Zodiacal Light and the Loop Current

A cold front approaches the peninsula of Florida this morning.  Deep convection occurring over the Gulf of Mexico's Loop Current is indicated by the blues and greens in the enhanced satellite image (above).   That activity will likely die down as it approaches the cooler waters near the peninsula of Florida.

After this frontal system passes, skies should again be clear enough for plenty of evening stargazing and maybe even a glimpse of the zodiacal light.

The Loop Current feeds the Florida Current that transports significant amounts of heat poleward.  It also transports surface waters of tropical origin into the Gulf of Mexico and is fed by the Caribbean Current and the Yucatan Current.

Zodiacal Light

The ghostly glow sometimes visible in the early evenings -- now through March -- is called zodiacal light.

Ancient Romans thought this spooky haze was due to far-off campfires below the horizon, while the ancient Greeks said that it must be caused by distant volcanic eruptions.

In the mid-16th century some speculated that the zodiacal light was the outstretched atmosphere of our sun.

Today we know that the zodiacal light is actually caused by sunlight scattering off countless grains of microscopic interplanetary dust spread out to beyond the orbit of Mars.  The vast majority of this dust is concentrated within the plane of the inner solar system near the sun, making the grains' combined light appear along the ecliptic  (the path in the sky each planet follows).  

This faint light show is best seen during early spring and autumn, when the ecliptic line is nearly perpendicular to the horizon, as seen from the Northern Hemisphere.  Its also best to be far from the lights of cities which produce a similar -- albeit artificial -- effect that we sometimes refer to as light pollution.