Now that winter has passed, those of us who live in cold climes can once again appreciate the beauty of snowflakes without feeling the urge to curse them for making us dig out the shovel. And if ever snowflakes looked lovely, it's in these images shot by a high-speed camera system developed specifically to photograph them in 3D as they fell.
"Until our device, there was no good instrument for automatically photographing the shapes and sizes of snowflakes in free fall," says Tim Garrett, an associate professor of atmospheric sciences at the University of Utah and one of the developers of the cam known as MASC, or Multi-Angle Snowflake Camera. "We are photographing these snowflakes completely untouched by any device, as they exist naturally in the air."
MASC -- under development for three years -- takes 9- to 37-micron-resolution stereographic photographs of snowflakes from three angles while simultaneously measuring the speed of their fall, a highly influential factor in the location and lifetime of a storm.
The system, made by University of Utah spinoff Fallgatter Technologies, includes three industrial-grade high-speed cameras: two 1.2-megapixel cams and a 5-megapixel shooter. The cameras are triggered by IR motion sensors that are sensitive to snowflakes ranging from 100 micrometers to 3 centimeters (about 1.2 inches) in size and designed to filter out slow variations in ambient light. The system's superspeedy exposure time? One-40,000th of a second.
NASA and the U.S. Army helped fund the development of the camera, and the National Science Foundation funded the filming of the snowflakes over the past two winters at Alta Ski Area, about 25 miles southeast of Salt Lake City. One MASC is situated at an elevation of 8,500 feet, the other at 10,000 feet.
The goal of the system, says Garrett, a specialist in the area of cloud physics, is to improve computer simulations of falling snow and how it interacts with radar. The hope is that the data can be used to improve the use of radar for weather and snowpack forecasting, and reveal more about how snowy weather can degrade microwave (radar) communications. Today's weather forecasts, Garrett says, still use snowflake research done by hand in the '70s, when flakes were collected on plastic wrap, photographed, and melted to determine their mass.
"These early researchers got only a few hundred images over two years because they had to collect each snowflake individually by hand," Garrett says in a statement. "Our snowflake camera can automatically collect thousands of snowflake photographs in a single night."
The pleasant side effect, of course, is really pretty pictures. Click on our gallery below to see some of them.