As water evaporates from a surface, it removes heat and cools the surface. The lowest temperature to which a surface can be cooled by the evaporation of water is known as the wet-bulb temperature. This temperature is measured using a thermometer exposed to air but shielded from direct sunlight and is used to assess psychological comfort in a thermal environment.
Cooler air holds less moisture, so cooling air at a specific temperature can cause it to reach full saturation with moisture. This point at which air becomes fully saturated with moisture is called the dew point. Scientists introduced the ultraviolet index in 1992, which was later adopted by the World Health Organization and the World Meteorological Organization in 1994. The UV index is measured on a scale and indicates the level of solar radiation, with higher values posing risks such as sunburn and DNA damage.
The weather phenomenon shown above is La Niña, where a band of cool water spreads from east to west across the equatorial Pacific Ocean. However, global warming also plays a role in shaping weather patterns, including producing wetter cyclones due to changes in relative humidity caused by warmer temperatures. This relationship between temperature and moisture content is an important factor to consider when studying weather patterns and their potential impacts on our environment.
