Fast Facts: Red Sky at Night, Sailors’ Delight…

UNDATED一 Many know the back half of this age-old adage, red sky at night, sailors’ delight, red sky in the morning, sailors take warning. Many may also know that the saying is more than just lore, atmospheric science actually supports this old bit of sailing wisdom. Those in mid-latitude locations such as Oregon, Northern California, Wyoming, Virginia, North Carolina, northern Germany, and Poland can actually take advantage of this. There are two atmospheric-related factors that make this possible. One, storm systems in the middle latitudes generally move west to east and the red color in the sky is the result of sunlight reflecting off clouds. Low pressure is associated with bad weather and high pressure with good weather. Low pressure causes air to converge to try to “fill” the low, and converging air causes upward motion, which in turn produces clouds and precipitation. The reddish color results from scattering of sunlight by suspended particles and aerosols in the atmosphere, and the sun’s rays pass through a greater length of atmosphere at sunrise and sunset than at any other time of day. In addition, aerosol, dirt, and dust concentrations are maximized in the lowest layers of the atmosphere when the atmosphere is...