SNOW SCIENCE: CRYSTAL CLUES TO CLIMATE CHANGE, WATERSHEDS
HIGHMOUNT, N.Y.—Capturing snowflakes isn’t as easy as sticking out your tongue.
At least not when you’re trying to capture them for scientific study, which involves isolating the tiniest of crystals on a metal card printed with grid lines and quickly placing them under a microscope to be photographed.
“They are very tiny and they are close to the melting point,” Marco Tedesco of Columbia University said as he set up his microscope beside a snowy field. “So as soon as they fall, they will melt.”
Tedesco recently led a team of three researchers who trudged through the snowy hills of New York’s Catskill Mountains with cameras, brushes, shovels, a drone and a spectrometer to collect the most finegrained details about freshly fallen snowflakes and how they evolve once they settle to the ground.
That data could be used to provide clues to the changing climate and validate the satellite models used for weather predictions. It also could provide additional information on the snow that falls into New York’s City’s upstate watershed, flows into reservoirs and fills the faucets of some 9 million people.
“We’re talking about sub-millimeter objects,” Tedesco said as he stood in shindeep snow. “Once they get together, they have the power, really, to shape our planet.”
This is the pilot stage of the “X-Snow” project, which organizers hope will involve dozens of volunteers collecting snowflake samples next winter. The specimens Tedesco spied under his microscope on a recent snowy day displayed more rounded edges and irregularities than the classic crystalline forms. This is characteristic of flakes formed up high in warmer air.
Pictures and video from the drone will be used to create a three-dimensional model of the snow’s surface. “There are a lot of things that happen that we can’t see with our eyes,” said Tedesco, a snow and ice scientist at Columbia’s Lamont-Doherty Earth Observatory. “When snow melts and re-freezes, the grains get bigger. And as the grains get bigger the snow absorbs more solar radiation.”