Mar Chiquita Rainbow

Provided by: John Coppens, Catholic University at Córdoba
Summary Author and Editor: John Coppens

This grand double rainbow formed after a copious rain storm on Mar Chiquita in north central Argentina, in November of 2007. We were on a 19 mile (30 km) kayak trip when we observed the double bows. Note the brightened area beneath the primary bow and above the water surface. This region appears quite bright compared to the darkened band between the primary and secondary bows (Alexander's dark band); an area devoid of light rays scattered toward the observer's direction.

Mar Chiquita, Spanish for "little sea," is a salt lake about 358 miles NW of Buenos Aires in the provinces of Cordoba and Santiago del Estero on the southern edge of the Gran Chaco. It is Argentina's largest lake although its size and salinity vary greatly with the water level. The lake is a nest site for the Chilean Flamingo (Phoenicopterus chilensis) and other birds.