In-Depth Notes on Atmosphere and Weather Concepts

Key Concepts in Atmospheric Science

Changes in Insolation

  • Insulation: Refers to the incoming solar radiation that is absorbed by Earth’s surface.
  • Factors Affecting Insolation:
    • Decrease in Cloud Cover: More sunlight reaches the surface, thus increasing insolation.
    • Decrease in Atmospheric Transparency: A reduction in clarity of the atmosphere leads to less insolation reaching the surface.
    • Increase in Duration of Daylight: More hours of sunlight results in greater insolation.
    • Increase in Nitrogen Gas: Does not significantly affect insolation; mostly inert in terms of absorption of sunlight.

Average Surface Temperature and Latitude

  • Temperature-Latitude Relationship: Average surface temperature decreases as latitude increases (closer to the poles).
  • Typical Patterns: Graphs can depict this inverse relationship.
  • Examples of Graph Forms: Various line graphs can illustrate distinct temperature profiles based on latitude.

Composition and Structure of the Atmosphere

  • The atmosphere is made up of:
    • Nitrogen (78%)
    • Oxygen (21%)
    • Argon (1%)
    • Other gases (
  • Atmospheric Cycling: Gases in the atmosphere interact and their composition can vary based on location.

Weather Definition and Variables

  • Weather: The short-term atmospheric conditions, including temperature, air pressure, wind, and water vapor.
  • Main Area of Study: Most measurements occur in the Troposphere (the lowest layer of the atmosphere).

Layers of the Atmosphere

  1. Troposphere: Lowest layer, contains most water vapor, where weather occurs.
  2. Stratosphere: Houses the ozone layer which absorbs UV light.
  3. Mesosphere: Temperature decreases with altitude, protects Earth from meteoroids.
  4. Thermosphere: Extremely thin air, includes the ionosphere where auroras occur, temperature increases with altitude.

Humidity and Related Terms

  • Specific Humidity: The actual water vapor content in the air.
    • Limited by air temperature; warmer air holds more moisture.
  • Relative Humidity: Compares actual water vapor to the maximum capacity at a specific temperature; expressed as a percentage.
    • Measured using a Psychrometer (wet and dry bulb thermometers).
  • Dew Point: The temperature at which the air becomes saturated, leading to condensation and cloud formation if the temperature drops.

Weather and Precipitation

  • Higher Relative Humidity: Indicates a greater likelihood of cloud formation and therefore precipitation.

Example Observations from Data Table

  • Albany Weather Data: Provides temperature, dew point, cloud cover, pressure, wind direction, and speed.
  • Rain Likelihood: If dew point is significantly lower than air temperature, it suggests lower relative humidity and thus less likelihood of rain; e.g., at temperatures of 58°F with a dew point of 36°F.

Cloud Formation

  • Process Leading to Cloud Formation: Changes in temperature and pressure at various altitudes can lead to air saturation and subsequent condensation, forming clouds.
  • Phase Changes During Cloud Formation: Involves the condensation of water vapor to form droplets, visible as clouds.