Why is it light in all of these pictures?

January 18, 2010 by ianschwartz1 4 Comments

Here in Antarctica, it is summer, which means that the weather we are experiencing is relatively mild and calm most of the time. It also means that it is light 24 hours a day!

We have been well prepared for the weather by all of the equipment we have been issued that is extremely warm. The constant daylight, on the other hand, has been more difficult to adjust to.

We are finding that we often lose track of what time it is and without a watch it would be very difficult for us to judge the time. We also are finding that even though we are tired we don’t feel always feel tired until we cover our eyes and make it dark.

We are at the bottom of the Earth and because of the orientation of the Earth in it’s orbit, it is light all the time here. In the winter, on the other hand, it would be dark here 24 hours a day. Some of the people we have met here who have spent close to an entire year down here have seen the spring and fall here. Those people told us that during those times the light is almost like sunrise or sunset.

Some people think that the seasons are caused by the elliptical orbit of the Earth causing us to pass closer to the Sun at certain times of the year. This is not true!

In fact, the Earth is tilted on its axis at 23.5 degrees. Because of this tilt, as the Earth travels in its orbit around the Sun parts of the Earth receive more direct sunlight during certain times of the year. By looking at the figure below, you will notice that right now the Earth is in a position where the Southern Hemisphere is receiving more direct sunlight than the Northern Hemisphere.

In Antarctica, we are so close to the south pole that we are currently receiving 24 hours of sunlight each day. We are at about 77 degrees south (so we are 13 degrees from the south pole). Because of our location on the Earth’s surface and the position of the Earth in its orbit, the sun is at about 45 degrees above the horizon all day. Each day it gets a little bit lower on the horizon as we move closer to the fall season in Antarctica.

Source: http://www.crh.noaa.gov/images/ind/seasons.jpg