High-pressure area are alternatively referred to as anticyclones. On English-language weather maps, high-pressure centers are identified by the letter H in English, within the isobar with the highest pressure value. On constant pressure upper level charts, it is located within the highest height line contour. Highs are frequently associated with light winds at the surface and subsidence through the lower portion of the troposphere. In general, subsidence will dry out an air mass by adiabatic, or compressional, heating. Thus, high pressure typically brings clear skies. During the day, since no clouds are present to reflect sunlight, there is more incoming shortwave solar
High-pressure steam locomotive sealed ultra-high-pressure circuit that simply transferred heat to a high-pressure circuit, by means of heating coils inside a high-pressure boiler. If this latter was fed with ordinary water, scale could form on the outside of the heating coils, but it could not cause overheating because the ultra-HP tubes were quite capable of withstanding their internal steam temperature, though not the firebox flame temperature. The sealed ultra-high-pressure circuit ran at between , depending on the rate of firing. The HP boiler worked at approx , and the low-pressure boiler at . The UHP and HP boilers were of a water tube