Extreme weather phenomena called atmospheric rivers were behind intense snowstorms recorded in 2009 and 2011 in East Antarctica. The resulting snow accumulation partly offset recent ice loss from the Antarctic ice sheet, report researchers from KU Leuven.
Atmospheric rivers are long, narrow water vapour plumes stretching thousands of kilometres across the sky over vast ocean areas. They are capable of rapidly transporting large amounts of moisture around the globe and can cause devastating precipitation when they hit coastal areas.
Although atmospheric rivers are notorious for their flood-inducing impact in Europe and the Americas, their importance for Earth’s polar climate – and for global sea levels – is only now coming to light.
In this study, an international team of researchers led by Irina Gorodetskaya of KU Leuven’s Regional Climate Studies research group used a combination of advanced modelling techniques and data collected at Belgium’s Princess Elisabeth polar research station in East Antarctica’s Dronning Maud Land to produce the first ever in-depth look at how atmospheric rivers affect precipitation in Antarctica.
The researchers studied two particular instances of heavy snowfall in the East Antarctic region in detail, one in May 2009 and another in February 2011, and found that both were caused by atmospheric rivers slamming into the East Antarctic coast.
The Princess Elisabeth polar research station recorded snow accumulation equivalent to up to 5 centimetres of water for each of these weather events, good for 22 per cent of the total annual snow accumulation in those years.
The findings point to atmospheric rivers’ impressive snow-producing power. “When we looked at all the extreme weather events that took place during 2009 and 2011, we found that the nine atmospheric rivers that hit East Antarctica in those years accounted for 80 per cent of the exceptional snow accumulation at Princess Elisabeth station,” says Irina Gorodetskaya.
And this can have important consequences for Antarctica’s diminishing ice sheet. “There is a need to understand how the flow of ice within Antarctica’s ice sheet responds to warming and gain insight in atmospheric processes, cloud formation and snowfall,” adds Nicole Van Lipzig, co-author of the study and professor of geography at KU Leuven.
A separate study found that the Antarctic ice sheet has lost substantial mass in the last two decades – at an average rate of about 68 gigatons per year during the period 1992-2011.
“The unusually high snow accumulation in Dronning Maud Land in 2009 that we attributed to atmospheric rivers added around 200 gigatons of mass to Antarctica, which alone offset 15 per cent of the recent 20-year ice sheet mass loss,” says Irina Gorodetskaya.
“This study represents a significant advance in our understanding of how the global water cycle is affected by atmospheric rivers. It is the first to look at the effect of atmospheric rivers on Antarctica and to explore their role in cryospheric processes of importance to the global sea level in a changing climate,” says Martin Ralph, contributor to the study and Director of the Center for Western Weather and Water Extremes at the University of California, San Diego.
“Moving forward, we aim to explore the impact of atmospheric rivers on precipitation in all Antarctic coastal areas using data records covering the longest possible time period. We want to determine exactly how this phenomenon fits into climate models,” says Irina Gorodetskaya.
“Our results should not be misinterpreted as evidence that the impacts of global warming will be small or reversed due to compensating effects. On the contrary, they confirm the potential of the Earth’s warming climate to manifest itself in anomalous regional responses. Thus, our understanding of climate change and its worldwide impact will strongly depend on climate models’ ability to capture extreme weather events, such as atmospheric rivers and the resulting anomalies in precipitation and temperature,” she concludes.
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The study, “The role of atmospheric rivers in anomalous snow accumulation in East Antarctica”, was published recently in the American Geophysical Union’s Geophysical Research Letters. Co-authors are Nicole Van Lipzig (Regional Climate Studies research group, KU Leuven), Kim Claes (KU Leuven graduate student), Maria Tsukernik (Brown University), Martin Ralph (University of California San Diego) and William Neff (University of Colorado Boulder).
@ur momisugly Jon Philip Peterson 9:28
What do I tell my close friends who believe all this as gospel??
If you like your doctor, you can keep your doctor.
If you like your health plan, you can keep it.
There are more of those.
@ur momisugly Jon Philip Peterson 9:28
‘The Pentagon says that climate change poses immediate risks to our national security. We should act like it.’
That’s why we armed ISIS?
