Free Newsletters - Space News - Defense Alert - Environment Report - Energy Monitor
. Earth Science News .




WHITE OUT
Snow melts faster under trees than in open areas in mild climates
by Michelle Ma for UW News
Seattle WA (SPX) Nov 19, 2013


A mounted camera shows snow sticking in an open area, while it appears to have melted under the trees in dense, second-growth forest just behind. Image courtesy University of Washington.

It's a foggy fall morning, and University of Washington researcher Susan Dickerson-Lange pokes her index finger into the damp soil beneath a canopy of second-growth conifers. The tree cover is dense here, and little light seeps in among the understory of the Cedar River Municipal Watershed about 30 miles east of Seattle.

She digs a small hole in the leaf-litter soil, then pushes a thumb-sized device, called an iButton, about an inch beneath the surface. If all goes well, this tiny, battery-powered instrument will collect a temperature reading every hour for 11 months. Researchers hope this tool and a handful of other instruments will help them map winter temperatures throughout the watershed as they track snow accumulation and melt.

This fieldwork piggybacks on a recent finding by Jessica Lundquist, a UW associate professor of civil and environmental engineering, and her lab that shows that tree cover actually causes snow to melt more quickly on the western slopes of the Pacific Northwest's Cascade Mountains and other warm, Mediterranean-type climates around the world.

Alternatively, open, clear gaps in the forests tend to keep snow on the ground longer into the spring and summer. Lundquist and her colleagues published their findings online this fall in Water Resources Research.

Common sense says that the shade of a tree will help retain snow, and snow exposed to sunlight in open areas will melt. This typically is the case in regions where winter temperatures are below freezing, such as the Northeast, Midwest and most of central and eastern Canada.

But in Mediterranean climates - where the average winter temperatures usually are above 30 degrees Fahrenheit - a different phenomenon occurs. Snow tends to melt under the tree canopy and stay more intact in open meadows or gaps in a forest.

This happens in part because trees in warmer, maritime forests radiate heat in the form of long-wave radiation to a greater degree than the sky does. Heat radiating from the trees contributes to snow melting under the canopy first.

"Trees melt our snow, but it lasts longer if you open up some gaps in the forest," Lundquist said. "The hope is that this paper gives us more of a global framework for how we manage our forests to conserve snowpack."

For the study, Lundquist examined relevant published research the world over that listed paired snow measurements in neighboring forested and open areas; then she plotted those locations and noted their average winter temperatures. Places with similar winter climates - parts of the Swiss Alps, western Oregon and Washington, and the Sierra Nevada range in California - all had similar outcomes: Snow lasted longer in open areas.

"It's remarkable that, given all the disparities in these studies, it did sort out by climate," Lundquist said.

Even in the rainy Pacific Northwest, we depend on yearly snowpack for drinking water and healthy river flows for fish, said Rolf Gersonde, who designs and implements forest restoration projects in the Cedar River Watershed. Reservoirs in the western Cascades hold approximately a year's supply of water.

That means when our snowpack is gone - usually by the summer solstice - our water supply depends on often meager summer rainfall to get us through until fall, he said. Snowpack is a key component of the Northwest's reservoir storage system, so watershed managers care about how forest changes due to management decisions or natural disturbances may impact that melting timetable.

The UW's research in the watershed has been a beneficial partnership, researchers say. The 90,000-acre watershed is owned by the City of Seattle and provides drinking water to 1.4 million people. The area now is closed to recreation and commercial logging, but more than 80 percent of the land was logged during the early 20th century, and a large swath of dense, second-growth trees grows there now.

Watershed managers have tried thinning and cutting gaps in parts of the forest to encourage more tree and plant diversity - that then leads to more diverse animal habitat - offering the UW a variety of sites to monitor.

The UW researchers acknowledge that temperature is a very broad predictor of snowmelt behavior, yet they expect their theory to hold true as they look more closely at the relationship between climate and snowmelt throughout the Pacific Northwest. They are collaborating with researchers at Oregon State University and the University of Idaho, and are ramping up a citizen science project asking hikers and snowshoers to share snow observations.

"This is really just a start," said Dickerson-Lange, a doctoral student in Lundquist's lab who is coordinating the citizen-science observations. "The plan is to refine this model. With climate change, a cold forest now might behave more like a warm forest 100 years from now. We want to be able to plan ahead."

Co-authors of the recent paper are Nicoleta Cristea of UW civil and environmental engineering and James Lutz of Utah State University.

.


Related Links
University of Washington
It's A White Out at TerraDaily.com






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

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




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





WHITE OUT
Police detain environment activist in Sochi
Moscow (AFP) Oct 31, 2013
Police in Russia's Sochi on Thursday briefly detained a prominent environmental activist critical of Olympic development in the city, accusing him of slandering a judge. But the activist, Andrei Rudomakha, who coordinates the regional NGO Environmental Watch on North Caucasus (EWNC) , dismissed the case as a pressure tactic by the authorities, the latest in a series of incidents targeting t ... read more


WHITE OUT
'Help Us': Isolated typhoon victims clamour for food

Japan sending almost 1,200 troops to typhoon-hit Philippines

Law and order prevailing in Philippine typhoon chaos

Aquino asserts control over typhoon relief effort

WHITE OUT
UNH scientists document, quantify deep-space radiation hazards

Bayanat Airports And Lockheed To Deploy Windtracer Lidar In Middle East

Czech gold deposits make foreign prospectors drool

Protection Of Materials And Structures From Space Environment at ICPMSE 11

WHITE OUT
Scientists create a low-cost, long-lasting water splitter made of silicon and nickel

New generation of micro sensors for monitoring ocean acidification

Island biodiversity in danger of total submersion with climate change

Largest lake in Britain and Ireland has lost three-quarters of winter water birds

WHITE OUT
Could volcanoes be causing Antarctic ice loss?

Brazil hails Russian bail for held Greenpeace militant

Protests as Greenpeace activists mark two months in detention

Russia grants bail to first Greenpeace activist

WHITE OUT
Researchers warn against high emissions from oil palm expansion in Brazil

Typhoon wiped out third of Philippines' rice crop: UN

Chinese buyer snaps up vintage wine at French auction

Angry French farmers to 'blockade' Paris

WHITE OUT
Powerful quake strikes far south Atlantic: USGS

Six dead in Vietnam floods: officials

Sardinia flash floods leave nine dead

Rare downpours and floods hit Saudi capital

WHITE OUT
Chinese candidate a Shanghai surprise in Mali polls

Nigerian troops claim nine Boko Haram members killed

Algeria only NAfrica state to block rights visits: HRW

Five killed in Sudan friendly-fire shooting: army

WHITE OUT
DNA of early hominid found to include 'mystery' early genes

China one-child law change small but crucial: experts

Dogs likely originated in Europe more than 18,000 years ago

China one-child law change small but crucial: experts




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal 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. 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. Privacy Statement