Atmosphere Overview

Introduction to Atmospheric Science

• Prof. Faiaz Khaled, PhD, Texas Tech University

• Focus on weather and climate, composition and structure of the atmosphere.

Weather vs. Climate

• Weather: Current atmospheric state; short-term phenomena.

• Climate: Long-term average of weather patterns (over 30 years).

Atmosphere Composition

• Composed of gases, particles, and clouds.

• Permanent gases remain constant; variable gases fluctuate.

• Major components:

  • Nitrogen: 78%

  • Oxygen: 21%

  • Water vapor, CO2, ozone, argon, methane (variable gases).

Importance of Water Vapor

• Primary source for cloud formation and plays a significant role in weather.

• Enters atmosphere via evaporation and transpiration.

Ozone Layer

• Absorbs UV radiation; critical for temperature control but can act as a pollutant at surface level.

Atmospheric Structure

• Layers:

  • Troposphere: Weather occurs, 10-20 km deep, varies by season.

  • Stratosphere: Ozone layer, temperature increases with altitude.

  • Mesosphere: Less defined, colder temperatures.

  • Thermosphere: Contains ionosphere, where auroras occur.

General Characteristics of the Atmosphere

• Composed of gas and particles, has mass and is influenced by gravity.

• Density decreases with altitude; atmospheric pressure also decreases with height.