. 24/7 Space News .
ICE WORLD
Winter is coming: Researchers uncover the surprising cause of the little ice age
by Staff Writers
Amherst MA (SPX) Dec 17, 2021

Multimodel mean correlation map between the low-frequency AMOC at 26 N and SST (12). Stars numbered 1 to 15 denote location of sites.

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.

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.

To date, the mechanisms that led to this harsh climate state have remained inconclusive. However, a new paper published recently in Science Advances gives an up-to-date picture of the events that brought about the Little Ice Age. Surprisingly, the cooling appears to have been triggered by an unusually warm episode.

When lead author Francois Lapointe, postdoctoral researcher and lecturer in geosciences at UMass Amherst and Raymond Bradley, distinguished professor in geosciences at UMass Amherst began carefully examining their 3,000-year reconstruction of North Atlantic sea surface temperatures, results of which were published in the Proceedings of the National Academy of Sciences in 2020, they noticed something surprising: a sudden change from very warm conditions in the late 1300s to unprecedented cold conditions in the early 1400s, only 20 years later.

Using many detailed marine records, Lapointe and Bradley discovered that there was an abnormally strong northward transfer of warm water in the late 1300s which peaked around 1380. As a result, the waters south of Greenland and the Nordic Seas became much warmer than usual. "No one has recognized this before," notes Lapointe.

Normally, there is always a transfer of warm water from the tropics to the arctic. It's a well-known process called the Atlantic Meridional Overturning Circulation (AMOC), which is like a planetary conveyor belt. Typically, warm water from the tropics flows north along the coast of Northern Europe, and when it reaches higher latitudes and meets colder arctic waters, it loses heat and becomes denser, causing the water to sink at the bottom of the ocean. This deep-water formation then flows south along the coast of North America and continues on to circulate around the world.

But in the late 1300s, AMOC strengthened significantly, which meant that far more warm water than usual was moving north, which in turn cause rapid arctic ice loss. Over the course of a few decades in the late 1300s and 1400s, vast amounts of ice were flushed out into the North Atlantic, which not only cooled the North Atlantic waters, but also diluted their saltiness, ultimately causing AMOC to collapse. It is this collapse that then triggered a substantial cooling.

Fast-forward to our own time: between the 1960s and 1980s, we have also seen a rapid strengthening of AMOC, which has been linked with persistently high pressure in the atmosphere over Greenland. Lapointe and Bradley think the same atmospheric situation occurred just prior to the Little Ice Age-but what could have set off that persistent high-pressure event in the 1380s?

The answer, Lapointe discovered, is to be found in trees. Once the researchers compared their findings to a new record of solar activity revealed by radiocarbon isotopes preserved in tree rings, they discovered that unusually high solar activity was recorded in the late 1300s. Such solar activity tends to lead to high atmospheric pressure over Greenland.

At the same time, fewer volcanic eruptions were happening on earth, which means that there was less ash in the air. A "cleaner" atmosphere meant that the planet was more responsive to changes in solar output. "Hence the effect of high solar activity on the atmospheric circulation in the North-Atlantic was particularly strong," said Lapointe.

Lapointe and Bradley have been wondering whether such an abrupt cooling event could happen again in our age of global climate change. They note that there is now much less arctic sea ice due to global warming, so an event like that in the early 1400s, involving sea ice transport, is unlikely.

"However, we do have to keep an eye on the build-up of freshwater in the Beaufort Sea (north of Alaska) which has increased by 40% in the past two decades. Its export to the subpolar North Atlantic could have a strong impact on oceanic circulation", said Lapointe.

"Also, persistent periods of high pressure over Greenland in summer have been much more frequent over the past decade and are linked with record-breaking ice melt. Climate models do not capture these events reliably and so we may be underestimating future ice loss from the ice sheet, with more freshwater entering the North Atlantic, potentially leading to a weakening or collapse of the AMOC." The authors conclude that there is an urgent need to address these uncertainties.

Research Report: "Little Ice Age abruptly triggered by intrusion of Atlantic waters into the Nordic Seas"


Related Links
University of Massachusetts Amherst
Beyond the Ice Age


Thanks for being there;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Monthly Supporter
$5+ Billed Monthly


paypal only
SpaceDaily Contributor
$5 Billed Once


credit card or paypal


ICE WORLD
New study reconstructs preglacial topography of mid-North America for first time
Indianapolis IN (SPX) Dec 17, 2021
What did North America look like before ice-sheets streamed across it, carving out lakes and flattening fields? For the first time, a research team including IU scientists has reconstructed a view of North America's mid-continent, before glaciers changed the landscape forever. The researchers say their findings enable better understanding of how ice and land co-evolve and illuminate some key climate change questions, including what may happen as current continental ice sheets respond to clim ... read more

Comment using your Disqus, Facebook, Google or Twitter login.



Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

ICE WORLD
NASA selects second private astronaut mission to Space Station

Space Habitat Market size to grow by USD 94.92 Bn

Blue Origin plans to launch largest crew yet Saturday

Father's foundry job inspires Dr. Sharon Cobb to pursue NASA career path

ICE WORLD
BWXT Delivers Fuel to NASA to Support Nuclear Thermal Propulsion

Rocket Lab launches 109th satellite to orbit

Spire Global selects Virgin Orbit for late-load addition to next flight

Orbex begins construction of new rocket launchpad in the UK

ICE WORLD
NASA's eventual farewell to tiny Mars helicopter could be emotional

Mars helicopter Ingenuity ready to fly again as radio link is restored

ExoMars discovers hidden water in Mars' Grand Canyon

To Seitah and Back

ICE WORLD
First crew of space station provide a full update on China's progress

Milestone mission for China's first commercial rocket company

Chinese astronauts to give space lecture on Dec. 9

China to livestream first space class from Tiangong space station

ICE WORLD
Kleos' Patrol Mission Satellites Ready and Shipped to Launch Site

Europe opens up a new space to commercial services

Airbus and DLR intensify cooperation

Growing trend shows demand for maintenance students at commercial space firms

ICE WORLD
Understanding cobalt's human cost

New smart-roof coating enables year-round energy savings

Nike buys virtual sneaker firm as metaverse buzz grows

Technique enables real-time rendering of scenes in 3D

ICE WORLD
Life arose on hydrogen energy

Stellar "ashfall" could help distant planets grow

"Newer, nimbler, faster:" Venus probe will search for signs of life in clouds of sulfuric acid

ESO telescope images planet around most massive star pair to date

ICE WORLD
Planet decision that booted out Pluto is rooted in folklore, astrology

Are Water Plumes Spraying from Europa

Science results offer first 3D view of Jupiter's atmosphere

Juno peers deep into Jupiter's colorful belts and zones









The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us.