High-pressure area to describe the weather systems generated by highs and lows were introduced in the mid-1800s, mostly by the British. The scientific theories which explain the general phenomena originated about two centuries earlier. The term cyclone was coined by Henry Piddington of the British East India Company to describe the devastating storm of December 1789 in Coringa, India. A cyclone forms around a low-pressure area. Anticyclone, the term for the kind of weather around a high-pressure area, was coined in 1877 by Francis Galton to indicate an area whose winds revolved in the opposite direction of a cyclone. In British English,
Atmospheric pressure Siberian High often attains a "sea-level pressure" above , with record highs close to . The lowest measurable "sea-level pressure" is found at the centers of tropical cyclones and tornadoes, with a record low of (see Atmospheric pressure records). "Surface pressure" is the atmospheric pressure at a location on Earth's surface (terrain and oceans). It is directly proportional to the mass of air over that location. For numerical reasons, atmospheric models such as general circulation models (GCMs) usually predict the nondimensional "logarithm of surface pressure". The average value of surface pressure on Earth is 985hPa. This is in contrast to