Science Current Events | Science News | Brightsurf.com
 
Email a Friend Send to a friend
Printer Friendly Print Icy calculations on a hot topic

Icy calculations on a hot topic

September 11, 2007

University of Utah mathematicians have arrived at a new understanding of how salt-saturated ocean water flows through sea ice - a discovery that promises to improve forecasts of how global warming will affect polar icepacks.

In the current issue of the journal Geophysical Research Letters, math Professor Ken Golden and colleagues show that brine moving up or down through floating sea ice follows "universal transport properties."




"It means that almost the exact same formulas describing how water flows through sedimentary rocks in the Earth's crust apply to brine flow in sea ice, even though the microstructural details of the rocks are quite different from sea ice," says Golden, who currently is on an Australian research ship in Antarctica.

The study suggests similar porous materials - including ice on other worlds, such as Jupiter's icy ocean-covered moon Europa - should follow the same rules, he adds.

Golden has made several trips to Antarctica and the Arctic for his studies.

The American Geophysical Union, which publishes the journal carrying Golden's study, says sea ice is important because it is both "an indicator and regulator of climate change; its thinning and retreat show the effects of climate warming, and its presence greatly reduces solar heating of the polar oceans."

"Sea ice also is a primary habitat for microbial communities, sustaining marine food webs," the group adds. "The permeability of sea ice and its ability to transport brine are important to many problems in geophysics and biology, yet remain poorly understood."

The AGU says Golden's study presents "a unified picture of sea ice permeability," and how that permeability to brine flow varies with the temperature and salinity of the ice.

Icy Math and Climate Change

"One of the most important aspects of the polar sea ice packs is the role they play in Earth's albedo - whether Earth absorbs or reflects incoming solar radiation," says Golden. "White sea ice reflects; the ocean absorbs. In the late spring, melt ponds [atop the ice] critically affect the albedo of the polar ice packs. The drainage of these melt ponds is again largely controlled by the permeability of the ice."

The Intergovernmental Panel on Climate Change's predictions "that the summer Arctic ice pack may disappear sometime during 2050-2100 depend in part on these types of considerations," he adds. "Now that we have a much firmer understanding of how permeability depends on the variables of sea ice, namely temperature and salinity, our results can help to provide more realistic representations of sea ice in global climate models, helping to hone the predictions for world climate and the effects of warming."

The results "can also help in understanding how polar ecosystems respond to climate change," Golden says. "Biological processes in the polar regions depend on brine flow through sea ice. For example, the rich food webs in the polar oceans are based on algae and bacteria living in the ice, and their nutrient intake is controlled by brine flow."

"In the Antarctic, ice formed from flooding of ice surfaces is an important component of the ice pack, and this formation is dependent on brine flow," he adds. "Brine drainage out of sea ice and the subsequent formation of Antarctic bottom water is an important part of the world's oceans."

Golden says the formulas that describe brine flow through sea ice and groundwater flow through sediments arose from abstract solid-state physics models used to describe atomic-scale phenomena in metals.

"These formulas exhibit universality, meaning that the end result doesn't depend on the details of the model or system, only on the dimension of the system," he says. "While large classes of abstract models obey this principle, real materials often do not. So it is surprising that a complex, real material like sea ice actually obeys these formulas."

To conduct the study, Golden and colleagues analyzed sea ice and "modeled" or simulated its behavior mathematically, and also made field and laboratory measurements of sea ice, including using X-rays to make CT-scan images of how the microscopic pore structure of ice varies with temperature.

University of Utah



Related Sea Ice Current Events and Sea Ice News Articles Sea Ice Current Events and Sea Ice News RSS Sea Ice Current Events and Sea Ice News RSS
Cave Study Links Climate Change to California Droughts
California experienced centuries-long droughts in the past 20,000 years that coincided with the thawing of ice caps in the Arctic.

Last time carbon dioxide levels were this high: 15 million years ago, scientists report
You would have to go back at least 15 million years to find carbon dioxide levels on Earth as high as they are today, a UCLA scientist and colleagues report Oct. 8 in the online edition of the journal Science.

NASA flies to Antarctica for largest airborne polar ice survey
NASA begins a series of flights Oct. 15 to study changes to Antarctica's sea ice, glaciers and ice sheets. The flights are part of Operation Ice Bridge, a six-year campaign that is the largest airborne survey ever made of ice at Earth's polar regions.

Peering under the ice of a collapsing polar coast
Starting this month, a giant NASA DC-8 aircraft loaded with geophysical instruments and scientists will buzz at low level over the coasts of West Antarctica, where ice sheets are collapsing at a pace far beyond what scientists expected a few years ago.

Arctic sea ice recovers slightly in 2009, remains on downward trend, says U. of Colorado report
Despite a slight recovery in summer Arctic sea ice in 2009 from record-setting low years in 2007 and 2008, the sea ice extent remains significantly below previous years and remains on a trend leading toward ice-free Arctic summers, according to the University of Colorado at Boulder's National Snow and Ice Data Center.

Arctic Sea ice extent is third lowest on record
U.S. satellite measurements show Arctic sea ice extent in 2009 - the area of the Arctic Ocean covered by floating ice - was the third lowest since satellite measurements were first made in 1979.

Algae and pollen grains provide evidence of remarkably warm period in Antarctica's history
For Sophie Warny, LSU assistant professor of geology and geophysics and curator at the LSU Museum of Natural Science, years of patience in analyzing Antarctic samples with low fossil recovery finally led to a scientific breakthrough.

