A weather balloon, also known as sounding balloon, is a

balloon A balloon is a flexible bag that can be inflated with a gas, such as helium, hydrogen, nitrous oxide, oxygen, and air. For special tasks, balloons can be filled with smoke, liquid water, granular media (e.g. sand, flour or rice), or light so ...

(specifically a type of

high-altitude balloon High-altitude balloons are crewed or uncrewed balloons, usually filled with helium or hydrogen, that are released into the stratosphere, generally attaining between above sea level. In 2002, a balloon named BU60-1 reached a record altitude of . ...

) that carries instruments aloft to send back information on

atmospheric pressure Atmospheric pressure, also known as barometric pressure (after the barometer), is the pressure within the atmosphere of Earth. The standard atmosphere (symbol: atm) is a unit of pressure defined as , which is equivalent to 1013.25 millibars, ...

temperature Temperature is a physical quantity that expresses quantitatively the perceptions of hotness and coldness. Temperature is measurement, measured with a thermometer. Thermometers are calibrated in various Conversion of units of temperature, temp ...

humidity Humidity is the concentration of water vapor present in the air. Water vapor, the gaseous state of water, is generally invisible to the human eye. Humidity indicates the likelihood for precipitation, dew, or fog to be present. Humidity dep ...

and

wind speed In meteorology, wind speed, or wind flow speed, is a fundamental atmospheric quantity caused by air moving from high to low pressure, usually due to changes in temperature. Wind speed is now commonly measured with an anemometer. Wind speed ...

by means of a small, expendable measuring device called a

radiosonde A radiosonde is a battery-powered telemetry instrument carried into the atmosphere usually by a weather balloon that measures various atmospheric parameters and transmits them by radio to a ground receiver. Modern radiosondes measure or calcula ...

. To obtain

wind Wind is the natural movement of air or other gases relative to a planet's surface. Winds occur on a range of scales, from thunderstorm flows lasting tens of minutes, to local breezes generated by heating of land surfaces and lasting a few ho ...

data, they can be tracked by

radar Radar is a detection system that uses radio waves to determine the distance ('' ranging''), angle, and radial velocity of objects relative to the site. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, we ...

, radio

direction finding Direction finding (DF), or radio direction finding (RDF), isin accordance with International Telecommunication Union (ITU)defined as radio location that uses the reception of radio waves to determine the direction in which a radio stati ...

, or navigation systems (such as the satellite-based

Global Positioning System The Global Positioning System (GPS), originally Navstar GPS, is a satellite-based radionavigation system owned by the United States government and operated by the United States Space Force. It is one of the global navigation satellite sy ...

, GPS). Balloons meant to stay at a constant altitude for long periods of time are known as ''transosondes''. Weather balloons that do not carry an instrument pack are used to determine upper-level winds and the height of cloud layers. For such balloons, a

theodolite A theodolite () is a precision optical instrument for measuring angles between designated visible points in the horizontal and vertical planes. The traditional use has been for land surveying, but it is also used extensively for building an ...

total station A total station (TS) or total station theodolite (TST) is an electronic/optical instrument used for surveying and building construction. It is an electronic transit theodolite integrated with electronic distance measurement (EDM) to measure ...

is used to track the balloon's

azimuth An azimuth (; from ar, اَلسُّمُوت, as-sumūt, the directions) is an angular measurement in a spherical coordinate system. More specifically, it is the horizontal angle from a cardinal direction, most commonly north. Mathematical ...

and elevation, which are then converted to estimated wind speed and direction and/or cloud height, as applicable. Weather balloons are launched around the world for observations used to diagnose current conditions as well as by human forecasters and

computer models Computer simulation is the process of mathematical modelling, performed on a computer, which is designed to predict the behaviour of, or the outcome of, a real-world or physical system. The reliability of some mathematical models can be deter ...

for

weather forecasting Weather forecasting is the application of science and technology to predict the conditions of the atmosphere for a given location and time. People have attempted to predict the weather informally for millennia and formally since the 19th cent ...

. Between 900 and 1,300 locations around the globe do routine releases, two or four times daily.Radiosonde
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History

One of the first persons to use weather balloons was

Léon Teisserenc de Bort Léon Philippe Teisserenc de Bort (5 November 1855 in Paris, France – 2 January 1913 in Cannes, France) was a French meteorologist and a pioneer in the field of aerology. Together with Richard Assmann (1845-1918), he is credited as co-discovere ...

, the French

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 ...

. Starting in 1896 he launched hundreds of weather balloons from his observatory in

Trappes Trappes () is a Communes of France, commune in the Yvelines departments of France, department, region of Île-de-France, north-central France. It is a banlieue located in the western suburbs of Paris, from the Kilometre Zero, center of Paris, i ...

