A
weather or
sounding balloon is a
balloonA balloon is an inflatable flexible bag filled with a type of gas, such as helium, hydrogen, nitrous oxide or air. Modern balloons can be made from materials such as rubber, latex, polychloroprene, or a nylon fabric, while some early balloons were sometimes made of dried animal bladders...
(specifically a type of
high altitude balloonHigh altitude balloons are unmanned balloons, usually filled with helium or hydrogen that are released into the stratosphere, generally reaching between 60,000 and 120,000 feet ....
) which carries instruments aloft to send back information on
atmospheric pressureAtmospheric pressure is defined as the force per unit area exerted against a surface by the weight of air above that surface at any given point in the Earth's atmosphere. In most circumstances atmospheric pressure is closely approximated by the hydrostatic pressure caused by the weight of air above...
,
temperatureIn physics, temperature is a physical property of a system that underlies the common notions of hot and cold; something that feels hotter generally has the higher temperature. Temperature is one of the principal parameters of thermodynamics...
, and
humidityHumidity is the amount of water vapour in the air. In daily language the term "humidity" is normally taken to mean relative humidity. Relative humidity is defined as the ratio of the partial pressure of water vapour in a parcel of air to the saturated vapour pressure of water vapour at a prescribed...
by means of a small, expendable measuring device called a
radiosondeA radiosonde is a unit for use in weather balloons that measures various atmospheric parameters and transmits them to a fixed receiver. Radiosondes may operate at a radio frequency of 403 MHz or 1680 MHz and both types may be adjusted slightly higher or lower as required...
. To obtain
windWind is the flow of air or other gases that compose an atmosphere . On Earth, wind consists of the bulk movement of air...
data, they can be tracked by
radarRadar is an object detection system that uses electromagnetic waves to identify the range, altitude, direction, or speed of both moving and fixed objects such as aircraft, ships, motor vehicles, weather formations, and terrain. The term RADAR was coined in 1941 as an acronym for RAdio Detection And...
,
radio direction findingDirection finding refers to the establishment of the direction from which a received signal was transmitted. This can refer to radio or other forms of wireless communication...
, or navigation systems (such as the satellite based
Global Positioning System The Global Positioning System is a U.S. space-based global navigation satellite system. It provides reliable positioning, navigation, and timing services to worldwide users on a continuous basis in all weather, day and night, anywhere on or near the Earth.GPS is made up of three parts: between 24...
also known as a GPS).
The balloon itself produces the
liftA lifting gas is required for aerostats to create buoyancy. Its density is lower than that of air . Only certain lighter than air gases are suitable as lifting gases.- Ammonia :...
, and is usually made of a highly flexible latex material (though
ChloropreneChloroprene is the common name for the organic compound 2-chloro-1,3-butadiene, which has the formula CH2=CCl-CH=CH2. This colorless liquid is the monomer for the production of the polymer polychloroprene, a type of synthetic rubber...
may also be used).
A
weather or
sounding balloon is a
balloonA balloon is an inflatable flexible bag filled with a type of gas, such as helium, hydrogen, nitrous oxide or air. Modern balloons can be made from materials such as rubber, latex, polychloroprene, or a nylon fabric, while some early balloons were sometimes made of dried animal bladders...
(specifically a type of
high altitude balloonHigh altitude balloons are unmanned balloons, usually filled with helium or hydrogen that are released into the stratosphere, generally reaching between 60,000 and 120,000 feet ....
) which carries instruments aloft to send back information on
atmospheric pressureAtmospheric pressure is defined as the force per unit area exerted against a surface by the weight of air above that surface at any given point in the Earth's atmosphere. In most circumstances atmospheric pressure is closely approximated by the hydrostatic pressure caused by the weight of air above...
,
temperatureIn physics, temperature is a physical property of a system that underlies the common notions of hot and cold; something that feels hotter generally has the higher temperature. Temperature is one of the principal parameters of thermodynamics...
, and
humidityHumidity is the amount of water vapour in the air. In daily language the term "humidity" is normally taken to mean relative humidity. Relative humidity is defined as the ratio of the partial pressure of water vapour in a parcel of air to the saturated vapour pressure of water vapour at a prescribed...
by means of a small, expendable measuring device called a
radiosondeA radiosonde is a unit for use in weather balloons that measures various atmospheric parameters and transmits them to a fixed receiver. Radiosondes may operate at a radio frequency of 403 MHz or 1680 MHz and both types may be adjusted slightly higher or lower as required...
. To obtain
windWind is the flow of air or other gases that compose an atmosphere . On Earth, wind consists of the bulk movement of air...
data, they can be tracked by
radarRadar is an object detection system that uses electromagnetic waves to identify the range, altitude, direction, or speed of both moving and fixed objects such as aircraft, ships, motor vehicles, weather formations, and terrain. The term RADAR was coined in 1941 as an acronym for RAdio Detection And...
,
radio direction findingDirection finding refers to the establishment of the direction from which a received signal was transmitted. This can refer to radio or other forms of wireless communication...
, or navigation systems (such as the satellite based
Global Positioning System The Global Positioning System is a U.S. space-based global navigation satellite system. It provides reliable positioning, navigation, and timing services to worldwide users on a continuous basis in all weather, day and night, anywhere on or near the Earth.GPS is made up of three parts: between 24...
also known as a GPS).
Materials and equipment
The balloon itself produces the
liftA lifting gas is required for aerostats to create buoyancy. Its density is lower than that of air . Only certain lighter than air gases are suitable as lifting gases.- Ammonia :...
