Anthony Davis, age 10, of Hope Hull, Alabama, for his question:

Why is the Arctic so cold?

During the year, the sun sheds the same amount of daylight on the Arctic and the equator. In fact, when you total up all the hours of day¬light and darkness, you find that every spot on earth gets six months of day and six months of night during the year. The tropics get their full share of warmth from the sun. But several things happen to steal the warmth from the sunshine that falls on the Arctic.

The North Pole gets a long winter night that lasts six months, then a long summer day that lasts six months. It nestles under the Arctic Sea, in the middle of the Arctic region, inside the Arctic Circle. Other places in this region have long dark winters when the sun does not rise for sev¬eral days, or weeks or months. Since the earth gets its warmth from the sun, the ground gets very cold during the Arctic winter.

But you would think that it has time to warm up during the Arctic summer when the sun shines 24 hours a day. Actually things get warm enough to melt most of the ice from the polar sea. The ground thaws a few inches deep and the Arctic tundra land sprouts a carpet of little plants, decked with masses of pretty flowers.

The sun shines and shines on for days and days    and never dips be¬low the horizon. But it does not shed enough warmth to thaw the permanently frozen ground below the soggy surface. This is because warmth is stolen from the sunbeams before they reach the ground. Some of the sun's warmth is absorbed by the air as its rays pierce down through the stmosphere. Because the earth is a globe, sunbeams must slope through a thicker slice of air to reach the Arctic. They lose more heat on the way down.

Also, a lot of the sun's warmth is reflected back up into the sky. Sometimes heavy clouds shut out the sunshine and stop almost half of its warmth from reaching the ground. If there still is snow around, it re¬flects back three quarters of the warmth in the sunshine.

The air also steals heat from the Arctic. The global atmosphere  circulates in patterns and the North Pole is a spot where great masses of air descend down to the ground. This descending air is cool because it is heavy. It pushes out from the pole to the Arctic Circle chilling the ground as it goes. It also creates lots of clouds that stop warm sunshine from reaching the surface.

It's too bad, but the long Arctic summer just isn't warm enough to banish the cold of the long winter night.

The Arctic is robbed of its fair share of the sun's warmth mainly because the earth is round and tilted on its axis. This makes the North Pole bow to the sun during the summer and turn away from the sun during the winter. Meantime, the summer sunbeams have to slant down long slopes through the atmosphere to reach the ground. And some of the Arctic's rightful warmth is stolen by masses of cool, descending air.