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Holodeck? Using holography to better understand clouds

Date:
October 1, 2015
Source:
Michigan Technological University
Summary:
Researchers use a real life HOLODEC (yes, said like the Star Trek holodeck). The instrument creates a holographic model of water droplets in clouds. Check out the airborne laboratory the researchers fly with the National Center for Atmospheric Research and what the crew sees inside clouds.
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The HOLODEC instrument, or Holographic Detector for Clouds, enables researchers from Michigan Tech and the National Center for Atmospheric Research to recreate 3-D models of water droplets within clouds. The size of these droplets and how they mix with dry air affects cloud growth and the way they interact with light. Knowing more details at the droplet-scale could have an impact on regional and even global weather and climate models.
Credit: NCAR

As clouds change shape, mixing occurs, as drier air mingles with water-saturated air. New research led by Michigan Technological University analyzes this mixing with a holographic imaging instrument called HOLODEC and an airborne laboratory. The work was done in collaboration with the National Center for Atmospheric Research (NCAR), Max Planck Institute for Chemistry and Mainz University.

This new way of seeing clouds--and the way wet and dry air form sharp boundaries--is the focus of the team's study, published in Science this week. What the team found with these naturally created boundaries, formed by completely evaporating some water drops and leaving others unscathed, is called inhomogenous mixing. And it goes against base assumptions used in most computer models assume for cloud formations.

The findings will influence models that help predict weather and climate change.

Raymond Shaw, a professor of physics at Michigan Tech, looks at the smallest part of clouds: droplets. To understand groups of droplets, Shaw and the NCAR team flew airplanes through fluffy, cottonball cumulus clouds in Wyoming and Colorado. Aboard the plane, the team took detailed 3-D images with an instrument called the Holographic Detector for Clouds (HOLODEC--yes that's like Star Trek "holodeck"). These particular clouds were only made up of liquid water and the size of those drops is a key part of cloud formation and mixing.

"You can take a certain amount of water, and divide it up into many small drops or just a few big drops," Shaw says, explaining that it's like having a lot of sand or just a few boulders. "And just by dividing it up in different ways, you can change the optical properties of the clouds, making them brighter or darker, more or less reflective."

The differences affect how much sunlight makes it into the lower atmosphere and can reflect, buffer or trap in heat. The challenge, however, is that clouds don't blanket regions--let alone the world--in a uniform layer. Plus, on even smaller scales within clouds, mixing affects the spacing between drops, what size they are and how they are distributed throughout the clouds.


Story Source:

Materials provided by Michigan Technological University. Original written by Allison Mills. Note: Content may be edited for style and length.


Journal Reference:

  1. M. J. Beals, J. P. Fugal, R. A. Shaw, J. Lu, S. M. Spuler, J. L. Stith. Holographic measurements of inhomogeneous cloud mixing at the centimeter scale. Science, 2015; 350 (6256): 87 DOI: 10.1126/science.aab0751

Cite This Page:

Michigan Technological University. "Holodeck? Using holography to better understand clouds." ScienceDaily. ScienceDaily, 1 October 2015. <www.sciencedaily.com/releases/2015/10/151001153043.htm>.
Michigan Technological University. (2015, October 1). Holodeck? Using holography to better understand clouds. ScienceDaily. Retrieved March 25, 2017 from www.sciencedaily.com/releases/2015/10/151001153043.htm
Michigan Technological University. "Holodeck? Using holography to better understand clouds." ScienceDaily. www.sciencedaily.com/releases/2015/10/151001153043.htm (accessed March 25, 2017).