Dines' compensation, or Dines compensation principle, is a

rule of thumb In English, the phrase ''rule of thumb'' refers to an approximate method for doing something, based on practical experience rather than theory. This usage of the phrase can be traced back to the 17th century and has been associated with various t ...

devised by English

meteorologist A meteorologist is a scientist who studies and works in the field of meteorology aiming to understand or predict Earth's atmospheric phenomena including the weather. Those who study meteorological phenomena are meteorologists in research, while t ...

William Henry Dines William Henry Dines BA FRS (5 August 1855 – 24 December 1927) was an English meteorologist. Dines was born in London, the son of George Dines, also a meteorologist. He was educated at Woodcote House School, Windlesham, and afterwards entere ...

which states that ''winds converging on a given column of air at one altitude tends to be balanced by winds diverging at another altitude'', and vice versa. As an example, the air under a thunderstorm rushes in at ground level, rises up through the

cumulonimbus Cumulonimbus (from Latin ''cumulus'', "heaped" and ''nimbus'', "rainstorm") is a dense, towering vertical cloud, typically forming from water vapor condensing in the lower troposphere that builds upward carried by powerful Buoyancy, buoyant air ...

cloud, and then disperses at the top of the cloud so there is a balancing of converging and diverging air flows and no net increase in air molecules above a given location. Dines compensation is a demonstration of

conservation of mass In physics and chemistry, the law of conservation of mass or principle of mass conservation states that for any system closed to all transfers of matter and energy, the mass of the system must remain constant over time, as the system's mass can ...

under the weak constraint that the height of the atmosphere is approximately the same anywhere on Earth. Mathematically it may be stated that the sign of the horizontal divergence changes at least once in any given column of air. A corollary is that rising air at any given point in the atmosphere tends to be balanced by sinking or subsiding air elsewhere. This is a salient feature of mesoscale

atmospheric circulation Atmospheric circulation is the large-scale movement of air and together with ocean circulation is the means by which thermal energy is redistributed on the surface of the Earth. The Earth's atmospheric circulation varies from year to year, but t ...

(i.e.

supercell A supercell is a thunderstorm characterized by the presence of a mesocyclone: a deep, persistently rotating updraft. Due to this, these storms are sometimes referred to as rotating thunderstorms. Of the four classifications of thunderstorms (s ...

s) and in macroscale and mesoscale

tropical The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in the Southern Hemisphere at S. The tropics are also referred to ...

circulations. For instance, it is not uncommon to see high altitude

anticyclonic An anticyclone is a weather phenomenon defined as a large-scale circulation of winds around a central region of high atmospheric pressure, clockwise in the Northern Hemisphere and counterclockwise in the Southern Hemisphere as viewed from abov ...

cirrus Cirrus may refer to: Science *Cirrus (biology), any of various thin, thread-like structures on the body of an animal *Cirrus (botany), a tendril *Infrared cirrus, in astronomy, filamentary structures seen in infrared light *Cirrus cloud, a type ...

outflow from a

hurricane A tropical cyclone is a rapidly rotating storm system characterized by a low-pressure center, a closed low-level atmospheric circulation, strong winds, and a spiral arrangement of thunderstorms that produce heavy rain and squalls. Depend ...

in visible satellite imagery which is compensating for the inbound winds at sea level. Dines compensation is useful in

weather forecasting Weather forecasting is the application of science and technology forecasting, to predict the conditions of the Earth's atmosphere, atmosphere for a given location and time. People have attempted to predict the weather informally for millennia a ...

to connect the formation and movement of ground-level high and low pressure zones with wind phenomenon in the upper

troposphere The troposphere is the first and lowest layer of the atmosphere of the Earth, and contains 75% of the total mass of the planetary atmosphere, 99% of the total mass of water vapour and aerosols, and is where most weather phenomena occur. From ...

such as

Rossby waves Rossby waves, also known as planetary waves, are a type of inertial wave naturally occurring in rotating fluids. They were first identified by Sweden-born American meteorologist Carl-Gustaf Arvid Rossby. They are observed in the atmospheres and ...

and

jet streams Jet streams are fast flowing, narrow, meandering thermal wind, air currents in the Atmosphere of Earth, atmospheres of some planets, including Earth. On Earth, the main jet streams are located near the altitude of the tropopause and are west ...

. In general Dines compensation ties together vertical and horizontal air movements in the atmosphere.

References

{{Reflist Atmospheric dynamics