards from the Antarctic Continent. i.e. surface cold spreads north.

I posted some time ago on The Antarctic Sea Ice thread a speculation that belongs to me that on the other hand we have warmth from AGW heading from the tropics south. This research article says not just atmospheric heat but ocean heat as well.

So the question is - what happens when they strengthen and meet as is happening now and will continue to strengthen in the future?

<snip>...  ASLR also claims that the A(MOC) is slowing. ... <snip>

Not only ASLR is claiming that. Most recent climate assessments do as well, as this nice summary on RealClimate suggests.

[/quote]...that the A(MOC) is indeed strengthening and transporting more heat polewards. As expected in a warming world. [/quote]

The science seems not settled on this yet but again the above mentioned Assessments claim otherwise: at least if you look at longer time periods (on the "controversy" see for example the comment from Mike Mann, linked by Susan Anderson on the recent RC article).

But more importantly: You may be expecting that the AMOC will strengthen in a warmer world. Climate scientists do not though .
The 4th US National Climate Assessment for instance has this to say:

Though observational data have been insuffi­cient to determine if a long-term slowdown in the AMOC began during the 20th century, one recent study quantifies a 15% weakening since the mid-20th century and another, a weakening over the last 150 years. Over the next few decades, however, it is very likely that the AMOC will weaken. (my bold)

[kassy]

This research shows that ocean gyres are strengthening and moving polewards. Seems to me to be another piece of evidence that the A(MOC) is indeed strengthening and transporting more heat polewards. As expected in a warming world.

But the gyres are not directly related. They are a surface phenomenon while the AMOC has this deep flow.

[gerontocrat]

In any case, the ocean MOC transport is a slow process, it can take 100's of years before the increased energy arrives at the Antarctica. Many Saturday mornings to go...

Altough the subtropical convergence zones (SCZ) of the Southern Hemisphere seem to be between  30 & 40 degrees south, the effects in places seem to reach as far south as 55 degrees South and even beyond.

Winter Antarctic Sea ice extends this year mostly to between 60 and 55 degrees South.

My guess is that already there is an interaction - e.g. an increased temperature gradient from the warm tropical waters to the cold southern ocean waters. So maybe something is already happening on this saturday morning?

[interstitial]

complete mixing of the ocean is slow but the currents are much faster

[Hefaistos]

...that the A(MOC) is indeed strengthening and transporting more heat polewards. As expected in a warming world.

The science seems not settled on this yet but again the above mentioned Assessments claim otherwise: at least if you look at longer time periods (on the "controversy" see for example the comment from Mike Mann, linked by Susan Anderson on the recent RC article).

But more importantly: You may be expecting that the AMOC will strengthen in a warmer world. Climate scientists do not though .
The 4th US National Climate Assessment for instance has this to say:

Though observational data have been insuffi­cient to determine if a long-term slowdown in the AMOC began during the 20th century, one recent study quantifies a 15% weakening since the mid-20th century and another, a weakening over the last 150 years. Over the next few decades, however, it is very likely that the AMOC will weaken. (my bold)

S.Pansa, the bolded statement at the end of your quote is exactly where I disagree. The AMOC might well have weakened in a longer historic perspective, but there is quite a few reports that indicate that it's currently strengthening. For completeness, I provide a list of papers here.

1. "On freshwater fluxes and the Atlantic meridional overturning circulation", by Cael and Jansen, january 2020
From the Abstract: "Our results robustly suggest that for the equilibrium state of the modern ocean, freshwater fluxes strengthen the AMOC..."
https://aslopubs.onlinelibrary.wiley.com/doi/full/10.1002/lol2.10125

2. "Indian Ocean warming can strengthen the Atlantic meridional overturning circulation. Nature Climate Change, in press (September 2019)., Hu, S., and Fedorov, A.V.
From Abstract: "Here, we describe how a salient feature of anthropogenic climate change – enhanced warming of the tropical Indian ocean (TIO) – can strengthen the Atlantic meridional overturning circulation (AMOC) by modulating salinity distribution in the Atlantic (Hu and Fedorov 2019). "
https://agu.confex.com/agu/osm20/meetingapp.cgi/Paper/649185

The big issue is, where are those freshwater pulses going to come from that might trigger those tipping points? I don't see enough of Greenland glacier melt-off for that during the coming decades. And the volume of freshwater in the lens on top of the Arctic won't be enough, supposedly.
Furthermore, the theory isn't even settled, as this quote from paper 1. shows: "Our results robustly suggest that for the equilibrium state of the modern ocean, freshwater fluxes strengthen the AMOC, in the sense that an amplification of the existing freshwater flux‐forcing pattern leads to a strengthening of the AMOC and vice versa. A simple physical argument explains these results: the North Atlantic is anomalously salty at depth and increased freshwater fluxes act to amplify that salinity pattern, resulting in enhanced AMOC transport."

