From space, it looks almost elegant: a narrow plume cascading off the Pacific Ocean, spilling gently over the California coast. But from the ground, it looks like trouble: flash flooding, landslides and power outages. California is enduring the effects of an atmospheric river, a meteorological phenomenon where converging air systems funnel wet air into a long, riverine flow that dumps large amounts of rain when it makes landfall. "Atmospheric rivers can transport volumes of water many times that of the Mississippi River," says Dr. Daniel Swain, a climate scientist with UCLA, the National Center for Atmospheric Research, and the Nature Conservancy of California. Daniel joined Short Wave's Aaron Scott to explain where these "rivers" of air come from, how climate change is fueling more of them, and why you're a lot more likely to have heard of them if you happen to live on the west coast of almost any continent.