Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists make first direct observations of biological particles in high-altitude clouds

19.05.2009
Airborne dust and microbial matter appear to play large role in ice formation in clouds

A team of atmospheric chemists has moved closer to what's considered the "holy grail" of climate change science: the first-ever direct detections of biological particles within ice clouds.

The team, led by Kimberly Prather and Kerri Pratt of the University of California at San Diego, Scripps Institution of Oceanography, sampled water droplet and ice crystal residues at high speeds while flying through clouds in the skies over Wyoming.

Analysis of the ice crystals revealed that the particles that started their growth were made up almost entirely of either dust or biological material such as bacteria, fungal spores and plant material.

While it has long been known that microorganisms become airborne and travel great distances, this study is the first to yield direct data on how they work to influence cloud formation.

Results of the Ice in Clouds Experiment - Layer Clouds (ICE-L), funded by the National Science Foundation (NSF), appear May 17 in the advance online edition of the journal Nature Geoscience.

"If we understand the sources of the particles that nucleate clouds, and their relative abundance, we can determine their impact on climate," said Pratt, lead author of the paper.

The effects of tiny airborne particles called aerosols on cloud formation have been some of the most difficult aspects of weather and climate for scientists to understand.

In climate change science, which derives many of its projections from computer simulations of climate phenomena, the interactions between aerosols and clouds represent what scientists consider the greatest uncertainty in modeling predictions for the future.

"By sampling clouds in real time from an aircraft, these investigators were able to get information about ice particles in clouds at an unprecedented level of detail," said Anne-Marie Schmoltner of NSF's Division of Atmospheric Sciences, which funded the research.

"By determining the chemical composition of the very cores of individual ice particles, they discovered that both mineral dust and, surprisingly, biological particles play a major role in the formation of clouds."

Aerosols, ranging from dust, soot, and sea salt to organic materials, some of which travel thousands of miles, form the skeletons of clouds.

Around these nuclei, water and ice in the atmosphere condense and grow, leading to precipitation. Scientists are trying to understand how the nuclei form, as clouds play a critical role by both cooling the atmosphere and affecting regional precipitation processes.

The ICE-L team mounted a mass spectrometer onto a C-130 aircraft operated by the National Center for Atmospheric Research (NCAR) in Boulder, Colo., and made a series of flights through a type of cloud known as a wave cloud.

The researchers performed in-situ measurements of cloud ice crystal residues and found that half were mineral dust and about a third were made up of inorganic ions mixed with nitrogen, phosphorus and carbon--the signature elements of biological matter.

The second-by-second speed of the analysis allowed the researchers to make distinctions between water droplets and ice particles. Ice nuclei are rarer than droplet nuclei.

The team demonstrated that both dust and biological material indeed form the nuclei of these ice particles, something that previously could only be simulated in laboratory experiments.

"This has really been kind of a holy grail measurement for us," said Prather.

"Understanding which particles form ice nuclei, and which have extremely low concentrations and are inherently difficult to measure, means you can begin to understand processes that result in precipitation. Any new piece of information you can get is critical."

The findings suggest that the biological particles that get swept up in dust storms help to induce the formation of cloud ice, and that their region of origin makes a difference. Evidence is increasingly suggesting that dust transported from Asia could be influencing precipitation in North America, for example.

Researchers hope to use the ICE-L data to design future studies timed to events when such particles may play a bigger role in triggering rain or snowfall.

The research was also supported by NCAR.

Paper co-authors include Paul DeMott and Anthony Prenni from Colorado State University, Jeffrey French and Zhien Wang of the University of Wyoming, Douglas Westphal of the Naval Research Laboratory in Monterey, Calif., Andrew Heymsfield of the National Center for Atmospheric Research, and Cynthia Twohy of Oregon State University.

Cheryl Dybas | EurekAlert!
Further information:
http://www.nsf.gov

More articles from Earth Sciences:

nachricht By saving cost and energy, the lighting revolution may increase light pollution
23.11.2017 | Helmholtz-Zentrum Potsdam - Deutsches GeoForschungsZentrum GFZ

nachricht Frictional Heat Powers Hydrothermal Activity on Enceladus
23.11.2017 | Universität Heidelberg

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Frictional Heat Powers Hydrothermal Activity on Enceladus

Computer simulation shows how the icy moon heats water in a porous rock core

Heat from the friction of rocks caused by tidal forces could be the “engine” for the hydrothermal activity on Saturn's moon Enceladus. This presupposes that...

Im Focus: Nanoparticles help with malaria diagnosis – new rapid test in development

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....

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

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...

Im Focus: Visual intelligence is not the same as IQ

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...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

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....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

Underwater acoustic localization of marine mammals and vehicles

23.11.2017 | Information Technology

Enhancing the quantum sensing capabilities of diamond

23.11.2017 | Physics and Astronomy

Meadows beat out shrubs when it comes to storing carbon

23.11.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>