, France. These experiments led to his discovery of the

tropopause The tropopause is the atmospheric boundary that demarcates the troposphere from the stratosphere; which are two of the five layers of the atmosphere of Earth. The tropopause is a thermodynamic gradient-stratification layer, that marks the end of ...

and stratosphere. Transosondes, weather balloons with instrumentation meant to stay at a constant altitude for long periods of time to help diagnose radioactive debris from atomic fallout, were experimented with in 1958. The drone technology boom has led to the development of

weather drone A weather drone, or weather-sensing uncrewed aerial vehicle (UAV), – is a remotely piloted aircraft weighing less than 25 kg and carrying sensors that collect thermodynamic and kinematic data from the mid and lower atmosphere (e.g. up to 6 ...

s since the late 1990s. These may begin to replace balloons as a more specific means for carrying radiosondes.

Materials and equipment

The balloon itself produces the

lift Lift or LIFT may refer to: Physical devices * Elevator, or lift, a device used for raising and lowering people or goods ** Paternoster lift, a type of lift using a continuous chain of cars which do not stop ** Patient lift, or Hoyer lift, mobil ...

, and is usually made of a highly flexible

latex Latex is an emulsion (stable dispersion) of polymer microparticles in water. Latexes are found in nature, but synthetic latexes are common as well. In nature, latex is found as a milky fluid found in 10% of all flowering plants (angiosperms ...

material, though

Chloroprene Chloroprene is the common name for 2-chlorobuta-1,3-diene (IUPAC name) with the chemical formula CH2=CCl−CH=CH2. Chloroprene is a colorless volatile liquid, almost exclusively used as a monomer for the production of the polymer polychloroprene ...

may also be used. The unit that performs the actual measurements and radio transmissions hangs at the lower end of the string, and is called a

. Specialized radiosondes are used for measuring particular parameters, such as determining the

ozone Ozone (), or trioxygen, is an inorganic molecule with the chemical formula . It is a pale blue gas with a distinctively pungent smell. It is an allotrope of oxygen that is much less stable than the diatomic allotrope , breaking down in the lo ...

concentration. The balloon is usually filled with

hydrogen Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic ...

due to lower cost, though

helium Helium (from el, ἥλιος, helios, lit=sun) is a chemical element with the symbol He and atomic number 2. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas and the first in the noble gas group in the periodic table. ...

can also be used. The ascent rate can be controlled by the amount of gas with which the balloon is filled. Weather balloons may reach altitudes of or more, limited by diminishing pressures causing the balloon to expand to such a degree (typically by a 100:1 factor) that it disintegrates. In this instance the instrument package is usually lost, although a parachute may be used to help in allowing retrieval of the instrument. Above that altitude sounding rockets are used, and for even higher altitudes satellites are used.

Launch time, location, and uses

Weather balloons are launched around the world for observations used to diagnose current conditions as well as by human forecasters and

for

. Between 900 and 1,300 locations around the globe do routine releases, two or four times daily, usually at 0000 UTC and 1200 UTC. Some facilities will also do occasional supplementary special releases when meteorologists determine there is a need for additional data between the 12-hour routine launches in which time much can change in the atmosphere. Military and civilian government meteorological agencies such as the

National Weather Service The National Weather Service (NWS) is an agency of the United States federal government that is tasked with providing weather forecasts, warnings of hazardous weather, and other weather-related products to organizations and the public for the ...

in the US typically launch balloons, and by international agreements almost all the data are shared with all nations. Specialized uses also exist, such as for aviation interests, pollution monitoring, photography or videography and research. Examples include

pilot balloon A ceiling balloon also called a pilot balloon or pibal, is used by meteorologists to determine the height of the base of clouds above ground level during daylight hours. In the past, and sometimes today, a theodolite was used to track the ba ...

s (Pibal). Field research programs often use mobile launchers from land vehicles as well as ships and aircraft (usually

dropsonde A dropsonde is an expendable weather reconnaissance device created by the National Center for Atmospheric Research (NCAR), designed to be dropped from an aircraft at altitude over water to measure (and therefore track) storm conditions as the devi ...

s in this case). In recent years weather balloons have also been used for scattering human ashes at high-altitude. The weather balloon was also used to create the fictional entity 'Rover' during production of the 1960s TV series ''

The Prisoner ''The Prisoner'' is a 1967 British television series about an unnamed British intelligence agent who is abducted and imprisoned in a mysterious coastal village, where his captors designate him as Number Six and try to find out why he abruptl ...

'' in Portmeirion, Gwynedd, North Wales, UK in September 1966. This was retained in further scenes shot at MGM Borehamwood UK during 1966–67.

References

External links

Atmospheric Soundings for Canada and the United States
– University of Wyoming

– University of Hawaii

– NSSL

* ttps://web.archive.org/web/20070704045456/http://www.ua.nws.noaa.gov/photo.htm Kites and Balloons– NOAA Photo Library
NASA Balloon Program Office
– Wallops Flight Facility, Virginia
National Science Digital Library: Weather Balloons
– Lesson plan for middle school
Pilot Balloon Observation Theodolites
– Martin Brenner, CSULB

– Historical recompilation project on the use of stratospheric balloons in the scientific research, the military field and the aerospace activity

{{Earth-based meteorological observation Balloons (aeronautics) Meteorological instrumentation and equipment Scientific observation Unmanned aerial vehicles French inventions Atmospheric sounding

History

Materials and equipment

Launch time, location, and uses

See also

References

External links