Early in the morning, and again in the evening ...

Combinations of sunlight, clouds and other weather factors have created some very artistic skies in northeast Iowa during recent days, both during the early morning sunrise in the east (photo above) and early evening sunset in the west (photo below). According to the National Weather Service, the bright reds and oranges visible in those sunrise and sunset moments are a combination of many factors, but the premise of those dominant colors stems from the fact that sunlight takes a much longer path through the atmosphere during those sunrise and sunset times than it does during the middle part of the day. Because this lengthened path results in an increased amount of violet and blue light being scattered out of the sunlight beam by a process collectively known as multiple scattering, the light that reaches an observer early or late in the day is noticeably reddened. The National Weather Service also explains that late fall and winter are the most favored times for sunrise and sunset viewing over most of the United States because air circulation is more sluggish during the summer and because the photochemical reactions which result in the formation of smog and haze that can also impact sunlight scattering and color proceed most rapidly during that summer time of year. The National Weather Service also says that clouds, such as those in the photos above, catch those last red-orange rays of the setting sun and the first light of the dawn like a theatre screen and reflect that light to the ground. A much more detailed explanation behind the sometimes brilliant sunrise and sunset views during the winter months can be found at https://www.spc.noaa.gov/publications/corfidi/sunset/.

Rate this article: 
No votes yet