Archive for the ‘Ocean dynamics’ Category

Icebergs in the North Atlantic [image credit:
maritime-executive.com]


Perhaps, but there’s plenty of ‘suggesting’ that something might possibly occur here. Plus of course the usual remarks about supposed human involvement in Earth’s climate. ‘An increased export of Arctic sea-ice into the subpolar North Atlantic’ is proposed as a driver of destabilisation (see study).
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Scientists have used centuries-old clam shells to see how the North Atlantic climate system reached a “tipping point” before the Little Ice Age, says Phys.org.

The Little Ice Age —a period of regional cooling, especially in the North Atlantic—lasted several centuries, ending in about 1850.

A long-standing theory suggests initial cooling in this period was sustained by “sea-ice to ocean feedbacks”—sea ice expanded and this slowed ocean currents which in turn reduced the flow of warm water from the south.

The new study, by the University of Exeter, used the shells of quahog clams—which can live for several hundred years—to understand how the ocean has evolved and responded to external changes over recent centuries.

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It could still be active into next spring, according to some forecasters. Unusual by its own historical (back to 1950) standards.
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La Niña continues! It’s likely that the La Niña three-peat will happen: the chance that the current La Niña will last through early winter is over 70%, says NOAA’s ENSO blog.

If it happens, this will be only the third time with three La Niña winters in a row in our 73-year record.

ENSO (El Niño/Southern Oscillation, the whole La Niña and El Niño system) has the greatest influence on weather and climate during the Northern Hemisphere cold season, so forecasters pay especially close attention when it looks like ENSO will be active in the winter.

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CO2 is not pollution


The researchers are not going overboard with positivity, but seem clear that the Earth’s carbon cycle is still working much as expected. Unsurprisingly perhaps, they theorise problems might occur by 2100 if some presently unknown limit is approached, but say ‘the Twilight Zone region of the ocean’ needs more research. In short, so far so good.
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The amount of carbon stored by microscopic plankton will increase in the coming century, predict researchers at the University of Bristol and the National Oceanography Centre (NOC).

Using the latest IPCC models (Intergovernmental Panel on Climate Change), the team expects the “biological pump”—a process where microscopic plants, often called phytoplankton, take up carbon and then die and sink into the deep ocean where carbon is stored for hundreds of years—to account for between 5 and 17% of the total increase in carbon uptake by the oceans by 2100.

Their findings were published today in the journal PNAS (Proceedings of the National Academy of Sciences), says Phys.org.

Lead author Dr. Jamie Wilson, of the University of Bristol’s School of Earth Sciences, explained, “The biological pump stores roughly double the amount of carbon dioxide that is currently in our atmosphere in the deep ocean. Because plankton are sensitive to climate change, this carbon pool is likely to change in size, so we set out to understand how this would change in the future in response to climate change by looking at the latest future projections by IPCC models.”

Microscopic organisms called plankton, living in the sunlit surface of the ocean, use carbon dioxide during photosynthesis. When these plankton die, their remains rapidly sink down through the “Twilight Zone” of the ocean (200–1000m), where environmental factors, such as temperature and oxygen concentration, and ecological factors, such as being eaten by other plankton, control how much reaches the deep ocean where the carbon from their bodies is stored away from the atmosphere for hundreds to thousands of years.

Warming of the oceans slows down the circulation, increasing the time that carbon is stored in the deep ocean.

Contributing author Dr. Anna Katavouta, who worked alongside early-career scientist Dr. Chelsey Baker, both from the National Oceanography Centre, added, “Our research found a consistent increase in the carbon stored in the ocean by the biological carbon pump over the 21st century in the latest IPCC model projections. In contrast, we found a decline in the global export production (the amount of organic matter, such as dead plankton, sinking below the ocean surface), which suggests that export production may not be as accurate a metric for the biological carbon pump than previously thought. We demonstrated that the organic matter flux at 1000 meters is instead a better predictor of long-term carbon sequestration associated with the biological carbon pump. This outcome will help us to better understand the processes that control the biological carbon pump and to predict more reliably how much of the carbon released due to human activity will be stored in the ocean in the future.”

However, the IPCC models have no consistent representation of the environmental and ecological processes in the Twilight Zone. This leads to a large uncertainty in how much carbon dioxide originating from the atmosphere the biological pump will store beyond the end of the century.

In theory, after 2100, carbon storage by the biological pump could stall and instead may start acting as a source of carbon dioxide to the atmosphere, which could exacerbate climate change further.

Full article here.

