Why Green Flash Sunset Sightings Are Surging Across Coastal Skies This Winter
By James H. Sterling
Q1: Why are green flashes seen more frequently in winter months?
Winter produces cooler surface air moving over temperate coastal waters, which creates sharp temperature inversion layers. Winter offshore winds like California's Santa Ana drafts also strip away low-level pollution and ocean haze, delivering the clean line of sight required for short wavelengths to penetrate.
Q2: Can a green flash occur at sunrise as well as sunset?
Yes. The identical optical refraction and mirage mechanisms operate at sunrise. Sunrise flashes are simply harder to witness because the observer must anticipate the precise spot and second the solar disk will crest the flat horizon, whereas sunset allows observers to track the sun directly into position.
Q3: Is it possible to see a blue or violet flash?
Under extraordinary conditions with an exceptionally clear, dry, and dust-free atmosphere, the blue and violet disks can emerge. These sightings are exceptionally rare because Rayleigh scattering disperses almost all violet and deep-blue light along such long atmospheric paths, leaving green as the dominant survival color.
James Sterling reports on renewable energy developments, climate policy, ecological conservation, and green tech innovations around the globe.
