(Press-News.org) This news release is available in German.
In their role as condensation nuclei, aerosol particles are an important trigger for the formation of clouds. As humidity accumulates on the particles droplets are formed, which later develop into clouds. Within the clouds, however, the chemical composition of these aerosol particles changes.
In order to find out exactly what happens within the clouds, Eliza Harris and Bärbel Sinha from the Max Planck Institute for Chemistry, together with other scientists form Mainz and further research institutes, investigated different air parcels. The special feature of their experiments was that they investigated a cloud which formed on top of a mountain. The scientists could therefore trace how the aerosol particles changed while the cloud was forming.
Eliza Harris' main focus was the analysis of sulfur compounds. She investigated their composition in air samples which were collected at different times: Before the parcels entered the cloud, while they were in the cloud, and after they left the cloud.
The sulfur compounds in the samples differed in the distribution of sulfur isotopes. Isotopes are atoms of the same elements differing in the number of neutrons in the core and thus can be differentiated with the help of a mass spectrometer. The NanoSIMS ion microprobe, a highly sensitive mass spectrometer, enabled Harris to look into the chemical processes. "The relative reaction rates of isotopes are like fingerprints, which tell us how the sulfate was formed from the sulfur dioxide", Eliza Harris explains her method, which was part of her doctoral research in the group of Peter Hoppe at the Max Planck Institute for Chemistry.
Harris' measurements showed that sulfate in clouds forms mostly through the oxidation of sulfur dioxide (SO2) by oxygen (O2). This reaction is catalysed by so-called transition metal ions (TMI) like iron, manganese, titanium or chromium. In addition, sulfate production mostly occurred in cloud droplets which formed on large mineral dust particles, the most important source of transition metal ions. Much less often the trail led to the oxidation of SO2 by hydrogen peroxide (H2O2) and ozone (O3). "As my colleagues and I compared the basic assumptions of climate models with my results we were very surprised, because only one of twelve models considers the role of transition metal ions in the formation of sulfate", says the scientist, who is now working at the Massachusetts Institute of Technology (MIT) in the USA. Instead, most of the models used the alternative pathways of sulfur dioxide oxidation by hydrogen peroxide (H2O2), ozone (O3) and the hydroxyl radical (OH).
Sulfate produced catalytically through transition metal ions are formed on relatively large mineral dust particles, making them bigger than those formed through the reaction with hydrogen peroxide. Due to their size, they fall from the air at a faster rate – by force of gravity. The time frame for climate cooling by sulfate particles could therefore be shorter than has been believed.
Eliza Harris assumes that the models have overestimated the climate cooling effect of sulfate aerosols. So far it is not quantifiable to what degree Harris' discovery will impact climate prognoses. However, future models should consider the TMI catalysis reaction as an important pathway for the oxidation of sulfur dioxide, says the scientist. She thinks that the impact on climate models of European regions might probably be low, as mineral dust concentrations in the air are small and sulfur dioxide (SO2) emissions are declining. "In India and China, however, where sulfur dioxide emissions are expected to rise in the near future, combined with significantly higher concentrations of mineral dust in the air, the effect could be stronger", assumes Harris. Future studies will show.
INFORMATION:
The study, which has been published in the journal Science (Vol…), was conducted in collaboration with the following institutes: the Max Planck Institute for Chemistry in Mainz, the Leibniz Institute for Tropospheric Research in Leipzig, the Department of Atmospheric Science at Colorado State University, the Earth System Science Research Centre at the Institute of Geosciences at the University of Mainz, and the Institute of Atmospheric Physics at the University of Mainz.
Eliza Harris was recently awarded the Dieter Rampacher Prize as youngest doctoral candidate of the Max Planck Society in 2012.
Sulfate aerosols cool climate less than assumed
Life span of cloud-forming sulfate particles in the air is shorter than assumed due to a sulfur dioxide oxidation pathway which has been neglected in climate models so far
2013-05-14
ELSE PRESS RELEASES FROM THIS DATE:
But what does it do?
2013-05-14
Although we know the tool's general purpose, it can sometimes be difficult to tell if a specific pair of precision tweezers belongs to a surgeon or a master jeweller. It is now easier to solve similar conundrums about a type of protein that allows cells to react to their environment, thanks to scientists at the European Molecular Biology Laboratory (EMBL). Published today in Science Signaling, their work offers a valuable resource for other researchers.
Whether in your eye being hit by light, in your blood fighting off disease, or elsewhere throughout your body, cells ...
Cooling ocean temperature could buy more time for coral reefs
2013-05-14
Limiting the amount of warming experienced by the world's oceans in the future could buy some time for tropical coral reefs, say researchers from the University of Bristol.
The study, published by the journal Geophysical Research Letters, used computer models to investigate how shallow-water tropical coral reef habitats may respond to climate change over the coming decades.
Elena Couce and colleagues found that restricting greenhouse warming to three watts per square metre (equivalent to just 50-100 parts per million carbon dioxide, or approximately half again the increase ...
New software spots, isolates cyber-attacks to protect networked control systems
2013-05-14
Researchers from North Carolina State University have developed a software algorithm that detects and isolates cyber-attacks on networked control systems – which are used to coordinate transportation, power and other infrastructure across the United States.
Networked control systems are essentially pathways that connect and coordinate activities between computers and physical devices. For example, the systems that connect temperature sensors, heating systems and user controls in modern buildings are networked control systems.
But, on a much larger scale, these systems ...
When green means danger: A stunning new species of palm-pitviper from Honduras
2013-05-14
A new species of green palm-pitviper of the genus Bothriechis is described from a seriously threatened cloud forest reserve in northern Honduras. Because of similarity in color pattern and scalation, the new species (Bothriechis guifarroi) was previously confused with other Honduran palm pitvipers. Genetic analysis revealed that the closest relatives of the new species are actually found over 600 km to the south, in the mountains of Costa Rica. The study was published in the open access journal Zookeys.