Image credit: interactivestars.com


Not exactly a new idea, but worth pursuing. Given the present feverish pursuit of supposedly climate-related policies that attempt to counter imagined human-caused effects, all known aspects of natural variation must be highlighted and included in models.
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New analysis suggests that the Moon might be an unappreciated factor in climate change and, according to researchers from the Universities of East Anglia and Reading, its influence “cannot be discounted as an important driver of multidecadal variability of global temperature.”

It’s a suggestion that is bound to prompt debate and a possible reassessment of the relative influence of human factors on climate change in the past and the future when the lunar effect is included, says Dr. David Whitehouse @ Net Zero Watch.

It arises from the so-called lunar nodal cycle of 18.6 years caused by variations in the angle of the Moon’s orbital plane. During this period the Moon’s orbit “wobbles” between plus or minus 5 degrees relative to the Earth’s equator.

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Arctic sea ice [image credit: cbc.ca]


The researchers find ‘a significantly declining AA effect on the millennial time scale’ — but then attempt to link that to anthropogenic forcing in recent times, according to the article at least. That seems illogical if the argument is that humans are playing a part. In any case if the effect has been shown to occur over at least a millennium, that in itself casts doubt on claims that humans must be the prime (or any) cause of the most recent observed changes.
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The recent amplified warming in the Arctic during the last decades has received much attention, says Phys.org.

But how Arctic amplification (AA) has varied on longer time scales and what drives these variations remain unclear.

Recently, a study has provided a new perspective on the AA effect during the past millennium based on the best available paleoclimate data and novel data assimilation methods.

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A portion of the Atlantic meridional overturning circulation [image credit: R. Curry, Woods Hole Oceanographic Institution @ Wikipedia]


Another supposed climate tipping point, popular with the alarm-loving media, floats away? A feature that’s “built into many models” was found not to work as advertised.
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Most simulations of our climate’s future may be overly sensitive to Arctic ice melt as a cause of abrupt changes in ocean circulation, according to new research led by scientists at the University of Wisconsin–Madison.

Climate scientists count the Atlantic Meridional Overturning Circulation (or AMOC) among the biggest tipping points on the way to a planetary climate disaster, says Phys.org.

The Atlantic Ocean current acts like a conveyor belt carrying warm tropical surface water north and cooler, heavier deeper water south.

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The signal that wasn’t found could be ‘masked’, researchers suggest. They expected ‘ongoing climate change’ to do something, but maybe it just wasn’t there? Cue more research.
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A new Met Office-led study – reviewing evidence from previous scientific papers and climate models – reveals natural patterns of weakening and strengthening of ocean currents which influence the UK’s weather and climate.

In the North Atlantic lies one of the world’s largest climate mechanisms: a system of currents transporting relatively warm water from the tropics to the poles, with return currents at depth transporting colder, denser water further south.

The transport of heat to the North Atlantic keeps the UK’s climate warmer than other locations at our latitude, says the Met Office.

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According to NOAA’s ENSO blog triple dip La Ninas are now on the menu of imminent possibilities.

Science Matters

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The post below updates the UAH record of air temperatures over land and ocean.  But as an overview consider how recent rapid cooling has now completely overcome the warming from the last 3 El Ninos (1998, 2010 and 2016).  The UAH record shows that the effects of the last one were gone as of April 2021, again in November, 2021 and now in January and February 2022. (UAH baseline is now 1991-2020).

For reference I added an overlay of CO2 annual concentrations as measured at Mauna Loa.  While temperatures fluctuated up and down ending flat, CO2 went up steadily by ~55 ppm, a 15% increase.

Furthermore, going back to previous warmings prior to the satellite record shows that the entire rise of 0.8C since 1947 is due to oceanic, not human activity.

gmt-warming-events

The animation is an update of a previous analysis from Dr. Murry Salby.  These graphs use Hadcrut4 and…

View original post 1,147 more words

Arctic sea ice [image credit: cbc.ca]


One finding was that snow cover variability was more ‘extreme’ than expected, pointing to the need for further research as well as improvements to climate models. Whether the recent Arctic weather/climate history is a reliable guide to future conditions remains to be seen.
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Hundreds of international researchers are currently analyzing observations from the one-year MOSAiC expedition, during which hundreds of environmental parameters were recorded with unprecedented accuracy and frequency over a full annual cycle in the Central Arctic Ocean, says Phys.org.

They have now published three overview articles on the MOSAiC atmosphere, snow and sea ice, and ocean programs in the journal Elementa, highlighting the importance of examining all components of the climate system together.

These results present the first complete picture of the climate processes in the central Arctic which is warming more than two times as fast as the rest of the planet—processes which affect weather and climate worldwide.