, and is usually made of a highly flexible latex material (though
ChloropreneChloroprene is the common name for the organic compound 2-chloro-1,3-butadiene, which has the formula CH2=CCl-CH=CH2. This colorless liquid is the monomer for the production of the polymer polychloroprene, a type of synthetic rubber...
may also be used). The unit that performs the actual measurements and
radio transmissionsIn telecommunications, transmission is the process of sending, propagating and receiving an analogue or digital information signal over a physical point-to-point or point-to-multipoint transmission medium, either wired or wireless...
hangs at the lower end of the string, and is called a
radiosondeA radiosonde is a unit for use in weather balloons that measures various atmospheric parameters and transmits them to a fixed receiver. Radiosondes may operate at a radio frequency of 403 MHz or 1680 MHz and both types may be adjusted slightly higher or lower as required...
. Specialized radiosondes are used for measuring particular parameters, such as determining the
ozoneThe ozone layer is a layer in Earth's atmosphere which contains relatively high concentrations of ozone . This layer absorbs 93-99% of the sun's high frequency ultraviolet light, which is potentially damaging to life on earth. Over 91% of the ozone in Earth's atmosphere is present here...
concentration.
The balloon is usually filled with
hydrogenHydrogen is the chemical element with atomic number 1. It is represented by the symbol H. At standard temperature and pressure, hydrogen is a colorless, odorless, nonmetallic, tasteless, highly flammable diatomic gas with the molecular formula H
2...
due to lower cost, though
heliumHelium is the chemical element with atomic number 2, and is represented by the symbol He. It is a colorless, odorless, tasteless, non-toxic, inert monatomic gas that heads the noble gas group in the periodic table...
can be used as a substitute. The ascent rate can be controlled by the amount of gas with which the balloon is filled. Weather balloons may reach altitudes of 40 km (25 miles) 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. Above that altitude
sounding rocketA sounding rocket, sometimes called a research rocket, is an instrument-carrying rocket designed to take measurements and perform scientific experiments during its sub-orbital flight. The origin of the term comes from nautical vocabulary, it refers to to sound, which means to throw a weighted...
s are used. After sounding rockets, satellites are used for even higher altitudes.
Major manufacturers of balloons are Zhuzhou Research & Design Institute of Rubber & Plastic (Brand: Hwoyee)[China],
TotexTotex Corporation is a Japanese manufacturer of meteorological balloons. The company began production of balloons in 1937.They currently produce three types of balloons:*TA is a rubber/latex balloon and was developed in 1940....
and Cosmopren of
Japanis an island country in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, People's Republic of China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
, Pawan Rubber Products (Pawan Exports) of
IndiaIndia, officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the south, the Arabian Sea on the west, and the Bay of Bengal...
,
KaysamKaysam Worldwide Inc. was a manufacturer of latex balloons, located in Totowa, New Jersey, USA. Kaysam has now changed their name to Kaymont....
(now Kaymont), and Scientific Sales, Inc. of the
U.S.The United States of America is a federal constitutional republic comprising fifty states and a federal district...
.
Weather balloons are sometimes cited as the cause for
unidentified flying objectUnidentified flying object is the popular term for any aerial phenomenon whose cause cannot be easily or immediately identified...
sightings, and are also used for
cluster ballooningCluster ballooning is an uncommon form of ballooning in which a single balloonist is attached by a harness to a cluster of relatively small helium-inflated rubber balloons....
.
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
computer modelsNumerical weather prediction uses current weather conditions as input into mathematical models of the atmosphere to predict the weather. While the first efforts to accomplish this were done in the 1920s, it wasn't until the advent of the computer that it was feasible to do in real-time...
for
weather forecastingWeather forecasting is the application of science and technology to predict the state of the atmosphere for a future time and a given location. Human beings have attempted to predict the weather informally for millennia, and formally since at least the nineteenth century...
. About 800 locations around the globe do routine releases, twice daily, usually at 0000
UTCCoordinated Universal Time , ) is a time standard based on International Atomic Time with leap seconds added at irregular intervals to compensate for the Earth's slowing rotation...
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 ServiceThe National Weather Service , once known as the Weather Bureau, is one of the six scientific agencies that make up the National Oceanic and Atmospheric Administration of the United States government...
in the US typically launch balloons, and by international agreements almost all the data is shared with all nations.
Specialized uses also exist, such as for aviation interests, pollution monitoring, and research. Examples include pilot balloons (Pibal). Field research programs often use mobile launchers from land vehicles as well as ships and aircraft (usually
dropsondeA dropsonde is a weather reconnaissance device created by the National Center for Atmospheric Research , designed to be dropped from an aircraft at altitude to more accurately measure tropical storm conditions as the device falls to the ground...
s in this case).
See also
- High altitude balloon
High altitude balloons are unmanned balloons, usually filled with helium or hydrogen that are released into the stratosphere, generally reaching between 60,000 and 120,000 feet ....
- Radiosonde
A radiosonde is a unit for use in weather balloons that measures various atmospheric parameters and transmits them to a fixed receiver. Radiosondes may operate at a radio frequency of 403 MHz or 1680 MHz and both types may be adjusted slightly higher or lower as required...
- SCR-658 radar
The SCR-658 radar was developed in conjunction with the SCR-268 radar. It was preceded by the SCR-258. Its primary purpose was to track weather balloons. Prior to this it was only possible to track weather balloons with a theodolite, causing difficulty with visual tracking in poor weather conditions...
- Timeline of hydrogen technologies
Timeline of hydrogen technologies A timeline of the history of hydrogen technology.-1600s:* 1625 - First description of hydrogen by Johann Baptista van Helmont...
External links