The phenomenon "green flash" occurs during which time period?

The "green flash" phenomenon is a remarkable optical event that occurs just before sunrise or just after sunset. It is characterized by a brief flash of green light that can be observed when the conditions are right. This event occurs due to the refraction of sunlight in the Earth's atmosphere, where the light is split into its various colors. The green color is visible for only a short period—typically just a couple of seconds—because the sun is just at or slightly below the horizon.

In contrast, during noon, when the sun is at its highest point in the sky, the light does not undergo the same refraction effects that lead to the green flash. Similarly, cloudy weather and heavy rainfall can obscure the view of the horizon and diminish the chances of witnessing this phenomenon, as they often scatter sunlight more than clear atmospheric conditions would. Thus, the phenomenon is specifically associated with the transitional times of dawn and dusk, making the correct time period during which the green flash occurs at sunrise or sunset.