Aerosols have impact on cloud composition, duration
All over the planet, every day, oceans send plumes of sea spray into the atmosphere. Beyond the poetry of crashing ocean waves, this salt- and carbon-rich spray also has a dramatic effect on cloud formation and duration.
In a new paper published this week in the journal Proceedings of the National Academy of Sciences, Colorado State University atmospheric scientist Paul DeMott finds that sea spray is a unique, underappreciated source of what are called ice nucleating particles. These microscopic bits make their way into clouds and initiate the formation of ice, affecting the clouds' composition.
"The presence of these particles is critically important for precipitation and the lifetime of clouds, and consequently, for their radiative properties," DeMott said.
Added Nick Anderson, program director in the National Science Foundation (NSF) Division of Atmospheric and Geospace Sciences, which funded the research: "The development of clouds and precipitation is a core issue for understanding weather and climate processes. By studying ice nuclei, which can be considered a building block for clouds, these researchers will help piece together the puzzle of how clouds and precipitation form, especially over remote oceanic regions."
Clouds cover 60 percent of the Earth's surface at any given time. With their ability to reflect solar energy and absorb terrestrial radiation, clouds have dramatic effects on climate.
That ability is greatly influenced by the number, size and type of droplets and ice particles they contain. These cloud particles come from aerosols -- particles suspended in air -- from land and ocean surfaces.
From desert dust to fossil fuels, aerosols that affect clouds are everywhere.
The study has confirmed that ice nucleating particles from oceans are distinct -- both in their abundance and ice-making properties -- from land-sourced particles. Hence, their influence on the liquid-to-ice phase structure of clouds, and the clouds' radiative characteristics, can differ over vast swaths of Earth.
The laboratory portion of the study was conducted with other researchers at the NSF-supported Center for Aerosol Impacts on Climate and the Environment (CAICE), at which DeMott is a senior scientist.
Based at the University of California-San Diego, CAICE has laboratory wave flumes that simulate how ocean waves send sea spray aerosols into the air.
Researchers can study the biological and chemical makeup of these particles, as well as the transformations they undergo, and use special instruments to see how they influence cloud formation. DeMott and colleagues compared these data to other measurements made over oceans.
The study offers one explanation for why global climate models have consistently underestimated reflected, short-wave solar radiation in regions dominated by oceans, particularly in the southern hemisphere.
"Our paper gives a clearer picture of the behavior of major classes of atmospheric aerosols in clouds," DeMott said.
Cheryl Dybas | EurekAlert!
From volcano's slope, NASA instrument looks sky high and to the future
27.04.2017 | NASA/Goddard Space Flight Center
Penn researchers quantify the changes that lightning inspires in rock
27.04.2017 | University of Pennsylvania
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
20.04.2017 | Event News
18.04.2017 | Event News
03.04.2017 | Event News
27.04.2017 | Life Sciences
27.04.2017 | Physics and Astronomy
27.04.2017 | Earth Sciences