Nav: Home

Arctic greening thaws permafrost, boosts runoff

October 17, 2018

LOS ALAMOS, N.M., Oct. 17, 2018--A new collaborative study has investigated Arctic shrub-snow interactions to obtain a better understanding of the far north's tundra and vast permafrost system. Incorporating extensive in situ observations, Los Alamos National Laboratory scientists tested their theories with a novel 3D computer model and confirmed that shrubs can lead to significant degradation of the permafrost layer that has remained frozen for tens of thousands of years. These interactions are driving increases in discharges of fresh water into rivers, lakes and oceans.

"The Arctic is actively greening, and shrubs are flourishing across the tundra. As insulating snow accumulates atop tall shrubs, it boosts significant ground warming," said Cathy Wilson, Los Alamos scientist on the project. "If the trend of increasing vegetation across the Arctic continues, we're likely to see a strong increase in permafrost degradation."

The team investigated interactions among shrubs, permafrost, and subsurface areas called taliks. Taliks are unfrozen ground near permafrost caused by a thermal or hydrological anomaly. Some tunnel-like taliks called "through taliks" extend over thick permafrost layers.

Results of the Los Alamos study published in Environmental Research Letters this week revealed that through taliks developed where snow was trapped, warmed the ground and created a pathway for water to flow through deep permafrost, significantly driving thawing and likely increasing water and dissolved carbon flow to rivers, lakes and the ocean. Computer simulations also demonstrated that the thawed active layer was abnormally deeper near these through taliks, and that increased shrub growth exacerbates these impacts. Notably, the team subtracted warming trends from the weather data used to drive simulations, thereby confirming that the shrub-snow interactions were causing degradation even in the absence of warming.

The Los Alamos team and collaborators from the Department of Energy (DOE) Office of Science's Next-Generation Ecosystem Experiments Arctic program, which funds this project, used a new Los Alamos-developed fine-scale model, the Advanced Terrestrial Simulator (ATS). It incorporates soil physics and captures permafrost dynamics. The team repeatedly tested results against experimental data from Alaska's Seward Peninsula.

"These simulations of through talik formation provide clues as to why we're seeing an increase in winter discharge in the Arctic," said Los Alamos postdoctoral research associate Elchin Jafarov, first author on the paper.

This model is the first to show how snow and vegetation interact to impact permafrost hydrology with through talik formation on a slope--prevalent across Alaskan terrain. The team, including collaborators from Oak Ridge National Laboratory and the University of Alaska, investigated how quickly through taliks developed at different permafrost depths, their impact on hydrology and how they interrupted and altered continuous permafrost.
About Los Alamos National Laboratory

Los Alamos National Laboratory, a multidisciplinary research institution engaged in strategic science on behalf of national security, is operated by Los Alamos National Security, LLC, a team composed of Bechtel National, the University of California, BWX Technologies, Inc. and URS Corporation for the Department of Energy's National Nuclear Security Administration.

Los Alamos enhances national security by ensuring the safety and reliability of the U.S. nuclear stockpile, developing technologies to reduce threats from weapons of mass destruction, and solving problems related to energy, environment, infrastructure, health and global security concerns.

DOE/Los Alamos National Laboratory

Related Permafrost Articles:

Monitoring changes in wetland extent can help predict the rate of climate change
Monitoring changes to the amount of wetlands in regions where permafrost is thawing should be at the forefront of efforts to predict future rates of climate change, new research shows.
Domes of frozen methane may be warning signs for new blow-outs
Several methane domes, some 500m wide, have been mapped on the Arctic Ocean floor.
High release of strong greenhouse gas nitrous oxide found from northern peatlands at permafrost thaw
A recent study led by researchers from the University of Eastern Finland reveals that permafrost thaw may greatly increase emissions of nitrous oxide (N2O) from northern permafrost peatlands.
Huge permafrost thaw can be limited by ambitious climate targets
New study suggests that nearly 4 million square kilometres of frozen soil -- an area larger than India -- could be lost for every additional degree of global warming experienced.
Climate-driven permafrost thaw
In bitter cold regions like northwestern Canada, permafrost has preserved relict ground-ice and vast glacial sedimentary stores in a quasi-stable state.
Berkeley Lab researchers at AGU: Impacts of climate change, subsurface energy, understanding drought and monitoring permafrost among many talks
Berkeley Lab scientists will present on a number of topics including climate modeling challenges, projects on Arctic permafrost, induced seismicity, cloud physics, Amazon forests, hydraulic fracturing, melting ice sheets, cool roofs, and more.
When permafrost melts, what happens to all that stored carbon?
Arctic permafrost contains large stores of organic carbon that have been locked in for thousands of years.
Permafrost loss changes Yukon River chemistry with global implications
New USGS-led research shows that permafrost loss due to a rapidly warming Alaska is leading to significant changes in the freshwater chemistry and hydrology of Alaska's Yukon River Basin with potential global climate implications.
New permafrost map shows regions vulnerable to thaw, carbon release
A new mapping project has identified regions worldwide that are most susceptible to dramatic permafrost thaw formations, known as thermokarst, and the resulting release of greenhouse gases.
Study measures methane release from Arctic permafrost
A University of Alaska Fairbanks-led research project has provided the first modern evidence of a landscape-level permafrost carbon feedback, in which thawing permafrost releases ancient carbon as climate-warming greenhouse gases.

Related Permafrost Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Do animals grieve? Do they have language or consciousness? For a long time, scientists resisted the urge to look for human qualities in animals. This hour, TED speakers explore how that is changing. Guests include biological anthropologist Barbara King, dolphin researcher Denise Herzing, primatologist Frans de Waal, and ecologist Carl Safina.
Now Playing: Science for the People

#SB2 2019 Science Birthday Minisode: Mary Golda Ross
Our second annual Science Birthday is here, and this year we celebrate the wonderful Mary Golda Ross, born 9 August 1908. She died in 2008 at age 99, but left a lasting mark on the science of rocketry and space exploration as an early woman in engineering, and one of the first Native Americans in engineering. Join Rachelle and Bethany for this very special birthday minisode celebrating Mary and her achievements. Thanks to our Patreons who make this show possible! Read more about Mary G. Ross: Interview with Mary Ross on Lash Publications International, by Laurel Sheppard Meet Mary Golda...