Meteorology, or the science of the atmosphere, first was founded during Aristotle’s time. It was he who created the word “Meteorology” in his treatise entitled Meteorologica. Meteorology is not just the science of the atmosphere; it also includes the studies of physics and geography. When someone says they are studying meteorology, they are specifically referring to the science of the atmosphere and it’s “weather”.
“Weather”, as we know it, is the condition of the air at a particular place and time. Weather occurs in the lowest 12 miles of the atmosphere, also known as the troposphere. The upper troposphere contains high speed winds called the jet stream. Major factors which create weather are heat, pressure, wind and moisture. Another significant factor is the Earth’s geography, as it is comprised of many different average temperatures, humidity levels, and atmospheric conditions.
The Earth is encompassed by a gaseous shell: the atmosphere. Our atmosphere consists of five layers, called the troposphere, stratosphere, mesosphere, thermosphere and the exosphere. The combination of gases in the atmosphere is relatively stable. The first 99% consists of Nitrogen and Oxygen, while the last percent is a mix of more than nine other gases, such as carbon dioxide, hydrogen, and ozone. All of these gases contain similar characteristics of extreme mobility, compressibility, and capacity for expansion.
The air in the atmosphere always contains water vapor. Water vapor is an invisible gas, but it has a pronounced effect upon the weather. Vapor is contributed to the air by means of evaporation of water surfaces, soil, and living tissues. This is called atmospheric moisture, and it exists in all three stages; solid, liquid, and gas.
Most of the water vapor is absorbed by the carbon dioxide in the air, but when the level of water vapor reaches maximum capacity, the excess can fall down to earth in the form of liquid drops. Because the carbon dioxide absorbs the water, when the level of carbon dioxide increases, the maximum water capacity increases. More water vapor in the air means more vapor pressure inflicted upon the earth.
Did you know that the entire atmosphere weighs over 11 quintillion pounds? Although we can’t feel it, the air around us is always pressing down. This is called atmospheric pressure. The air at any point in the atmosphere is always compressed by the weight of the air above it. Weight of air per unit volume can be expressed as its density.
Usually, when air is under pressure, it expands with an increase of temperature. However, when air decreases in temperature, it occupies less volume, and therefore, its density increases. Dense air means a large weight amount compressed in a small unit volume. Temperature and humidity can affect barometric readings because they affect the density of the air. Air density affects the weight of a given volume of air and thus the air pressure.
The troposphere is where all...