Microbes fuelled by wind-blown mineral dust melt the Greenland ice sheet
2021-01-25
(Press-News.org) Scientists have identified a key nutrient source used by algae living on melting ice surfaces linked to rising sea levels.
The Greenland ice sheet - the second largest ice body in the world after the Antarctic ice sheet - covers almost 80% of the surface of Greenland. Over the last 25 years, surface melting and water runoff from the ice sheet has increased by about 40%.
The international research team, led by the University of Leeds, analysed samples from the southwestern margin on Greenland's 1.7 million km² ice sheet over two years.
They discovered that phosphorus containing minerals may be driving ever-larger algal blooms on the Greenland Ice Sheet. As the algal blooms grow they darken the ice surface, decreasing albedo - the ability to reflect sunlight. The blooms cause increased melting thus contributing to higher sea levels. In particular, a band of low-albedo ice, known as the Dark Zone, has developed along the western margin of the massive ice sheet.
The research, published in Nature Communications, investigates the origin and impact of this phosphorus on algal blooms the Greenland Ice Sheet, improving understanding of how glacier ice algal blooms will contribute to future ice sheet melting.
By examining the surface dust, the scientists were able to demonstrate how phosphorus is used as a key nutrient to help the algae grow, identifying the phosphorus-bearing mineral hydroxylapatite as the source of fuel for the blooms in the Dark Zone. The hydroxylapatite was blown onto the ice from local rock outcrops.
Dr Jenine McCutcheon led the study while at Leeds' School of Earth and Environment, and is now an Assistant Professor at the University of Waterloo, Canada.
She said: "The photosynthesis rate of the ice algae improved significantly when we provided them with a source of phosphorus.
"Our mineralogy results revealed that the phosphorus used by ice algae may be coming from the hydroxylapatite we identified in the mineral dust.
"It's important to understand the controls on algal growth because of their role in ice sheet darkening.
"Although algal blooms can cover up to 78% of the bare ice surfaces in the Dark Zone, their abundance and size can vary greatly over time."
Dr McCutcheon added: "From one season to the next, algal blooms may change and vary in intensity, making them difficult to model year-to-year".
Associate Professor, Jim McQuaid at Leeds' School of Earth and Environment, is a co-author of the paper.
He said: "Mineral dust can be transported thousands of miles by wind, but the dust we examined was from local sources. As dryland areas in northerly latitudes become even drier under climate change, we can expect to see more dust transported and deposited on the Greenland Ice Sheet, further fuelling algal blooms.
"As atmospheric scientist, it's exciting to see how wind-blown mineral dust is linked to algal bloom development and impacts ice sheet melting."
Previous studies have shown that since 2000, the melt season in the Dark Zone has progressively started earlier and lasted longer, resulting in reduced ability for the ice sheet to reflect solar radiation.
Dr McCutcheon said: "The findings of this study will improve how we predict where algal blooms will happen in the future, and help us gain a better understanding of their role in ice sheet albedo reduction and enhanced melting."
Professor Liane G. Benning is the Leeds Principal Investigator of the £4 million Natural Environment Research Council project Black and Bloom, and is now at the German Research Centre for Geosciences in Potsdam, Germany.
She said: "The glacier ice algae bio-mine the phosphorus from the minerals fuelling the blooms that cover larger and larger areas each year, leading to more melting and faster rising sea levels.
"As current icesheet and climate models do not include this phenomena, this research will advance these models and give us a greater understanding of the annual lifecycle of algal blooms."
INFORMATION:
[Attachments] See images for this press release:
ELSE PRESS RELEASES FROM THIS DATE:
2021-01-25
EAST LANSING, Mich. - An international team of researchers led by Michigan State University's Morteza Mahmoudi has developed a new method to better understand how nanomedicines -- emerging diagnostics and therapies that are very small yet very intricate -- interact with patients' biomolecules.
Medicines based on nanoscopic particles have the promise to be more effective than current therapies while reducing side effects. But subtle complexities have confined most of these particles to research labs and out of clinical use, said Mahmoudi, an assistant professor in the Department of Radiology and the Precision Health Program.
"There's been a considerable investment of taxpayer money in cancer nanomedicine research, but that research hasn't successfully translated ...
2021-01-25
Even before public announcements of the first cases of COVID-19 in Europe were made, at the end of January 2020, signals that something strange was happening were already circulating on social media. A new study of researchers at IMT School for Advanced Studies Lucca, published in END ...
2021-01-25
The rate at which ice is disappearing across the planet is speeding up, according to new research.