The gorgeous new species was discovered by scientists during two ...
CWRU researcher searches for global views of nurses' end-of-life care for patients
2013-05-14
Nurses will use extreme measures to save their patients and parents; but if they were dying, they prefer less aggressive ones for themselves, according to results from an international survey on nurses' end-of-life preferences.
The April issue of the International Nursing Review reported the findings about the end-of-life preferences of 1,089 nurses in the first multinational and cross-cultural view of nurses' end-of-life care choices.
Two factors influenced the care of people dying: lack of knowledge about the patient's wishes and the call of duty, according to Joyce ...
Bacterium counteracts 'coffee ring effect'
2013-05-14
Ever notice how a dried coffee stain has a thicker outer rim, while the middle of the stain remains almost unsoiled? This 'coffee ring effect' also occurs in other materials. Researchers from the Departments of Chemical Engineering and Chemistry at KU Leuven have now discovered how to counteract coffee rings with 'surfactants', i.e. soap. The key to the discovery was not a kitchen towel, but a bacterium that counteracts the coffee ring effect at the microscopic level. The findings were published in a recent edition of the leading journal Nature Communications.
When a ...
Crop rotation with nematode-resistant wheat can protect tomatoes
2013-05-14
In a study published online today in Crop Science, scientists describe a nematode-resistant wheat. But while the wheat carries the resistance to the pest, the benefits are actually seen in the crop that is grown after it.
Root-knot nematodes cause crop losses around the world, and they can be difficult to control. In order to reproduce, nematodes need to infect a living plant root. Once they are present in soil, they can survive winter in a fallow field and infect plants during the next growing season. Trap crops – unsuitable hosts that "trick" the nematodes into starting ...
Cutting-edge bacteria research leads to more effective treatment of complex infections
2013-05-14
Bacteria are life forms, which, like all other life forms, struggle for the best living conditions for themselves. Therefore they will try to avoid getting attacked by the human immune system, and therefore they have developed various ways to protect themselves from the human immune system. When safe from the immune system, they can focus on breeding and multiplying, and if they become numerous enough, the human body will experience their presence as an infection. Some bacteria are relatively harmless, while others are fatal. The bacteria avoid being attacked by the human ...
Widespread but neglected disease a health threat in Africa, Virginia Tech researchers say
2013-05-14
The newest public health threat in developing countries may not be a cinematic-quality emerging disease but actually a disease from animals that was identified more than 100 years ago.
Virginia Tech researchers have identified leptospirosis as a significant health threat in Botswana. The world's most common disease transmitted to humans by animals, according to the World Health Organization, leptospirosis is a two-phase disease that begins with flu-like symptoms but can cause meningitis, liver damage, pulmonary hemorrhage, renal failure, and even death if untreated.
"The ...
Relationship troubles? Some sad music might help you feel better
2013-05-14
Consumers experiencing relationship problems are more likely to prefer aesthetic experiences that reflect their negative mood, according to a new study in the Journal of Consumer Research.
"Emotional experiences of aesthetic products are important to our happiness and well-being. Music, movies, paintings, or novels that are compatible with our current mood and feelings, akin to an empathic friend, are more appreciated when we experience broken or failing relationships," write authors Chan Jean Lee (KAIST Business School), Eduardo B. Andrade (FGV School of Administration), ...
LAST 30 PRESS RELEASES:
Program takes aim at drinking, unsafe sex, and sexual assault on college campuses
Inability to pay for healthcare reaches record high in U.S.
Science ‘storytelling’ urgently needed amid climate and biodiversity crisis
KAIST Develops Retinal Therapy to Restore Lost Vision
Adipocyte-hepatocyte signaling mechanism uncovered in endoplasmic reticulum stress response
Mammals were adapting from life in the trees to living on the ground before dinosaur-killing asteroid
Low LDL cholesterol levels linked to reduced risk of dementia
Thickening of the eye’s retina associated with greater risk and severity of postoperative delirium in older patients
Almost one in ten people surveyed report having been harmed by the NHS in the last three years
Enhancing light control with complex frequency excitations
New research finds novel drug target for acute myeloid leukemia, bringing hope for cancer patients
New insight into factors associated with a common disease among dogs and humans
Illuminating single atoms for sustainable propylene production
New study finds Rocky Mountain snow contamination
Study examines lactation in critically ill patients
UVA Engineering Dean Jennifer West earns AIMBE’s 2025 Pierre Galletti Award
Doubling down on metasurfaces
New Cedars-Sinai study shows how specialized diet can improve gut disorders
Making moves and hitting the breaks: Owl journeys surprise researchers in western Montana
PKU Scientists simulate the origin and evolution of the North Atlantic Oscillation
ICRAFT breakthrough: Unlocking A20’s dual role in cancer immunotherapy
How VR technology is changing the game for Alzheimer’s disease
A borrowed bacterial gene allowed some marine diatoms to live on a seaweed diet
Balance between two competing nerve proteins deters symptoms of autism in mice
Use of antifungals in agriculture may increase resistance in an infectious yeast
Awareness grows of cancer risk from alcohol consumption, survey finds
The experts that can outsmart optical illusions
Pregnancy may reduce long COVID risk
Scientists uncover novel immune mechanism in wheat tandem kinase
Three University of Virginia Engineering faculty elected as AAAS Fellows
[Press-News.org] Sulfate aerosols cool climate less than assumedLife span of cloud-forming sulfate particles in the air is shorter than assumed due to a sulfur dioxide oxidation pathway which has been neglected in climate models so far