What do isobars on a weather map primarily indicate?

• A. Air pressure gradients and wind
• B. Temperature distribution
• C. Humidity levels
• D. Ocean depth

Answer: (A)

Isobars are lines of equal atmospheric pressure on a weather map. They show how pressure changes across an area: when the lines are close together, the pressure gradient is strong and the winds are typically stronger; when they’re spread apart, the gradient is weaker and winds are lighter. This pattern also helps identify high- and low-pressure systems, which drive wind directions and weather. Temperature, humidity, and ocean depth are represented by other data or maps, not by isobars, so the primary thing these lines indicate is the air pressure gradient and the associated potential wind strength.