Weather and Climate Notes
Water Cycle
- Components of the Water Cycle:
- Precipitation
- Evaporation
- Groundwater
- Lakes
- Glaciers
- Runoff
- Wind
- Transpiration
Energy Transfer
- Latent Heat:
- Heat required for phase changes (e.g., melting, evaporation, condensation).
- Absorbed during melting and evaporation, released during freezing and condensation.
Evaporation and Saturation
- Water vapor enters dry air until the process stabilizes; the air becomes saturated when evaporation equals condensation.
- Saturation: Air is saturated when it cannot hold any more water vapor.
Vapor Pressure
- Actual Vapor Pressure: Pressure exerted by water vapor in the air.
- Saturation Vapor Pressure: Maximum pressure water vapor can exert at a given temperature.
- Relative Humidity (%) = (Actual Vapor Pressure / Saturation Vapor Pressure) × 100
Humidity Concepts
- Absolute Humidity: Mass of water vapor per volume of air.
- Specific Humidity: Mass of water vapor per mass of dry air.
- Relative Humidity: Ratio of current water vapor to maximum capacity at the same temperature.
Dew Point
- Dew Point: Temperature at which air becomes saturated and water vapor condenses.
- Frost Point: Dew point at or below freezing, leading to frost formation.
- Fog: Formed when air cools enough to condense water vapor into tiny droplets.
- Types of Fog:
- Radiation Fog: Forms when the ground cools and lowers air temperature.
- Advection Fog: Warm, moist air moves over cooler surfaces.
- Upslope Fog: Moist air is lifted to cooler altitudes leading to condensation.