Humidity and Adiabatic Processes

These flashcards cover essential vocabulary and concepts related to humidity and adiabatic processes in the atmosphere, as outlined in the lecture notes.

Mixing Ratio

The actual amount of water vapor in the air, expressed as grams of water vapor per kilogram of dry air (g/kg).

Specific Humidity

Similar to mixing ratio, but describes grams of water vapor per kilogram of air, including water vapor.

Absolute Humidity

Mass of water vapor in a given volume of air, expressed in grams of water vapor per cubic meter (g/m³).

Relative Humidity (RH)

A ratio that compares the actual amount of water vapor in the air to the maximum amount of water vapor that can be in the air at a certain temperature, expressed as a percentage.

Dew Point Temperature

The temperature at which a parcel of air reaches 100% relative humidity; the mixing ratio equals the saturation mixing ratio.

Dry Adiabatic Rate (DAR)

The rate at which unsaturated air cools, approximately 10°C per 1000 meters.

Saturated Adiabatic Rate (SAR)

The rate at which saturated air cools, approximately 6°C per 1000 meters, though it can vary.

Lifting Condensation Level (LCL)

The height at which rising air cools to its dew point and begins to condense.

Stability of Air

Determined by the relative temperature of a parcel of air compared to surrounding air; unstable air rises on its own.

Environmental Lapse Rate (ELR)

The temperature change in the atmosphere with altitude, averaging about 6.5°C per 1000 meters.

Occluded Front

Formed when a cold front catches up with a warm front, lifting warm air off the ground.

Cold Front

A boundary where cold air is advancing under warm air.

Warm Front

A boundary where warm air is advancing over cold air.

Conditional Instability

Situations where rising air is stable initially but becomes unstable after condensation, due to the release of latent heat.

Adiabatic Cooling

Cooling of rising air as it expands due to lower pressure without heat exchange with the environment.