Sunset at Morro Bay, California

September 15, 2017

MorrowBay1_7P7A7627 (3)

MorrowBay2_7P7A7618 (4)

September 2017 Viewer's ChoicePhotographer: Mark Ritter
Summary Authors: Mark Ritter; Jim Foster

Due to localized differences in atmospheric stratification, the solar disk can appear fragmented at sunset or sunrise. Because the index of refraction varies with height above the surface, temperature gradients as well as differences in water vapor in the lower atmosphere cause the Sun to take on odd shapes, such as the one shown above over Morro Bay, California. While hugging the horizon, the Sun is often flattened (bottom photo). This is because sunlight coming from the bottom part of the Sun passes through a little more of Earth's atmosphere than sunlight that emanates from the Sun's top portion. So sunlight coming from the bottom of the Sun is refracted upwards slightly more than that coming from the top-side. Note the green flash along the upper rim of the solar disk on the bottom photo. Photo taken  on August 7, 2017.
Photo Details: Top - Camera Model: Canon EOS 5D Mark III; Lens: TAMRON SP 150-600mm F/5-6.3 Di VC USD G2 A022; Focal Length: 600mm; Aperture: ƒ/13.0; Exposure Time: 0.0080 s (1/125); ISO equiv: 1000; Software: Adobe Photoshop Lightroom 6.12 (Macintosh). Bottom: same except - Exposure Time: 0.0063 s (1/160); ISO equiv: 400.