Thus, the question remains completely unsettled, both empirically and theoretically.

3. "Surface predictor of overturning circulation and heat content change in the subpolar North Atlantic" by Desbruyères et al.
https://os.copernicus.org/articles/15/809/2019/
2019, Ocean Sci., 15, 809–817
They clearly demonstrate that the AMOC is currently strengthening, and they even give a bold forecast for the coming years:

"An easily observed surface quantity – the rate of warm to cold transformation of water masses at high latitudes – is found to lead the observed AMOC at 45∘ N by 5–6 years and to drive its 1993–2010 decline and its ongoing recovery, with suggestive prediction of extreme intensities for the early 2020s."

AMOC is forecasted to have "extreme intensities" in the coming years, as the AMOC is 'downstream' with a lag of 5 to 6 years from the already intensified warm to cold transformation of water masses at high latitudes.

4. "Pending recovery in the strength of the meridional overturning circulation at 26° N"
https://www.researchgate.net/publication/338658885_Pending_recovery_in_the_strength_of_the_meridional_overturning_circulation_at_26_N
by Moat, Smeed et al, Jan 2020
This is by the guys who actually 'run' the RAPID array.

5. "The North Atlantic Ocean Is in a State of Reduced Overturning", Jan 2019
by Smeed et al
https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1002/2017GL076350
From the conclusions:
"Our results show that the previously reported decline of the AMOC (Smeed et al., 2014) has been arrested, but the length of the observational record of the AMOC is still short relative to the time scales of importantdecadal variations that exist in the Atlantic. Understanding is therefore constantly evolving. What we identify as a changed state of the AMOC in this study may well prove to be part of a decadal oscillation superposed on a multidecadal cycle"

What they say in the last sentence is that all this is probably due to natural variations. Which is to be expected, as the AMOC, as well as its Pacific Ocean counterparts, eg. the PDO, have overturning times that are multi-decadal.

[vox_mundi]

Scientists Behind New Study Warn Increasingly Stable Oceans Are 'Very Bad News'
https://www.ecowatch.com/stable-oceans-climate-crisis-2647855196.html
https://www.theguardian.com/environment/2020/sep/28/how-our-warmer-oceans-are-contributing-to-climate-breakdown

In a rare calm moment during a historically active Atlantic hurricane season, an international team of climate scientists on Monday published a new study in the journal Nature Climate Change showing that human-caused global heating is making the world's oceans more "stable"—which, as co-author Michael Mann explained, is "very bad news."

The team—led by Guancheng Li of the Institute of Atmospheric Physics in China—specifically found that stratification globally increased by a "substantial" 5.3% from 1960 to 2018, mostly in the upper 650 feet or so of the world oceans. "This seemingly technical finding has profound and troubling implications," Mann noted.

"The more stable the upper ocean, the less vertical mixing that takes place. This mixing is a primary means by which the ocean buries warming surface waters. So the surface warms up even faster. It's what we call a 'positive feedback'—a vicious cycle," he wrote. "That's bad for a number of reasons."

Noting the ongoing storm season and previous warnings from scientists—including him—that the increasingly devastating recent hurricanes "have fed off warmer surface waters," Mann explained that "a more stably stratified ocean potentially favors more intense, destructive hurricanes." Warmer waters also "absorb less atmospheric carbon dioxide" and "hold less dissolved oxygen."

In other words, the new study indicates that "humans have made the oceans more stable, and the result will be more extreme weather and the acceleration of climate change," as study co-author John Abraham wrote Monday for The Guardian. Like Mann, he detailed the research team's findings about the stratification of the oceans, and the implications. ...

Guancheng Li, et.al., Increasing ocean stratification over the past half-century Nature Climate Change (2020)
https://www.nature.com/articles/s41558-020-00918-2