KOTA Territory Weather School: Seasons
We just transitioned into spring and many of us are ready for summer so we can forget about any more of these snowstorms. With the seasons changing so drastically, we will dive into explaining them a little bit more.
We will start off with the season we just left behind, Winter. The Winter Solstice is typically around December 21, give or take a few days. Direct sunlight shines over the Tropic of Capricorn, which is 23.5° south of the equator. During this time, the days are longer in the southern hemisphere, where it is summer, and shorter in the northern hemisphere, where it is winter.
Locations within the Antarctic Circle receive 24 hours of daylight. Those at the Tropic of Capricorn receive 13.5 hours of daylight. The closer you get to the Antarctic Circle, the longer amount of daylight. At the equator, 12 hours of daylight are observed. Moving into the Northern Hemisphere, the amount of daylight is 10.5 hours at the Tropic of Cancer and less the farther north you go. locations within the Arctic Circle receive no sunlight, 24 hours of darkness.
Next up, the Vernal Equinox, better known as spring. The Vernal Equinox is typically around March 20, give or take a few days. Sunlight shines directly over the equator. All areas from the Antarctic Circle, to the equator and the Arctic Circle receive nearly 12 hours of sunlight. The same can be said for the Autumnal Equinox, or fall, as all locations receive 12 hours of sunlight a day. The Autumnal Equinox occurs around September 20, give or take a few days.
Last but not least, the Summer Solstice. The first day of summer is typically around June 21, give or take a few days. Direct sunlight is over the Tropic of Cancer, which is 23.5° north of the equator. Daylight is longer in the northern hemisphere, where it is summer, and shorter in the southern hemisphere, where they observe winter. The amount of daylight is flipped from the Winter Solstice per hemisphere.
The Arctic Circle receives 24 hours of daylight, the Tropic of Capricorn receives 13.5 hours of daylight, longer the farther north you go, and the equator receives an even 12 hours of daylight. For the southern hemisphere, the Tropic of Capricorn receives 10.5 hours of daylight and less for those closer to the Arctic Circle. For those in the Arctic Circle, no daylight is received and it is 24 hours of darkness.
Now, let’s take a look at why leaves change colors. When the weather starts to cool off and the sun angle gets lower in the sky/less daylight, the tree's chlorophyll breaks down, leaving the other chemicals preset, that cause the color changes. Those other chemicals include xanthophyll, carotene and anthocyanin. To get the brightest, most vibrant colors, it is ideal to have a dry late summer and have autumn observe sunny days and cool night.
Lastly, we will talk about why sunsets are red. It takes less time for sunlight to travel to earth during much of the day, outside of morning and evening hours. As the sun is near sunrise or sunset times, it takes longer for the sunlight to reach the earth. The blue and violet light have short wavelengths, which is why we have a blue sky for much of the day, but once we reach the point where the sunlight is farther away, much of the blue/violet shortwave light is scattered away by air and dust particles in the atmosphere. Red and orange light has a somewhat longer wavelength, therefore which is what is left for us to see once the blue/violet light is scattered away.