Lab 5 & Lab 6

Mixing Ratio: Actual amount of water vapor in the air, expressed in g/kg (grams of water vapor per kilogram of dry air).

Relative Humidity (RH): Ratio of the actual amount of water vapor in the air to the maximum capacity at a given temperature.
- Formula: ( RH = \frac{\text{Actual Water Vapor Content}}{\text{Water Vapor Capacity}} )
Degree of Saturation: Expressed as a percentage.
- Example: 50% RH means air contains half the needed water vapor for saturation.
- 100% RH indicates that the air is saturated.
Saturation Mixing Ratio: Water vapor capacity of the air at a given temperature.

Water vapor capacity is temperature-dependent:
- Increases with temperature.
- Decreases as temperature declines.
Changes in temperature affect Relative Humidity:
- Decrease in temperature leads to an increase in RH.

Formula: ( RH = \frac{\text{Mixing Ratio}}{\text{Saturation Mixing Ratio}} \times 100 )
Example Calculation:
- Actual Water Vapor = 13.5 g/kg
- Capacity = 22.5 g/kg
- Calculation gives 60% RH.

Dew Point: Temperature at which air achieves 100% RH; actual vapor content equals capacity.

Adiabatic Process: Air parcels expand or compress without heat exchange.
- Rising air expands and cools adiabatically; descending air compresses and warms adiabatically.

Dry Adiabatic Rate (DAR): Unsaturated air cools at approximately 10°C per 1,000 meters (5.5°F per 1,000 feet).
Saturated Adiabatic Rate (SAR): Saturated air cools at a slower rate of about 6°C per 1,000 meters (3.3°F per 1,000 feet)

LCL: The altitude where rising air cools to its Dew Point, leading to condensation and cloud formation.

Latent Heat Release: Occurs during condensation, affecting temperature rates during rising saturated air.
Evaporation cools the air; condensation releases heat.

As air rises (e.g., crossing a mountain), temperatures decrease due to cooling at DAR until reaching LCL; then cooling continues more slowly at SAR due to latent heat release.