The Pentagon says that because as Commander In Chief, Obama told the Pentagon to say that…
In the same time frame that Iran continued building nuclear weapons,
that Israel was bombarded by almost 6000 rockets randomly aimed at its cities and houses fired from within its enemies’ neighborhoods,
when North Korea continued rocket and nuclear bomb technology,
when Communist China exceeded American economic development and weapons design and fabrication,
when Communist China economically bought out resources across Africa,
when Russia isolated then cut off all of Europe’s natural gas supply and transcontinental oil pipelines,
when Canada’s energy exports were laid up in isolation by 15 years of “study”,
when Venezuela and Cuba lost their Communist economies and long-time communist leaders,
when Central America crossed our borders by invitation with 15 million (or was it 32 million) illegal aliens,
when Muslim extremists committed over 24,000 separate acts of Islam terrorism and violence against more than 109,000 individuals …
when American and Western economies have been mired in 8 years of continuous economic recession and loss BECAUSE of the administration’s own energy and economic policies,
when 57% of American households are depending not on jobs for their salaries but on monthly government paychecks and welfare,
when the Russian economy is collapsing back into Communism (and pulling other nations back into its dictatorship!),
our Secretary of State and President and their “team” of White House “leaders” have declared a 2/10 of one degree increase in weather over an 18 year period “the most important international risk to our national security” …
Do we need to say more about who controls the national “RESET” button on national security?
Just how long political leaders and media elites will succeed in persuading the majority that the climate is warming, when in fact it is beginning to cool, will be the best possible illustration of the limitations of, and the real nature of, human “intellect” and sentience.
Of the spectacular communal logical fallacies of which we are capable.
And of the underlying fact that most people prefer fabricated reality, however absurd, to actual reality.
The grotesquely bulbous head, complex social behaviour and appearance of intelligence in H. “sapiens” evolved to deceive and manipulate primarily, for the purpose of maximal social control by psychological violence.
To use these faculties to educate and enrich one’s fellow person is a better use of them,
but is a redirection from their primary evolutionary purpose.
Good needs to subvert evil.
With real intelligence, real science can subvert politicized manipulative pseudo-science.
The heart of man is deceitful above all things, and desperately sick.
Who can understand it?
(Jeremiah)
More meridional jet streams and atmospheric high pressure cells causing ‘blocking’ events are the features that give rise to more persistent and longer ‘rivers’ of precipitation which allow more warm air towards the poles and more air from the poles across middle latitudes.
One sees more of such phenomena when the sun is less active leading to an expansion of the polar air masses at the surface in the form of ‘negative’ Arctic and Antarctic Oscillations.
It is a sign that global cooling will eventually follow when the increased cloudiness from longer and more persistent such ‘rivers’ has had time to reduce solar energy into the oceans.
Rossby waves, of the kind Stephen refers to, have been studied to determine their origin. There is substantial evidence that these occurrences are triggered from below though rotation effects on our soupy atmosphere and oceanic-atmospheric teleconnections. The following powerpoint might help educate readers and give pause to Stephen’s oft repeated Solar connection.
http://www.gfd-dennou.org/arch/fdeps/2012-11-18/01_shepherd/lecture03/pub-web/20121119_shepherd_lec03.pdf
You need a top down solar effect in addition to the bottom up ocean effect (via Rossby waves) to account for longer term climate changes such as MWP and LIA.
Rossby waves cannot be the complete story.
This reminds me how H. H. Lamb explained the changed pattern of air flow during the Little Ice Age.
Billis Illis posted this clip a few years ago in the middle of an enlightening rant about what a rotating sphere with an atmosphere does.:
You can see the clouds peeling away from the tropics like smoke from a cigarette, then flowing towards the poles like a poorly confined “river.”
“Atmospheric river” is a reasonable and informative phrase, because it helps people picture the process of water flowing in the atmosphere.
Of course, the best way to picture it is to watch the clip of global circulation. That seems to show–for 2010–most of the precipitation from “atmospheric rivers” falling on Marie Byrd Land rather than Queen Maud Land.
“On the contrary, they confirm the potential of the Earth’s warming climate to manifest itself in anomalous regional responses.”
Anomalous regional responses? I wonder what data they have to support that statement? Or does an anomalous regional response mean whatever the writer wants it to mean.
If Antarctica was losing land-ice at a greater rate than average, it would show up as a change of the 4000 yr, steady, meager rate of sea-level rise.
Instead the rate of sea level rise is slowing.
If the polynomial trend fit to the U Colorado data were to continue it would stop increasing in about 150 years.