MIAMI – A scientist at the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science is leading an upcoming international research campaign to study a significant contributor to regional climate warming – smoke. The first-of-its-kind research experiment begins on June 1, 2016 from Ascension Island in the southeastern Atlantic Ocean. The experiment, called […]Read more...
MIAMI – A scientist at the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science is leading an upcoming international research campaign to study a significant contributor to regional climate warming – smoke. The first-of-its-kind research experiment begins on June 1, 2016 from Ascension Island in the southeastern Atlantic Ocean. The experiment, called LASIC (Layered Atlantic Smoke Interactions with Clouds), is part of a broader international scientific collaboration led by the Atmospheric Radiation Measurement (ARM) Climate Research Facility deployment. The broad collaboration is detailed in a new article in the July Bulletin of the American Meteorological Society.
Southern Africa is the world’s largest emitter of smoke particles in the atmosphere, known as biomass-burning aerosols, from the burning of grasslands and other biomass. The project will help researchers better understand the effects of widespread biomass burning on Earth’s climate.
The study will investigate how smoke particles flowing far offshore from the African continent affect the remote and cloudy southeast Atlantic climate. Smoke, which absorbs sunlight, is a warming agent in the climate system when located above a bright surface, such as clouds. The smoke overlying the southeast Atlantic provides one of the largest aerosol-based warming of climate on the planet, since the region is also home to one of the largest low-cloud decks on the planet.
“Ascension Island is an ideal location since it is very remote and allows us to sample the smoke after it is well-aged, about which less is known,” said Paquita Zuidema, professor of atmospheric sciences at the UM Rosenstiel School and principal investigator of the research experiment. The long deployment time will allow us to characterize the marine low clouds both with and without the presence of smoke. This is ultimately valuable for understanding the Earth’s energy balance.”
By evaluating how the low clouds respond to the presence of sunlight-absorbing aerosols, scientists can better understand low cloud behavior, which is currently an uncertainty in model predictions of future climate, since no fundamental theory on low cloud processes is yet in place.
Low clouds dominate the atmosphere over the southeast Atlantic Ocean all year. Bright white cloud appears darker when viewed from above when smoke is present. The southeast Atlantic overall is brighter, not darker when smoke is present, suggesting that the clouds become thicker and more extensive when smoke is present.
Zuidema received a $365,050 seed grant from the U.S. Department of Energy to plan the study. And a $440,225 grant from NASA which further supports related aircraft investigations as part of the NASA Earth Venture Suborbital-2 ORACLES project.
NASA will complement the DOE surface-based measurements with airborne experiments during a month of each year in 2016-2018. This will allow researchers to take airborne samples of smoke particles as it ages, information that will improve satellite retrievals of this mixed smoke-cloud regime. The United Kingdom will also participate with its research aircraft, and French, Namibian, and South African scientists will collect and interpret aircraft and ground-based measurements closer to the Namibian coast.
The UM Rosenstiel School-led research team will study how smoke is transported through the atmosphere and across the Atlantic, how the aerosols change when transported, and the response of the low-lying clouds to the smoke. The information from the experiments will ultimately be used to improve global aerosol models and climate change forecasts.
The phrase, ‘Eat your vitamins,’ applies to marine animals just like humans. Many vitamins are elusive in the ocean environment. University of Washington researchers used new tools to measure and track B-12 vitamins in the ocean. Once believed to be manufactured only by marine bacteria, the new results show that a whole different class of […]Read more...
The phrase, ‘Eat your vitamins,’ applies to marine animals just like humans. Many vitamins are elusive in the ocean environment.
University of Washington researchers used new tools to measure and track B-12 vitamins in the ocean. Once believed to be manufactured only by marine bacteria, the new results show that a whole different class of organism, archaea, can supply this essential vitamin. The results were presented Feb. 24 at the Ocean Sciences meeting in Honolulu.
“The dominant paradigm has been bacteria are out there, making B-12, but it turns out that one of the most common marine bacteria doesn’t make it,” said Anitra Ingalls, a UW associate professor of oceanography.
All marine animals, some marine bacteria and some tiny marine algae, or phytoplankton, need B-12, but only some microbes can produce the large, complex molecule. So like human vegetarians on land, marine organisms may be scouring for food that can help stave off vitamin deficiency.
“If only certain bacteria can make B vitamins, that can make B-12 a controlling factor in the environment. Is it present or not?” said Katherine Heal, a UW oceanography graduate student. “Studying the marine microbiome can help us understand what microbial communities could be supported where, and how that affects things like the ocean’s capacity to absorb atmospheric CO2.”
The UW team is the first to show that marine archaea, a single-celled organism that evolved totally separate from bacteria and all other living things, are making B-12. Relatives of these tiny critters are known for unusual behavior like living inside hot springs and underwater volcanoes.
The Seattle team managed to grow a common type of open-ocean archaea in the lab, no mean feat, and show that it not only makes enough B-12 to support its own growth but can supply some to the environment.
“It’s hard to quantify their contribution,” Ingalls said. “This is a first glimpse at their potential to contribute to this pool of vitamins.”
The analysis was done at a new UW marine chemistry center that does detailed analysis of proteins and other carbon-based chemicals in the ocean. The researchers used high-tech tools, including liquid chromatography and mass spectrometry, to identify the tiny amount of vitamins among all the dissolved matter and salt in the seawater. The UW method is unique in that it is the only one that can distinguish among the four forms of B-12 vitamins.
Field experiments involved sampling seawater in Hood Canal, near Seattle, and in the Pacific Ocean hundreds of miles offshore. The results showed that B-12 was present in small amounts in all water samples. Concentrations were low enough in some places that vitamin deficiency among tiny marine algae, or phytoplankton, is likely.
“Having a very small amount doesn’t mean there’s a very small supply,” Ingalls said. “Low concentrations can indicate something that’s highly desirable to marine organisms.”
The next step, researchers said, is to connect different microbes’ activity with the production of B vitamins, to see which organisms are responsible where, and to look at how ocean vitamins affect the type and amount of phytoplankton growing in the water.
Recent sequencing of the genomes of marine microbes has revealed genetic pathways in bacteria and archaea for creating B vitamins, but just because the gene is there doesn’t mean it’s being used. Marine microbes often adapt their behavior depending on the environment. In the case of vitamins, some bacteria make more B-12 if a phytoplankton is nearby, supporting their eventual food source.
Making a B-12 vitamin, which has a metal core and complex surrounding structure, involves 30-some steps.
“People think that’s why many organisms have lost it from their genomes,” Heal said. “It’s just too expensive to make it, and it’s easier to get it from food.”
The UW team hopes to learn which microbes are producing B-12 vitamins where, to better understand how the base of the marine food web works, how it might alter in a changing environment, how oceans might help regulate atmospheric carbon dioxide, and where marine animals could go to get a well-balanced diet.
“The public really has a very strange relationship to microorganisms,” Ingalls said. “People know they cause disease, so they want to kill them. But they’re also the only reason that we – or whales, fish or coral reefs – are alive.”
Collaborators are David Stahl, E. Virginia Armbrust, Allan Devol, Wei Qin and Laura Carlson at the UW, James Moffett at the University of Southern California and Willow Coyote, an undergraduate from Evergreen State College who will also present a poster at the meeting.