Plain Language Summary
Atmospheric rivers occur thin, river-like, streams of moisture connecting the mid- and high-latitudes to the tropics often associated with extratropical storms. These events are regions that have large amounts of moisture and can generate heavy precipitation. We show that moisture and energy fueling the ARs do not come from the ocean directly beneath the ARs. First, we use a dataset derived from satellite retrievals of surface winds to demonstrate that the energy transferred into ARs from the ocean are weaker than usual during AR events. Then we use a global climate model to show that the origins of the moisture in the ARs arrives via atmospheric transport from regions outside of the ARs, farther away and nearer to the equator.