Scientist Tom Painter examines the differences between pure and dirty snow. A rise in dust can be a critical influence on snow-fed water supplies in the American West.
Springtime flooding in southern Siberia is not unusual. Melting snow fills the north-flowing rivers in the south even as upstream sections of the river are still frozen. Floods build up behind dams of ice, or simply build under the fast flow of spring runoff. Spring of 2006 was not exceptional.