Acid rain is mainly caused by atmospheric pollution from sulfur dioxide, which forms sulfuric acid when dissolved in water. Sulfur dioxide is emitted during the burning of fossil fuels. In recent years, the percentage of nitric acid in acid rain has been increasing as a result of reducing sulfur dioxide emissions, but sulfuric acid is still the main culprit. ¹⁾

The cyclone eye is the central area of a tropical cyclone. In the eye of the cyclone, the winds are weak or even quiet. This area also lacks precipitation but has an elevated temperature and very low pressure (below 960 hPa). In its area, the sky is almost cloudless. Around the eye of the cyclone, thanks to a very strong ascending current, huge clouds develop vertically. ²⁾

St. Elmo's fires are electrical discharges on various surfaces, especially the edges of objects, occurring during weather that precedes a storm. ³⁾

Clouds of the volutus species take the form of elongated, horizontally arranged cylinders, often rotating slowly around a horizontal axis. They are relatively rare, and the species itself was not officially added to the cloud classification until recently. ⁴⁾

The clouds on Venus are made of sulfuric acid droplets of very high density, resulting in a huge greenhouse effect. The greenhouse effect has also been found on an unnamed moon of Mars and Saturn's moon Titan. ⁵⁾