Tropical atmospheric circulation and precipitation changing



[1] As Earth's climate has warmed over the past several decades, atmospheric and hydrological cycle changes are being observed globally and regionally. For instance, Zhou et al. analyzed trends in the hydrological cycle in the tropics over the past 20–30 years using precipitation, cloud, and radiation data. In particular, the researchers looked at Hadley and Walker cell atmospheric circulation patterns. Hadley circulation is a major circulation pattern in the tropical atmosphere in which air masses, warmed by the Sun, rise near the equator, then travel poleward, sink back toward Earth's surface in the subtropics, and return to the equator. Similarly, in the Walker circulation, air rises over the warmer parts of the oceans near the equator, travels zonally toward the colder parts, then sinks back to the surface. There are indications that both of these circulation patterns are changing with global warming and could be altering precipitation and cloud radiation distributions in the tropical regions. (Journal of Geophysical Research-Atmospheres, doi:10.1029/2010JD015197, 2011)