Final answer:
In terms of air mass, the symbols used by meteorologists on weather maps represent the pressure at a particular location.
Step-by-step explanation:
In terms of air mass, the symbols used by meteorologists on weather maps represent the pressure at a particular location. A high pressure system is denoted by the letter 'H', indicating that the air is sinking and generally associated with clear skies and fair weather. Conversely, a low pressure system is represented by the letter 'L', indicating that the air is rising and typically associated with cloudy and stormy conditions.