Ribbons of water vapor called atmospheric rivers wind through the troposphere, moving the planet's moisture from near the equator toward the poles. These airborne waterways are responsible for about 20 to 30 % of annual rain and snow in parts of Europe and the United States, and more than 40 % in East Asia during the region's warm season. Climate change is expected to alter the timing and distribution of atmospheric rivers, potentially redistributing global water supplies. In a study published in Journal of Geophysical Research: Atmospheres , Zhang and others used a suite of climate models called the Coupled Model Intercomparison Project Phase 6 (CMIP6) to examine how the prevalence of atmospheric rivers has already changed and will continue to change as a result of global warming from 1980 to 2099. (Saima May Sidik, American Geophysical Union, more at phys.org)