Weather: Running Around in Circles

By Alaina Grantham
Rotunda ReporterWeather is a driving force in our lives, affecting everything from the mundane to the extreme. In the morning it dictates what we decide to wear and in the evening it dictates our dinner plans. Weathermen, or meteorologists, have built careers around studying weather patterns, trying to understand the how's and why's of weather on our planet earth.

The last 100 years have provided uncontrolled growth in the science of meteorology, or weather predicting. With the aid of satellites and computers meteorologists have been able to better understand weather patterns and can therefore predict the weather more accurately.

However, the more meteorologists learn about weather patterns the more they realize how much is left to learn. There are many, many, many, many factors that contribute to what type of weather occurs and when. Barometric pressure, temperature, time of year, moisture and local environment only begin to scratch the surface of things that contribute to the weather.

Scientists have come to understand that one of the major contributors to weather patterns on our planet is something called a convection current. A convection current is a circular air current caused by warm moist air rising after absorbing heat.

Since the sunlight hits our planet at different angles, the planet's surface is heated unevenly, which causes minor wind and weather patterns that interact with convection currents. This uneven heating is due to the fact that only a small percentage of the sun's light and energy passes into the earth's atmosphere.

The atmosphere will actually deflect most of the light and energy back into space, especially if the light hits the atmosphere at an angle. Think of it like skipping stones, when you throw a stone it has to hit the water at the right angel to skip. A stone that skips represents energy that is bounced back into space, while any stone that sinks represents energy absorbed by our atmosphere and planet.

The stone that hits the water with a more direct angle will sink sooner, or be absorbed by the stream easier. The same is true for the suns energy, near the equator in the tropic regions of the world the sun hits the planet directly and less energy is deflected leaving more energy available. This available energy is what heats the air and evaporates the water creating warm and moist air system of the convection current, because the most energy is absorbed at the equators the convection currents from this region are the primary convection currents on the planet.

In the convection currents the warm moist air rises higher into the atmosphere and spreads out, away from the equator, where it starts to cool and begins to sink. Additionally when the air starts to cool the evaporated water within the air starts to form clouds. Once the water is rained out of the air, a cool dry air is left behind, the cool dry air slowly slinks its way back down to the tropics where it once again gathers moisture and heat continuing the circle.

At first glance it seems that understanding this circular convection current would make it easy to predict the weather, but the rising and falling from the convection currents drive other air currents that in turn move the air and moisture over the surface of the entire planet. These spin off currents combine with currents that are created from the unequal heating of the planet create the often times unpredictable weather we experience.