Scientists from the University of Geneva discovered that studying water masses enables them to analyze organic aerosols, which influence cloud formation
Aerosols are collections of fine particles, either biological or of other types, in suspension in a gaseous medium. They play a major role in cloud formation and therefore have a strong impact on climate models. They are however extremely hard to study due to the small size and immense variety of their constituent particles.
Representation of the temperatures on the surface of the Atlantic Ocean near the north-american coast. In blue, the colder bodies of water where biological activity is more important. In yellow, warmer bodies of water where biological activity is weaker. Along the PlanetSolar itinerary, the colored dots represent the concentration of organic aerosols, from blue (light concentration) to red (strong concentration).
But researchers from the University of Geneva (UNIGE), Switzerland, members of the PlanetSolar Deepwater expedition, have now succeeded in linking the composition of marine biological aerosols -- and therefore their influence on the climate -- to that of bodies of water under them within the Atlantic Ocean, thereby paving the way to an indirect study of these aerosols through water analysis. This study, which has been published in Scientific Reports, will contribute to making climate models more accurate.
Aerosols are fine particles in suspension in the air. Over the oceans, some contain organic or biological ingredients (bacteria, degradation products of microscopic algae) which come from sea spray, others are transported in the air (mineral dust, smoke).
They serve as seeds for forming clouds and also reflect light. Their role is extremely important for modelling clouds, and therefore for the climate in general. But due to the small size of the particles and their large quantity, it's difficult to accurately study them. So researchers at the University of Geneva (UNIGE) asked themselves if it would be possible to characterize biological aerosols through the composition of the water whence they come.
"To answer this question, we needed two tools," explains Jérôme Kasparian, Professor in the Department of Applied Physics at the UNIGE Science Faculty. "The first is a detector of fluorescence which we designed, called Biobox, and which enables us to analyse aerosol particles one by one.
The spectrum gives us information on their composition and distinguishes the organic particles, which are fluorescent, from the other particles. Then we needed PlanetSolar." Indeed this research could only be undertaken over a long time period of time without any disturbances of water and air. Only PlanetSolar, a solar boat that navigated remains at sea for three months and produces no emissions, could make it possible.
During the expedition, scientists carried out analysis of the salinity, temperature, dissolved oxygen and the microalgae contained in the various bodies of water in the Atlantic, and then compared this data with that obtained by the Biobox. "And we found that they matched!" exclaims Jérôme Kasparian. The physicists discovered that biological aerosols are related to the temperature and salinity of the sea.
According to previous criteria, water creates large bodies that don't inter-mix, which allows them to be differentiated. Thus, when the characteristics of a water mass were favourable for reproduction of microalgae, researchers noticed that after a certain amount of time, the aerosols detected above this same water mass contained more biological particles. The biological fraction of aerosols is therefore linked to the history of biological activity of bodies of water close to the surface.
"Provided that this is also valid in oceans and seas other than the Atlantic, our research location, our results would allow us to estimate biological aerosols by directly studying the bodies of water, which would simplify aerosol caracterization and make climate models more accurate," adds Kasparian. Difficult to study directly, aerosols are now being studied via the sea, which, unlike aerosols, can easily be analysed by satellites.
Jérôme Kasparian | EurekAlert!
Filling the gap: High-latitude volcanic eruptions also have global impact
20.11.2017 | Institute of Atmospheric Physics, Chinese Academy of Sciences
Antarctic landscape insights keep ice loss forecasts on the radar
20.11.2017 | University of Edinburgh
The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.
Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....
The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.
Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
21.11.2017 | Physics and Astronomy
21.11.2017 | Physics and Astronomy
21.11.2017 | Life Sciences