When rain falls on snow, Arctic animals starve
By Christopher Joyce
When wildlife biologists visited a remote spot in Canada called Banks Island in the spring of 2004, they discovered thousands upon thousands of dead musk oxen. It took years to determine the cause. They called it “rain-on-snow” — the worst case of it ever documented. “Long story short, about 20,000 musk oxen starved to death because of this event,” says geologist Jaakko Putkonen. It was a “humongous event” that took place in the fall of 2003. Putkonen, who is a professor at the University of North Dakota, has since discovered a few anecdotal accounts of big rain-on-snow events that killed reindeer in the Arctic and Scandinavia. What happens is this: unusually warm weather drops rain on top of snowpack. The rain either pools at the surface or trickles down to the soil below the snowpack, then freezes into a sheet of ice. Musk oxen, which are shaggy, cow-sized animals that weigh hundreds of pounds, can’t break through the ice to browse on plants underneath the snow. Sooner or later, they starve. … “If the climate warms up, it doesn’t just grow palm trees in sunny Fairbanks, Alaska,” says Tom Grenfell, an atmospheric scientist at the University of Washington. “It creates more storms and mixes up the atmosphere a lot more.” That could mean more rain-on-snow events, he says. …
