KidzTube
Welcome
Login / Register

Scientists Create First-Ever 3-D Model of a Melting Snowflake

Thanks! Share it with your friends!

URL

You disliked this video. Thanks for the feedback!

Sorry, only registred users can create playlists.
URL


 Physics   |   Science
 Find Related Videos  added
122 Views

Description

This visualization is based on the first three-dimensional numerical model of melting snowflakes in the atmosphere, developed by scientist Jussi Leinonen of NASA's Jet Propulsion Laboratory in Pasadena, California. A better understanding of how snow melts can help scientists recognize the signature in radar signals of heavier, wetter snow -- the kind that breaks power lines and tree limbs -- and could be a step toward improving predictions of this hazard.

The model reproduces key features of melting snowflakes that have been observed in nature: first, meltwater gathers in any concave regions of the snowflake's surface. These liquid-water regions merge as they grow and eventually form a shell of liquid around an ice core, finally developing into a water drop.

The visualization shows a typical snowflake less than half an inch (one centimeter) long. The snowflake is composed of individual ice crystals whose arms became entangled when they collided in the air. The extremities of the arms melt first because they are more exposed to heat from the surrounding air. Water first fills small cavities within the ice crystals, and then these overflow, allowing water to pool into droplets.

"I got interested in modeling melting snow because of the way it affects our observations with remote sensing instruments," Leinonen said. A radar "profile" of the atmosphere from top to bottom shows a very bright, prominent layer at the altitude where falling snow and hail melt, much brighter than the layers above and below. "The reasons for this layer are still not particularly clear, and there has been a bit of debate in the community," Leinonen explained.

Simpler models can reproduce the bright melt layer, but a more detailed model like this one can help scientists to understand it better, particularly how the type of melting snow and the radar wavelengths used to observe it relate to the brightness of the layer.

A paper on the numerical model, titled "Snowflake melting simulation using smoothed particle hydrodynamics," recently appeared in the Journal of Geophysical Research - Atmospheres. Music: Creeping Cauldron by Benjamin James Parsons, Floating on Kisses by Lennert Busch, and Strangely Calm by Brice Davoll Complete transcript available.

This video is public domain and along with other supporting visualizations can be downloaded from the Scientific Visualization Studio at: http://svs.gsfc.nasa.gov/12908

Credit: NASA's Goddard Space Flight Center/LK Ward

If you liked this video, subscribe to the NASA Goddard YouTube channel: http://www.youtube.com/NASAExplorer
Follow NASA’s Goddard Space Flight Center
· Facebook: http://www.facebook.com/NASA.GSFC
· Twitter http://twitter.com/NASAGoddard
· Flickr http://www.flickr.com/photos/gsfc/
· Instagram http://www.instagram.com/nasagoddard/
· Google+ http://plus.google.com/+NASAGoddard/posts

Post your comment

Comments

Be the first to comment






RSS