Arctic sea ice reaches minimum extent for 2009, third lowest ever recorded
The Arctic sea ice cover appears to have reached its minimum extent for the year, the third-lowest recorded since satellites began measuring sea ice extent in 1979, according to the University of Colorado at Boulder's National Snow and Ice Data Center.

UA scientists seek new emphases in Arctic climate change research
Much of circumpolar Arctic research focuses on the physical, direct changes resulting from climate warming such as sea ice retreat and temperature increases.

Satellites and submarines give the skinny on sea ice thickness
This summer, a group of scientists and students - as well as a Canadian senator, a writer, and a filmmaker - set out from Resolute Bay, Canada, on the icebreaker Louis S. St-Laurent.
More Sea Ice Current Events and Sea Ice News Articles
Sea Ice: An Intorduction to its Physics, Chemistry, Biology and Geology

Sea Ice: An Intorduction to its Physics, Chemistry, Biology and Geology
by David N. Thomas (Editor), G. S. Dieckmann (Editor)

Sea ice, which covers up to 7% of the planet’s surface, is a major component of the world’s oceans, partly driving ocean circulation and global climate patterns. It provides a habitat for a rich diversity of marine organisms, and is an extremely valuable source of information in studies of global climate change and the evolution of present day life forms. Increasingly sea ice is being used as a proxy for extraterrestrial ice covered systems.


Sea Ice provides a comprehensive review of our current available knowledge of polar pack ice, the study of which is severely constrained by the logistic difficulties of working in such harsh and remote regions of the earth. The book’s editors, Drs Thomas and Dieckmann have drawn together an impressive group of international...

Sea Ice

Sea Ice
by David N. Thomas (Editor), Gerhard S. Dieckmann (Editor)

As the Arctic perennial sea ice continues to disappear at an alarming rate, a full understanding of sea ice as a crucial global ecosystem, and the effects of its loss is vital for all those working with and studying global climate change.

Building on the success of the previous edition, the second edition of Sea Ice, now much expanded and in full colour throughout, includes six completely new chapters with complete revisions of all the chapters included from the first edition.

The Editors, Professor David Thomas and Dr Gerhard Dieckmann have once again drawn together an extremely impressive group of internationally respected contributing authors, ensuring a comprehensive worldwide coverage of this incredibly important topic.

Sea  Ice, second edition, is an...

3 Silicone Ice Tray Sea Shaped Cube Mold Party Fun New

3 Silicone Ice Tray Sea Shaped Cube Mold Party Fun New
by 4 Seasons

3 Brand New Silicone Ice Cube Trays. These durable trays have sea life shapes that give your ice you a fun look! Flexible and easy to use. Freezer and refrigerator safe. Easy to wash. Each tray makes: 2 crabs 2 nutmeg shells 2 sea stars 2 scallop shells Perfect for parties and for kids! Available colors: Green, Orange & Blue. Measures: 4.25" W 8.75" L x 1" H Cube size:1.5" x 1.5" x 1" (approx.) Sealed in original package.

Nature: Under Antarctic Ice/Encountering Sea Monsters [Blu-ray]

Nature: Under Antarctic Ice/Encountering Sea Monsters [Blu-ray]
Starring: Hilary Swank, Tim Matheson
Directed By: NATURE produced by WNET

Program 1: Under Antarctic Ice - Beneath the surface of stunningly cold water, an abundance of lifeforms and icescapes can be found. Academy Award-winner Hilary Swank narrates encounters with jellyfish that have thirty-foot long tentacles, sponges the size of large mammals, killer whales, and more in this fascinating look at what lies in the ocean depths beneath the surface of one of the coldest continents on Earth.

Program 2: Encountering Sea Monsters - Enter the gloomy green ocean depths with deep-sea cameraman Bob Cranston to discover fantastic worlds and the beautiful but deadly creatures that inhabit them. Nothing in science fiction can prepare you for a creature with a beak like a parrot, no bones in its body, three hearts, blue blood, skin that can change colors, and arms...

Diesel Men's Ice Cool Lace-up Sneaker,White/Turkish Sea,13 M US

Diesel Men's Ice Cool Lace-up Sneaker,White/Turkish Sea,13 M US
by Diesel



Piggy Polish Toe Nail Polish, Polar Sea Ice

Piggy Polish Toe Nail Polish, Polar Sea Ice
by Piggy Polish

A fun, colorful way to show off your toes! Professional quality, long lasting toe nail polish.

Ship of Ice

Ship of Ice
Directed By: Peter Lynch
Also With: John Davis (Producer), Eco-Nova Productions Ltd. (Producer), Thor Henrikson (Writer)



  Hotpuppy So Many Fish in the Sea Tee in Ice Grey in XX-Large
by Hotpuppy



Fire N and Ice Dragons Mega Bloks Fyren Sea Phoenix Warship

Fire N and Ice Dragons Mega Bloks Fyren Sea Phoenix Warship
by Mega Bloks

Part of the Fire Ice Dragons Mega Bloks collection, the Fyren Sea Phoenix is a 210-piece building set that will launch your imagination into the land of dragons!

SEA ICE 1/4 OZ ANTI FOG

SEA ICE 1/4 OZ ANTI FOG
by MCNETT

THUNDER SHIELD SPRAY
Specialized liquid formula provides gentle cleaning. Easy in-field application. Safe for all glass and plastic lenses. Limited quantity on Sea Ice Anti Fog.


© 2009 BrightSurf.com