And the findings also reveal that the Earth lost 28 trillion tonnes of ice between 1994 and 2017 - equivalent to a sheet of ice 100 metres thick covering the whole of the UK.
The figures have been published today (Monday, 25 January) by a research team which is the first to carry out a survey of global ice loss using satellite data.
The team, led by the University of Leeds, found that the rate of ice loss from the Earth has increased markedly within the past three decades, from 0.8 trillion tons per year in the 1990s to 1.3 trillion tons per year by 2017.
Ice melt across the globe ...
2021-01-25
Female childhood cancer survivors face a lower likelihood of becoming pregnant than women in the general population, but once pregnant, they are not more likely to undergo an abortion. The findings come from a new study published early online in CANCER, a peer-reviewed journal of the American Cancer Society.
Cancer survivors might be reluctant to start a family due to concerns for their children's health as well as the potential recurrence of their own cancer. This could lead to a greater likelihood of induced abortions in female survivors who become pregnant.
To examine whether pregnancies of childhood cancer survivors are more likely to end with ...
2021-01-25
AUGUSTA, Ga. (January 25, 2021) - Immediately after a traumatic brain injury and as long as one year later, there are increased levels of immune cells called ILCs in the brain promoting inflammation, which can worsen brain damage, scientists report.
They also report for the first time that the cell energy sensor AMPK is a brake that can stop what becomes a chronic state of destructive inflammation driven by these ILCs, or innate lymphoid cells.
"We think ILCs are kind of a master regulator of all that inflammation happening within the brain," says Dr. Krishnan Dhandapani, neuroscientist in the Department of Neurosurgery at the Medical College of Georgia at Augusta University. "It's like the ...
2021-01-25
These results were published in the prestigious journal ChemSusChem and thanks to the remarkable reviews, the paper was ranked among the top five percent publications in the field, thus earning a Very Important Paper (VIP) status. Furthermore, the editorial board featured this study on its cover.
Plastic pollution has become one of the most complex environmental issues, especially in the context of increasing production and demand for plastic materials. While innovations in polymer chemistry have radically changed our lives in the mid-20th century, the outstanding properties of plastics such as durability, chemical stability, strength and many other pose a serious problem ...
2021-01-25
PULLMAN, Wash. - Man's best friend might actually belong to a woman.
In a cross-cultural analysis, Washington State University researchers found several factors may have played a role in building the mutually beneficial relationship between humans and dogs, including temperature, hunting and surprisingly - gender.
"We found that dogs' relationships with women might have had a greater impact on the dog-human bond than relationships with men," said Jaime Chambers, a WSU anthropology Ph.D. student and first author on the paper published in the Journal of Ethnobiology. "Humans were more likely to regard dogs as a type of person if the dogs had a special ...
2021-01-25
Arctic sea ice is rapidly diminishing due to global warming, and scientists have found that sea ice dynamics have a big impact on circulation and precipitation patterns in Arctic Alaska, which lies at a climatological crossroads between the Arctic and North Pacific Oceans. Recent studies--most of which focus on current trends in the region and on what will happen in the future--have shown that circulation patterns in the Arctic and North Pacific Oceans influence one another.
Doctoral candidate Ellie Broadman of Northern Arizona University's School of Earth and Sustainability wanted to learn about this relationship on a longer timescale, so she developed and led a ...
2021-01-25
A group of scientists is calling on governments to consider the continued use of strict control measures as the only way to reduce the evolution and spread of new COVID-19 variants.
The experts in evolution, virology, infectious disease and genomics - at the University of East Anglia (UEA), Earlham Institute and University of Minnesota - warn that while governments are negotiating a "precarious balance" between saving the economy and preventing COVID-19 fatalities, stronger action now is the best way to mitigate against more serious outcomes from such virulent strains later.
While COVID-19 vaccine deployment is now underway, a threat to vaccine effectiveness comes from other emerging strains, both existing - such as the UK, South Africa and Brazil variants ...
2021-01-25
New estimates reveal extent of the health burden of armed conflict--affecting at least 630 million women and children worldwide in 2017, and contributing to more than 10 million deaths among children under 5 years of age over 20 years.
Changing nature of war is a growing threat to humanitarian access and the provision of essential health services for women and children, but responses in countries like Syria, Pakistan, and Colombia may provide context-specific innovative ways forward.
Armed conflicts are becoming increasingly complex and protracted and a growing threat to humanitarian access and the delivery of essential health services, affecting at least 630 million women and ...
LAST 30 PRESS RELEASES:
[Press-News.org] Microbes fuelled by wind-blown mineral dust melt the Greenland ice sheet