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Opposite sea ice trends? [Credits: NASA Goddard Space Flight Center/Joy Ng]


Climate modellers need yet more and bigger computers to stand a chance of eradicating faulty sea ice projections in the polar regions, apparently. Meanwhile, they believe there must be some ‘delay’ in their long-predicted but not (yet?) happening Antarctic sea ice decline. Quote: “Our study supports the hypothesis that climate models and projections of the Antarctic sea ice will be far more reliable as soon as they are capable of realistically simulating a high-resolution ocean, complete with eddies”.
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Despite global warming and the sea-ice loss in the Arctic, the Antarctic sea-ice extent has remained largely unchanged since 1979, says Eurekalert.

However, existing climate model-based simulations indicate significant sea-ice loss, contrary to actual observations.

As experts from the Alfred Wegener Institute have now shown, the ocean may weaken warming around Antarctica and delay sea-ice retreat.

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Antarctica


A key sentence to note in this report says: ‘Half of all carbon dioxide bound in the world’s oceans is found in the Southern Ocean.’ What impact does the outgassing have on the total carbon dioxide content of the atmosphere, which we’re expected to believe is a matter of huge climate concern requiring drastic and expensive measures for decades to come?
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Storms over the waters around Antarctica drive an outgassing of carbon dioxide into the atmosphere, according to a new international study with researchers from the University of Gothenburg. — Phys.org reporting.

The research group used advanced ocean robots for the study, which provides a better understanding of climate change and can lead to better global climate models.

The world’s southernmost ocean, the Southern Ocean that surrounds Antarctica, plays an important role in the global climate because its waters contain large amounts of carbon dioxide.

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Bioluminescence [image credit: Gov’t. of South Australia]


Such events happen because ‘the microbes can suddenly light up as if a switch were thrown’. Even the smallest occurrence can be ‘100 times larger than Manhattan’.
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The ocean has always glowed, says the NY Times (via bdnews24.com).

The Greeks and Romans knew of luminous sea creatures as well as the more general phenomenon of seawater that can light up in bluish-green colours.

Charles Darwin, as he sailed near South America on a dark night aboard the HMS Beagle, encountered luminescent waves. He called it “a wonderful and most beautiful spectacle.”

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This won’t exactly be music to the ears of the climate alarmist tendency, which prefers to claim that people somehow dictate the course of climate variations.
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The Sun’s energy affects our climate but its influence is often ignored as changes in its intensity are very small. Its effect might be subtle but over decadal periods it adds up to being significant as a series of recent papers show, says Net Zero Watch.

Scientists from the University of California, Irvine, the National Taiwan Normal University, and the Institute of Atmospheric Physics, of the Chinese Academy of Sciences, Beijing, find that the 11-year solar cycle has a significant correlation with sea surface temperature variations in the North-eastern Pacific.

They believe that the Sun’s influence is first seen and then amplified in the lower stratosphere, but it then alters the circulation in the troposphere which then affects the temperature of the ocean.

They note that the changes have a structure similar to that of the Pacific meridional mode – an interaction between trade winds and ocean evaporation which is an important trigger of the central Pacific (CP) type of the El Niño-Southern Oscillation (ENSO).

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A portion of the Atlantic meridional overturning circulation [image credit: R. Curry, Woods Hole Oceanographic Institution @ Wikipedia]


This article starts off confident that the researchers are right – ‘we now know’ etc. – but later retreats and says ‘the cooling appears to have’ etc. But as the Little Ice Age is an interesting topic it’s worth a look.
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New research from the University of Massachusetts Amherst provides a novel answer to one of the persistent questions in historical climatology, environmental history and the earth sciences: what caused the Little Ice Age?

The answer, we now know, is a paradox: warming, says Phys.org.

The Little Ice Age was one of the coldest periods of the past 10,000 years, a period of cooling that was particularly pronounced in the North Atlantic region.

This cold spell, whose precise timeline scholars debate, but which seems to have set in around 600 years ago, was responsible for crop failures, famines and pandemics throughout Europe, resulting in misery and death for millions.

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The ocean carbon cycle [credit: IAEA]


Having much better information about how nature’s carbon cycle is working, before attempting to apply random expensive schemes of uncertain impact to try and alter it, would surely be a sound approach, as the researchers suggest. Surprises might not be welcome ones.
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The Southern Ocean is a significant carbon sink says Phys.org, absorbing a large amount of the excess carbon dioxide emitted into the atmosphere by human activities, according to a new study led by the National Center for Atmospheric Research (NCAR).

The findings provide clarity about the role the icy waters surrounding Antarctica play in buffering the impact of increasing greenhouse gas emissions, after research published in recent years suggested the Southern Ocean might be less of a sink than previously thought.

