Abstract

Visibility data are fundamental meteorological data widely used in many fields such as climate change, atmospheric radiation, atmospheric pollution, and environmental health. Calculating the average visibility is typically the first step when using visibility data. However, this study proves that the algorithm previously used to calculate average visibility is incorrect, leading to a non-negligible error in average visibility data. Moreover, the use of this incorrect algorithm not only artificially reduces the reliability of visibility data, but also affects the credibility and even the correctness of the conclusions reached in previous studies using visibility data. Therefore, we present the correct algorithm for average visibility, which should be applied to both future and previous research to significantly increase the reliability and application scope of visibility data.