 In a world full of vibrant color, nothing quite vanquishes the atmospheric phenomenon that is the rainbow. Everyone has awaited the arrival of a rainbow once rainfall has ceased. Almost always, the ever reliable rainbow traverses across the sky emitting light in all wavelengths thus presenting its renowned look. But what does it take for these bows of color to form? Rainbows are meteorological phenomenon that are caused by the reflection, refraction and dispersion of light in water droplets. This results in a spectrum of light appearing in a bow-like structure in the skies above. When observing a rainbow, one will notice that the outer part of the arc is red and the inner part is violet. This is caused by light being refracted when it enters a droplet of water, then reflected on the back side of the droplet and refracted again before leaving the water droplet. The rainbow effect occurs due to incoming light being reflected back over an angle range of 0 degrees and 42 degrees, with most intense light at 42 degrees. The reason the returning light is most intense at 42 degrees is because 42 degrees is known as the turning point—light hitting the outermost ring of the droplet and returning to the center at less than 42 degrees.  The amount of light that is being refracted is dependent on its wavelength, and hence its color. This is referred to as dispersion. Blue light, which has a shorter wavelength, is refracted at a greater angle than red light. But, due to the reflection of light rays from the back of the water droplet, blue light emerges from the droplet at a smaller angle. This causes blue light to appear on the inside of the rainbow arc and red on the outside of the rainbow arc.  Rainbows do not exist at one particular location either. In fact, many rainbows can exist, but only one can be observed depending on the observer’s viewpoint. All raindrops reflect and refract sunlight in similar ways, but only some light from raindrops reaches the observer’s eye. Rainbows appear to be curved due to the angle between the observer, the water droplet, and the sun. This angle perfectly creates the rainbow phenomenon between 40 and 42 degrees to the line between the observer’s head and their shadow.
Rainbows can be observed all around the globe and present a tranquil end to rainfall. Truly, rainbows are awe-inspiring enough that Pink Floyd depicted the dispersion effect on their The Dark Side of The Moon album. Everyone enjoys a rainbow that traverses across the sky and presents its dance of color, so be sure to look out and around when rain has ceased to fall to observe the atmosphere's true color. For more weather education, click here! ©2019 Weather Forecaster Alec Kownacki
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 Whether on the Great Lakes or on the coast of an ocean, everyone has felt a lake or sea breeze. A lake breeze is any wind that blows from a large body of water toward or onto a landmass. In the image above, it is displayed that low and high pressures play a key role in the development of these winds. With a lake or sea breeze, high pressure is lower near the surface of the water and low pressure is lower near the surface of the landmass. Wind prefers to travel from high to low pressure so this is where a lake or sea breeze comes from. Air temperature also plays a role in the formation of these winds. During the daytime when the landmass surface has undergone a few hours of solar heating, the air temperature on land rises above the air temperature over the water surface. This helps set up the high and low pressure system, thus creating the land or sea breeze phenomenon.  How do lake or sea breezes affect localized weather and what effects do these breezes have? A lake or sea breeze front is a weather front created by said lake or sea breeze. This front is also commonly known as a convergence zone. This front forms when the cold air from the water meets the warmer air from a landmass, which creates a boundary similar to a shallow cold front. With enough energy, this front can create cumulus clouds and become unstable if there is enough humidity, which can trigger thunderstorm development.
If there is already instability in the surrounding atmosphere, lake or sea breezes can be the factor needed to trigger thunderstorm development. Also, if a lake or sea breeze front collides with another frontal boundary, this too can trigger convection and thunderstorms development. This is commonly seen in the Florida panhandle. Sea breezes from the west coast of Florida and the east coast of Florida collide with one another near the middle of the landmass and cause thunderstorms to develop. Next time you are on the beach and notice a rather strong breeze coming over the water, that very well could be a lake or sea breeze. Also, to confirm this, look inland and see if cumulus clouds are visible. This is a good indicator that a lake or sea breeze has initiated cloud development over land. For more weather education, click here! ©2019 Weather Forecaster Alec Kownacki |
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