Posts tagged NCAR
CU scientists discover a new threat from air pollution
Aug 8th
tied to climate change and human health issues
An international research team led by the University of Colorado Boulder and the University of Helsinki has discovered a surprising new chemical compound in Earth’s atmosphere that reacts with sulfur dioxide to form sulfuric acid, which is known to have significant impacts on climate and health.
The new compound, a type of carbonyl oxide, is formed from the reaction of ozone with alkenes, which are a family of hydrocarbons with both natural and man-made sources, said Roy “Lee” Mauldin III, a research associate in CU-Boulder’s atmospheric and oceanic sciences department and lead study author. The study charts a previously unknown chemical pathway for the formation of sulfuric acid, which can result both in increased acid rain and cloud formation as well as negative respiratory effects on humans.
“We have discovered a new and important, atmospherically relevant oxidant,” said Mauldin. “Sulfuric acid plays an essential role in Earth’s atmosphere, from the ecological impacts of acid precipitation to the formation of new aerosol particles, which have significant climatic and health effects. Our findings demonstrate a newly observed connection between the biosphere and atmospheric chemistry.”
A paper on the subject is being published in the Aug. 9 issue of Nature.
Typically the formation of sulfuric acid in the atmosphere occurs via the reaction between the hydroxyl radical OH — which consists of a hydrogen atom and an oxygen atom with unpaired electrons that make it highly reactive — and sulfur dioxide, Mauldin said. The trigger for the reactions to produce sulfuric acid is sunlight, which acts as a “match” to ignite the chemical process, he said.
But Mauldin and his colleagues had suspicions that there were other processes at work when they began detecting sulfuric acid at night, particularly in forests in Finland — where much of the research took place — when the sun wasn’t present to catalyze the reaction. “There were a number of instances when we detected sulfuric acid and wondered where it was coming from,” he said.
In the laboratory, Mauldin and his colleagues combined ozone — which is ubiquitous in the atmosphere — with sulfur dioxide and various alkenes in a gas-analyzing instrument known as a mass spectrometer hooked up with a “flow tube” used to add gases. “Suddenly we saw huge amounts of sulfuric acid being formed,” he said.
Because the researchers wanted to be sure the hydroxyl radical OH was not reacting with the sulfur dioxide to make sulfuric acid, they added in an OH “scavenger” compound to remove any traces of it. Later, one of the research team members held up freshly broken tree branches to the flow tube, exposing hydrocarbons known as isoprene and alpha-pinene — types of alkenes commonly found in trees and which are responsible for the fresh pine tree scent.
“It was such a simple little test,” said Mauldin. “But the sulfuric acid levels went through the roof. It was something we knew that nobody had ever seen before.”
Mauldin said the new chemical pathway for sulfuric acid formation is of interest to climate change researchers because the vast majority of sulfur dioxide is produced by fossil fuel combustion at power plants. “With emissions of sulfur dioxide, the precursor of sulfuric acid, expected to rise globally in the future, this new pathway will affect the atmospheric sulfur cycle,” he said.
According to the U.S. Environmental Protection Agency, more than 90 percent of sulfur dioxide emissions are from fossil fuel combustion at power plants and other industrial facilities. Other sulfur sources include volcanoes and even ocean phytoplankton. It has long been known that when sulfur dioxide reacts with OH, it produces sulfuric acid that can form acid rain, shown to be harmful to terrestrial and aquatic life on Earth.
Airborne sulfuric acid particles — which form in a wide variety of sizes — play the main role in the formation of clouds, which can have a cooling effect on the atmosphere, he said. Smaller particles near the planet’s surface have been shown to cause respiratory problems in humans.
Mauldin said the newly discovered oxidant might help explain recent studies that have shown large parts of the southeastern United States might have cooled slightly over the past century. Particulates from sulfuric acid over the forests there may be forming more clouds than normal, cooling the region by reflecting sunlight back to space.
Most of the laboratory experiments for the study were conducted at the Leibniz-Institute for Tropospheric Research in Leipzig, Germany.
Co-authors on the study include Torsten Berndt and Frank Stratmann from the Leibniz-Institute for Tropospheric Research; Mikko Sipilä, Pauli Paasonen, Tuukka Petäjä, Theo Kurtén, Veli-Matti Kerminen and Markku Kulmula from the University of Helsinki in Finland; and Saewung Kim from the National Center for Atmospheric Research in Boulder. Mauldin also is affiliated with NCAR and the University of Helsinki.
The study was funded by the European Commission Sixth Framework program, the Academy of Finland, The Finnish Center of Excellence, the European Research Council, the Kone Foundation, the Väisälä Foundation, the Maj and Tor Nessling Foundation, the Otto Malm Foundation and the U.S. National Science Foundation.
Boulder Fire Outbreak from lightning: Evacuations Flagstaff
Jun 26th
June 26, 4:45 p.m. – Pre-evacuation notices go to city residents
Pre-evacuation notices went out to 931 City of Boulder phone numbers. The area that received calls is bordered by Dartmouth on the north, Broadway on the east, all the way to the south edge of town. People should be ready to evacuate quickly. A Type 1 Federal Incident team is on its way.
June 26 – 4:19 p.m. – All Open Space properties are closed from Eldo. Springs to Boulder Canyon
All open space and recreational areas from Eldorado Springs to Boulder Canyon are closed until further notice.
June 26 – 4 p.m.
NCAR is voluntarily evacuating.
Media briefing at 4:30 p.m. at Criminal Justice Center at 6th and Canyon.
All Pets Animal Hospital is taking small animals. 303-499-5335. 5290 Manhattan Circle.
Fire is estimated to be 200-300 acres.
June 26 – 3:45 p.m. Road Closures – Bison Drive, Flagstaff Rd.
Road closures:
Bison Drive from 1000 block West
Flagstaff Rd. from Baseline & 6th Ave
Hard closures. No public access allowed. Residents are urged to take vital records and proof of residency when they leave.
June 26 – 3:28 p.m. – Flagstaff Fire evacuations ordered
Sheriff’s Command has issued evacuation orders for approximately 26 households in the area of Bison Drive and Pine Needle Notch subdivision. An evacuation point is being established at New Vista High School at 700 20th Street near Broadway and Baseline. Red Cross is on its way. Residents are advised to take vital records, proof of residency and all pets with them.
Follow #FlagstaffFire on Twitter
June 25 3:18 p.m. – Flagstaff Road is restricted to fire response
Flagstaff Rd. is being used for transport of firefighting equipment. Public access will be restricted or closed along this road until further notice.
June 26 – 3:01 p.m. Bison Fire
A helicopter and heavy air tanker are working on the Bison Fire which is estimated at 6 acres and growing. Smoke can be seen from the city of Boulder and surrounding areas. Rocky Mountain Fire is in charge of the fire.
Fire in Boulder County – June 26 – 2:51 p.m.
There is a fire burning near Bison Drive east of Walker Ranch in the foothills of southern Boulder County. A heavy air tanker is en route and 39 pre-evacuation notices have been sent to residents on Bison Drive and in the Pine Needle Notch subdivision.
Body found, search ends, sheriff won't confirm ID
Jun 24th
The body of missing CU student Nicholas Valore was presumably found in the Flatirons west of NCAR Friday at the base of a steep, rocky ridge. He had been missing since Sunday when he told friends he was going hiking. Fellow classmates alerted authorities that he had not returned by Thursday, His car was subsequently found in the NCAR parking lot. His hiking gear was not in the car.