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Fram Strait is the only deep passage between the Arctic and World Oceans [credit: Bdushaw @ Wikipedia]


Twenty six ‘COP’s and much of the world still claims to believe in, and frames its energy and various other policies according to, flawed climate models? If ‘rapid’ Arctic warming was already happening 120 years ago at an early stage of industrialisation what was, or were, the cause(s)?
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The Arctic Ocean has been getting warmer since the beginning of the 20th century – decades earlier than records suggest – due to warmer water flowing into the delicate polar ecosystem from the Atlantic Ocean.

An international group of researchers reconstructed the recent history of ocean warming at the gateway to the Arctic Ocean in a region called the Fram Strait, between Greenland and Svalbard, says SciTech Daily.

Using the chemical signatures found in marine microorganisms, the researchers found that the Arctic Ocean began warming rapidly at the beginning of the last century as warmer and saltier waters flowed in from the Atlantic – a phenomenon called Atlantification – and that this change likely preceded the warming documented by modern instrumental measurements.

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Credit: NOAA

Researchers propose another weather/climate cycle.
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A team of researchers with members affiliated with a large number of institutions across Japan has found that the Gulf stream and Kuroshio are synchronized on a decadal time scale, says Phys.org.

In their paper published in the journal Science, the group describes their study of decades of weather satellite data and the link between the two ocean currents.

Paola Cessi, with the Scripps Institution of Oceanography at the University of California, has published a Perspective piece on the work done by the team in Japan in the same journal issue.

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Halfway through this article we see the study’s findings were made ‘where increases in sea surface temperatures have been recorded because of the reversal of a climatic condition called the Pacific Decadal Oscillation, with likely connections to global climate change’. So the PDO has changed, which it regularly will do as its name (‘decadal’) indicates, and they want to tie the consequences to humans? That seems to be implied, although left vague by the usual catch-all term ‘climate change’.
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WASHINGTON—Warming ocean waters have caused a drop in the brightness of the Earth, according to a new study, says Eurekalert.

Researchers used decades of measurements of earthshine — the light reflected from Earth that illuminates the surface of the Moon to find that there has been a significant drop in Earth’s reflectance over the past two decades.

The Earth is now reflecting about half a watt less light per square meter than it was 20 years ago, with most of the drop occurring in the last three years of earthshine data, according to the new study in the AGU journal Geophysical Research Letters, which publishes high-impact, short-format reports with immediate implications spanning all Earth and space sciences.

That’s the equivalent of 0.5% decrease in the Earth’s reflectance. Earth reflects about 30% of the sunlight that shines on it.

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ENSO1

Credit: concernusa.org

A key premise of most computer models seems to be that the atmosphere, with its 0.04% CO2 content, drives ocean temperatures. As most of the energy is in the oceans, why wouldn’t it be the other way round?
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The cycling between warm El Niño and cold La Niña conditions in the eastern Pacific (commonly referred to as the El Niño-Southern Oscillation, ENSO) has persisted without major interruptions for at least the last 11,000 years, says Phys.org.

This may change in the future according to a new study published in the journal Nature Climate Change by a team of scientists from the IBS Center for Climate Physics (ICCP) at Pusan National University in South Korea, the Max Planck Institute of Meteorology, Hamburg, Germany, and the University of Hawaiʻi at Mānoa, U.S.

The team conducted a series of global climate model simulations with an unprecedented spatial resolution of 10 km in the ocean and 25 km in the atmosphere.

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AMOC_circ

A portion of the Atlantic meridional overturning circulation [image credit: R. Curry, Woods Hole Oceanographic Institution @ Wikipedia]

Widely differing climate models are supposed to be a reliable guide to the future? Clearly not. Here the uncertainty gets investigated, and pinned on a phenomenon that was recently claimed by Mann et al not to exist. Of course all these models make the assumption that carbon dioxide at a tiny 0.04% of the atmosphere is a key variable of concern, despite all the other variability in the climate system that they have to wrestle with.
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Thirty state-of-the-art IPCC-climate models predict dramatically different climates for the Northern Hemisphere, especially Europe, says Phys.org.

An analysis of the range of responses now reveals that the differences are mostly down to the individual model’s simulations of changes to the North Atlantic ocean currents and not only—as normally assumed—atmospheric changes.

The work, by Katinka Bellomo, National Research Council of Italy, Institute of Atmospheric Sciences and Climate, and colleagues is published today in Nature Communications and is part of the European science collaboration, TiPES, coordinated by the University of Copenhagen.

All climate models vary in the details. Variables such as atmospheric pressure, cloud cover, temperature gradients, sea surface temperatures, and many more are tuned to interact slightly differently for every model. This means that the predictions of the many models also vary.

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