February 1, 2007 By recording the shape of snowflakes seen under a magnifying glass and submitting the information to a NASA Web site, the public can contribute to a global snow-tracking network. Different types of snowflakes are associated with different temperatures -- dendrite plate for a typical snowflake, needle-like shapes for those originating in very cold clouds. The information helps NASA track storms globally, and identify which storms are just beginning or starting to peter out.
When a fresh batch of snow falls, it's not long before the fun starts! Now, add a little more fun by catching snow. It's a fun, easy way to help planetary scientists collect and identify snowflakes for the new Global Snowflake Network.
"We're trying to produce teams all over the world that look at snow wherever it falls and then identify the shape and any other characteristics of the snow," Peter Wasilewski, a planetary scientist at NASA Goddard Space Flight Center in Greenbelt, Md., tells DBIS.
Catch snow on dark paper, and then use a magnifying glass to look closely at each snowflake. The shapes tell a lot about winter weather.
Wasilewski says, "The shape of a snowflake says something about the temperature and the moisture content in the clouds where the snowflakes form and begin to grow."
Just below freezing temperatures, snowflakes form shapes called plates. A dendrite plate looks like a typical snowflake. As the temperature drops, flakes turn into columns and look more like needles. The colder it gets, the shapes switch between plates and columns.
Spotting unique shapes helps track a storm's movement.
"You can see that the beginning of the storm, the middle of the storm, and the end of the storm all have different snowflake shapes," Wasilewski says. "Each snowstorm has a story to tell."
You can then record your snowflake shapes online, submit them, and help scientists get a global picture of snow
BACKGROUND: NASA Goddard is launching the Global Snowflake Network, a project in which the general public is encouraged to go out and collect and classify falling snowflakes to build up a global database of snowflake data. The goal is to provide an interactive online data resource for the characterization of snowfall and related weather systems. Sites will include homes, schools and other organizations, each of which will have one person dedicated to the identification and Web-based entry of snowflake shapes collected during snowfall events. The serial record will then be archives with serial satellite image records. The public gets to participate in real science while learning more about snow and snowflake formation, as well as helping meteorologists track the weather.
ABOUT SNOWFLAKES: Snow is a form of precipitation. Rising warm air carries water vapor high into the sky, where it cools and condenses into water droplets. Some vapor freezes into tiny ice crystals, which can attract cooled water drops to form snowflakes. As snowflakes fall, they meet warmer air and melt into raindrops, unless temperatures are below freezing close to the ground: then we get snow. A snow crystal is a single crystal of ice. It usually forms the shape of a hexagonal prism, but as the crystals grow, branches sprout from the corners, creating more complex shapes. Conditions such as temperature and humidity in the atmosphere can influence a snowflake's shape.
WEATHER SHAPING: A great deal of information about the atmosphere dynamics and cloud microphysics can be derived from the serial collection and identification of the types of snow crystals during the progress of a snowstorm. The shapes of snowflakes vary over the winter season, with the source of the weather system, and during the progress of any given snowfall. So snowflake shapes are a proxy for conditions in the weather systems responsible for the snowfall. A global snowflake network can therefore be of great value to those who work in winter meteorology. Integrating data entry into a Web-based site will allow tracking of snowstorms as they travel across the globe. Students will be able to see the actual relationships of climate, temperature and other atmospheric features.
The American Meteorological Society and the American Geophysical Union contributed to the information contained in the video portion of this report.
Further information on the Global Snowflake Network is available at http://learners.gsfc.nasa.gov/HOWmedia/SnowCollProto/