Two Satellites Observe Details of Ocean‐Atmosphere Coupling

Winds drive ocean circulations, which, in turn, establish the sea surface temperature (SST) gradients that generate the atmospheric pressure to drive winds. Identifying and explaining the close coupling of ocean and atmosphere—its causes and effects, its feedback mechanisms—is a formidable challenge. In few locations is this goal more daunting than in the eastern tropical Pacific, the site of El Niño's and La Niña's biggest temperature anomalies. Here, the circulations of ocean and atmosphere are complicated by the coastal boundary, vigorous atmospheric convection, the convergence of northern and southern hemisphere trade winds, and the change of sign of the Coriolis force at the equator.