University of Alaska Southeast Associate Professor Eran Hood is the second author of the study, to be published in the international journal Nature Geoscience in March 2012 and published on-line this week. "When we look at the marine food webs today, we may be seeing a picture that is significantly different from what existed before the late-18th century," said first author Aron Stubbins of the Skidaway Institute of Oceanography.
Hood led the fieldwork on glaciers in Juneau, Alaska where visiting scholar-scientists from throughout the Lower 48 sampled snow, ice melt, and glacier runoff. The organic carbon from these water and snow samples was isolated and carbon dated. “We analyzed its molecular chemical structure,” said Hood. “The carbon fingerprint we found indicated aerosols derived from the combustion of fossil fuels are an important source of organic matter on glacier surfaces and also in glacier outflow streams.”
The scientists said glaciers like the Mendenhall offer ideal evidence of soot from carbon emissions. This "black carbon," darkens glacier surfaces and increases their absorption of light and heat. The carbon can also be exported to ecosystems downstream from glaciers where it can be metabolized and become part of the food web.
"These findings show that glaciers like Mendenhall can provide us with novel information about how humans are altering the composition of the atmosphere as a result of burning biomass and fossil fuels" said Hood. "The fact that we see this human-derived carbon signature in Alaskan glaciers also indicates that we still do not fully appreciate the post-industrial changes in the earth's surface biogeochemical cycles."
Glaciers and ice sheets together represent the second largest reservoir of water on the planet, and glacier ecosystems cover ten percent of the Earth, yet the carbon dynamics underpinning those ecosystems remain poorly understood. "Improving our understanding of glacier biogeochemistry is of great urgency, as glacier environments are among the most sensitive to climate change and the effects of industrial pollution,” emphasized Rob Spencer of the Woods Hole Research Center, another author on the study.
A warming climate will increase the outflow of the glaciers and the accompanying input of dissolved organic material into the coastal ocean. This will be most keenly felt in glacial coastal regions with the highest levels of ice loss including the Gulf of Alaska, Greenland and Patagonia.
The title of the study is “Anthropogenic aerosols as a source of ancient dissolved organic matter in glaciers.” In addition to Stubbins and Spencer, Hood’s fellow collaborators on the project were Andrew Vermilyea from the University of Alaska Southeast; Peter Raymond and David Butman from Yale University; George Aiken, Robert Striegl and Paul Schuster from the U.S. Geological Survey; Rachel Sleighter, Hussain Abdulla and Patrick Hatcher from Old Dominion University; Peter Hernes from the University of California-Davis; Durelle Scott from Virginia Polytechnic Institute and State University.
More information and a slideshow of photographs by Hood can be found in the U.S. National Science Foundation on-line article, “Scientists Unlock Record of Ecosystem Changes Frozen in World's Glaciers”: http://www.nsf.gov/news/news_summ.jsp?cntn_id=123154Eran Hood
Eran Hood | Newswise Science News
GPM sees deadly tornadic storms moving through US Southeast
01.12.2016 | NASA/Goddard Space Flight Center
Cyclic change within magma reservoirs significantly affects the explosivity of volcanic eruptions
30.11.2016 | Johannes Gutenberg-Universität Mainz
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water
In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...
The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.
Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
02.12.2016 | Medical Engineering
02.12.2016 | Agricultural and Forestry Science
02.12.2016 | Physics and Astronomy