Weather Balloon
A weather balloon serves for the determination of the upper atmospheric conditions, gathering data that it sends back to the basis by means of a radio transmitter. There are two main ways in which a weather balloon can get the temperature, the air pressure and the wind specificity: it can either record and transmit data as it ascends, or it can start measuring only when it reaches a predetermined altitude. Modern technology uses special radars, all sorts of sensors and complex satellite systems to determine weather conditions, and the use of a weather balloon is just a supplementary means of increasing the level of information.
Helium is the most widely used gas for the inflation of a weather balloon; its preference comes from the fact that it is less dense than air, which ensures a good buoyancy of the envelope. Several weather balloons types exist, each with a specific function. Thus, a pilot weather balloon is a smaller air craft that is followed visually when ascending; its main utility is that of providing information on the speed and the direction of the wind. Then, there is the ceiling weather balloon with multiple applications in determining the altitude of cloud basis. And last but not least, the most advanced model is the teardrop.
The teardrop weather balloon carries a radiosonde, which is the necessary equipment to measure temperature, air pressure and humidity levels at very high altitudes. Under the influence of the decreasing atmospheric pressure, the balloon inflates until it bursts; then, the gear aloft is parachuted down to be retrieved. When flying horizontally, a weather balloon can be monitored or tracked by satellites; it is horizontal sounding that creates the biggest challenges for investigations. Thus, only very advanced weather balloon models can remain intact at very low pressures and resist dire weather conditions in the external layers of the atmosphere.
The tetroon is the weather balloon used for horizontal sounding. The manufacturing techniques are very special, allowing the air craft to withstand the challenges of high-altitude flight. The triangular faces of this weather balloon have straight seals with a superior level of resistance as compared to the curved seals specific to traditional balloons. Tetroons are generally used to track low-level atmospheric currents allowing meteorologists to develop a better understanding of the formation of air turbulences, vertical air movement and pollution dispersion. The costs for such weather balloons are much higher, but the data retrieved this way surely make the price worth paying.