Atmospheric Science
Introduction
Atmospheric science is the study of the Earth's atmosphere, its processes, the effects other systems have on the atmosphere, and the effects of the atmosphere on these other systems. It is an interdisciplinary field that involves meteorology, climatology, atmospheric physics, and atmospheric chemistry.
Atmospheric Composition
The Earth's atmosphere is a mixture of gases, commonly known as air, which surrounds the planet and is retained by Earth's gravity. The atmosphere protects life on Earth by absorbing ultraviolet solar radiation, warming the surface through heat retention (greenhouse effect), and reducing temperature extremes between day and night (the diurnal temperature variation).
The principal components of the atmosphere are nitrogen (78%) and oxygen (21%), with trace concentrations of water vapor, carbon dioxide, and other gaseous molecules. The exact composition can vary depending on the location, altitude, and weather conditions.
Atmospheric Layers
The atmosphere can be divided into five main layers: the troposphere, stratosphere, mesosphere, thermosphere, and exosphere. Each layer has unique characteristics and is defined by changes in temperature, pressure, and chemical composition.
Troposphere
The troposphere is the lowest layer of the atmosphere, extending from the Earth's surface to about 8 to 15 kilometers high. This is where weather occurs, and it contains about 75% of the atmosphere's mass and 99% of its water vapor.
Stratosphere
Above the troposphere is the stratosphere, which extends from about 15 to 50 kilometers high. The stratosphere contains the ozone layer, which absorbs and scatters the solar ultraviolet radiation.
Mesosphere
The mesosphere is above the stratosphere, extending from about 50 to 85 kilometers high. Meteors burn up in this layer upon entering the Earth's atmosphere, creating what we call shooting stars.
Thermosphere
The thermosphere is the fourth layer of the atmosphere, extending from about 85 to 600 kilometers high. The northern and southern lights occur in the thermosphere.
Exosphere
The exosphere is the outermost layer of the atmosphere, extending from the top of the thermosphere to about 10,000 kilometers. This is the layer where atoms and molecules escape into space.
Atmospheric Pressure and Temperature
Atmospheric pressure and temperature are two fundamental aspects of atmospheric science. Atmospheric pressure is the force per unit area exerted against a surface by the weight of air above that surface in the Earth's atmosphere. It decreases with increasing altitude. Temperature, on the other hand, varies greatly at different layers of the atmosphere, with the lowest temperatures found in the mesosphere and the highest in the thermosphere.
Atmospheric Dynamics
Atmospheric dynamics involve the study of the motions of the atmosphere and the forces that cause them, including the principles of fluid dynamics. This field is crucial for understanding weather patterns, climate change, and other atmospheric phenomena.
Atmospheric Chemistry
Atmospheric chemistry is a branch of atmospheric science in which the chemistry of the Earth's atmosphere and that of other planets is studied. It is a multidisciplinary field of research and draws on environmental chemistry, physics, meteorology, computer modeling, oceanography, geology and volcanology, and other disciplines.
Atmospheric Phenomena
Atmospheric phenomena are observable events that occur in the atmosphere. These phenomena include weather events such as thunderstorms, hurricanes, and tornadoes, as well as atmospheric optical phenomena such as rainbows, halos, and sun dogs.
Conclusion
Atmospheric science is a vital field of study that helps us understand and predict weather patterns, climate change, and other atmospheric phenomena. It is a multidisciplinary field that draws on various scientific disciplines, including physics, chemistry, meteorology, and environmental science.