Altitude significantly influences atmospheric pressure due to the decrease in air density with elevation. At higher altitudes, the weight of the air above decreases, resulting in lower pressure. This decrease in pressure affects various physical and biological processes, including breathing and weather patterns. For example, as one ascends a mountain, the thinner air can lead to altitude sickness for some individuals due to lower oxygen availability. The correlation between altitude and pressure is important in fields like meteorology and aviation, as understanding it aids in predicting weather changes and ensuring flight safety.