weather balloon

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weather balloon,

lighter-than-air craft without a propulsion system, lifted by inflation of one or more containers with a gas lighter than air or with heated air. During flight, altitude may be gained by discarding ballast (e.g.
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 used in the measurement and evaluation of mostly upper atmospheric conditions (see atmosphereatmosphere
[Gr.,=sphere of air], the mixture of gases surrounding a celestial body with sufficient gravity to maintain it. Although some details about the atmospheres of other planets and satellites are known, only the earth's atmosphere has been well studied, the science of
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). Information may be gathered during the vertical ascent of the balloon through the atmosphere or during its motions once it has reached a predetermined maximum altitude. Today, atmospheric information is most often gathered by height-finding radar, remote sensing by earth-orbiting or stationary satellites, and aircraft instruments, with weather balloons augmenting the data. Helium, which is less dense than air (see buoyancybuoyancy
, upward force exerted by a fluid on any body immersed in it. Buoyant force can be explained in terms of Archimedes' principle.
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), is usually used to inflate weather balloons. A pilot balloon is a small balloon (diameter c.1 m/39 in.) whose ascent is followed visually to obtain data for the computation of the speed and direction of winds at different altitudes. A smaller ceiling balloon is used to determine the altitude of cloud bases. A much larger, teardrop-shaped balloon is used to carry a radiosonderadiosonde
, group of instruments for simultaneous measurement and radio transmission of meteorological data, including temperature, pressure, and humidity of the atmosphere.
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 aloft. The balloon expands as it rises, usually reaching an altitude of at least 90,000 ft (27,400 m) before it bursts. A small parachute lowers the instruments to the ground. Teardrop-shaped balloons are also used for horizontal sounding of the atmosphere. Atmospheric pressure, temperature, and humidity information may be sent by radio from a balloon; monitoring of its movement provides information about winds at its flight level. Techniques also have been developed whereby many horizontal sounding balloons can be monitored by earth-orbiting satellitessatellite, artificial,
object constructed by humans and placed in orbit around the earth or other celestial body (see also space probe). The satellite is lifted from the earth's surface by a rocket and, once placed in orbit, maintains its motion without further rocket propulsion.
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 that relay information to earth-based stations. The tetroon is a tetrahedral balloon used for horizontal sounding. It was developed to withstand the extremely low pressures of high-altitude flight; the straight seals joining its four triangular faces are stronger than the curved seals of the more traditionally shaped balloons. Tetroons have been used extensively in tracing low-level atmospheric currents by following their movement with radar; they have thus increased the meteorologist's understanding of atmospheric turbulence, low-level vertical motions, and air pollution dispersion.
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References in periodicals archive ?
Currently, meteorological observations are conducted by radiosonde, a weather instrument that records meteorological data, typically released into the atmosphere with a weather balloon. However, due to hostile conditions experienced in the Arctic and the limited reach of the low-pressure system, the number, and frequency of these observations are limited.
The military explained that what crashed was a weather balloon, and it promptly swept away all or the debris left behind.
Did you ever wonder what happens when a rubber weather balloon reaches maximum altitude and bursts?
The only exception to the rule is in the case of weather balloons deployed by the airport bureau of the Indian Meteorological Department ( IMD), which sets these instruments to transmit weather- related data.
Google is working on a similar system with its Project Loon, which uses high-altitude weather balloons to provide connections.
According to the company, the approved patent embodies 48 specific claims which are applications-oriented, focusing on the practical aspects of controlling the aluminum powder-water reaction in its cartridge-based hydrogen generation system used in feeding fuel cells for backup power and filling weather balloons.
The previous research team had also launched weather balloons from a nearby airfield to calculate vertical profiles of prevailing wind speed and direction that influenced long-distance insect flights.
The new sensors, called WVSS-II, were manufactured by Spectra-Sensors and will measure water vapor hundreds of times during flight, replacing the twice-a-day method of weather balloons.
Every 12 hours, the National Oceanic and Atmospheric Administration (NOAA) launches weather balloons from approximately 70 locations across the US.
Using weather balloons from the United States, an iPhone, battery, GPS trackers and GoPro cameras - Nicholas successfully launched and returned the toys into space.
they are specially constructed for use in super-pressure balloons, which are longer-lasting than weather balloons because they can withstand higher pressure from the air inside when the balloons reach float altitude.