Winter Solstice Explained

Bells are ringing, the air is turning much cooler, the malls are flooded with consumers, and students at A&M are taking a break from the stress of classes. It only means one thing, winter is right around the corner. The corner is so close that you have to be careful when you make the turn so you don't mess up your tires.

As of 11:30pm tonight, the Winter Solstice will occur. At this time, winter will officially arrive for us here in the northern hemisphere. This whole solstice thing is a very simple concept. All this really means is that the suns rays will be directed over the Tropic of Capricorn, which is located at 23.5°S latitude. If you are not familiar with this location, check out the following image.

What is interesting about the earth, is that it is not a perfect sphere, and it does not sit upright. The Earth is a shape called a spheroid. Around the equator, the Earth actually bulges out, kind of like when you eat too much at Thanksgiving dinner.

Furthermore, the Earth is tilted at a 23.5° angle. Due to this tilt, and rotation around the sun, this is what gives us seasons. During the winter solstice, the sun rays are directed at 23.5° south due to the tilt. This means that the northern hemisphere will not have as much energy from the sun. Due to this lack in energy, the temperature tends to go down. This is why it is colder in the winter because of less sun energy.

Finally, this is the shortest day of the year in terms of amount of daylight. From the winter solstice to the summer solstice that occurs in June, daylight will begin to grow over this period.

Overall, due to the Earth's tilt and relation to the sun, seasons change and amount of daylight changes too during the year. The last image will give you a good indication of the yearly cycle of the seasons.