Aerology (pronounced a-erology) (from Greek: άέριος (aerios) "in the air, high"[1] and -logy), also known as high-altitude meteorology, is the branch of meteorology that deals with the study of the higher layers of the Earth's atmosphere (stratosphere, mesosphere, and thermosphere). The term aerology was coined by Wladimir Köppen in 1906.
Aerology, a branch of meteorology, monitors, explores, and documents the atmosphere using balloons (balloon probes), aircraft, radiosondes, rockets, and weather satellites, as well as ground-based radar (wind profilers), lidar, and microwave radar. All of these meteorological instruments record atmospheric parameters and transmit them via radio. Without continuous three-dimensional exploration and documentation of the current state of the atmosphere, especially the troposphere, neither effective aviation advice nor a fundamental understanding and forecast of the weather would be possible.
Therefore, the international community of states - the countries united in the WMO - continues to make great efforts to close the aerological information gaps worldwide by expanding modern aerological observation systems and evaluation strategies and thus to optimise meteorological advice and forecasts.
adiosonde
Hydrogen balloon with reflector
A radiosonde is used in meteorology and aerology to measure parameters of the Earth's atmosphere up to altitudes of approximately 20 km to 30 km (stratosphere). It is carried by a weather balloon and transmits measured values such as air temperature and its gradient, as well as humidity, to the ground station via radio data transmission. For probes with integrated GPS receivers, the probe's position is also transmitted. In some models, altitude is determined by continuous measurement of air pressure and GPS.
Balloon-borne probes are also used in other fields (see Balloon probe (measuring instrument), some of which reach even greater altitudes. The altitude record for radiosondes is approximately 39 km or 2.5 hPa (German Weather Service).
Definition]
A radiosonde or radiosonde (English radiosonde) is – as defined by the International Telecommunication Union (ITU) in the Radio Regulation[1] – an automatic radio transmitter of the meteorological radio service, which is generally carried in an aircraft, a free balloon, on a parachute or a kite and which transmits meteorological characteristics.
Story
Since the early 1890s, unmanned weather balloons, so-called recording balloons, carried self-recording measuring instruments into the atmosphere. Compared to manned balloon flights, these had a significant cost advantage. Furthermore, they allowed altitudes to be reached that were inaccessible to humans in an open basket, even with the aid of oxygen. However, the measured values could only be read with a time delay, and only if the instrument had returned to the ground and was found. One of the pioneers of atmospheric sounding with weather balloons was the German meteorologist Hugo Hergesell. As head of the International Commission for Scientific Aeronautics, he called for the construction of lightweight balloon-compatible instruments. Recognizing the potential of wireless telegraphy early on, he attempted to transmit recordings from recording balloon instruments by radio as early as 1908, but failed due to the lack of technical capabilities. The term "radiosonde" goes back to Hergesell.
In 1917, Max Robitzsch and Friedrich Herath (1889–1974) in Germany and Pierre Idrac (1885–1935) in France succeeded in transmitting measurements from instruments attached to weather kites to the ground via the kite wire. However, kites could not reach the altitudes achievable by weather balloons, and they could not be used in all weather conditions.
In 1921, Paul Duckert (1900–1966) began working on the development of the radiosonde at the Lindenberg Aeronautical Observatory, which was now headed by Hergesell. The first step was the dual tracking of a radio transmitter attached to a balloon in 1926 to determine its trajectory and speed. Similar experiments were also conducted by William Blair in the United States. By the end of the 1920s, several meteorologists were working with the first prototypes of radiosondes.
On January 7, 1929, Robert Bureau (1892–1965) in Trappes was the first to successfully receive signals from a radiosonde transmitting temperature values from the free atmosphere. In the spring of the same year, he added a barometer to the probe. However, the Soviet meteorologist Pavel Molchanov (1893–1941) is often credited as the inventor of the radiosonde. His radiosonde, successfully launched for the first time on January 30, 1930, became the standard for future developments. The probe measured temperature and pressure and transmitted the values coded as Morse code to the receiver. On May 22, 1930, Duckert followed suit with an independently developed probe that could measure temperature, pressure, and humidity. The probe transmitted measurements until the balloon burst at an altitude of over 15 km.
During the Arctic voyage of the Zeppelin LZ 127, Molchanov launched several radiosondes in July 1931. The new technology was used extensively and systematically during the International Polar Year of 1932/33. Vilho Väisälä, a Finn who launched his first radiosonde on December 30, 1931, began commercial production in 1936.
The radiosonde was further developed in 1942 by Josef Graw from Berlin. The conversion of the measured values into Morse code in the Graw probe occurs when the pointers of the measuring instruments scan a pattern of conductive material applied to a rotating roller, the Graw Morse code roller.[2]
The sensor and coding part of a radiosonde from the 1960s shown on the right shows
•Temperature sensor (top, bimetal)
•Pressure cell (left under the sheet metal angle)
•Time base (pocket watch movement, right outside)
•Encoder for temperature and humidity (red PVC cylinder with contact wire coil)
•Encoder for air pressure (hard paper bar with contact strip, right behind the cylinder)
The humidity sensor (hair hygrometer), the battery and the telemetry transmitter (UHF tube transmitter with a triode) are not visible in the picture.
Technology
Sensors on the radiosonde measure various parameters such as temperature, air pressure, and humidity as the balloon ascends and continuously transmit this data to the ground station via radio data link. Special ozonesondes can also measure ozone concentration. Data transmission is realized with a bandwidth of approximately 20 kHz in the frequency range from 400 MHz to 410 MHz; the exact frequency (channel) can be set before takeoff. There are also radiosondes that transmit data in the frequency range of 1.68 GHz.
The probes and especially the batteries are housed in a foam polystyrene casing for thermal insulation; on the outside there is only a wire antenna and sensors.
Today, single-use radiosondes are used, for which no finder's fee is paid. Potential finders are sometimes asked to dispose of the radiosonde, electronics, and batteries, via stickers affixed to the probes. A radiosonde ascent currently costs approximately €300 with a hydrogen-filled balloon and radiosonde, and approximately €400 with a 1.8 m³ helium filling.
Conventional radiosondes use a GPS receiver to determine their position, and the position data is transmitted cyclically via radio. This allows the wind direction of the upper-altitude winds to be determined. Alternatively, the position of a radiosonde can also be determined by radar. The probe carries a radar reflector made of cardboard coated with reflective foil due to its low weight, which reflects the radar pulse and thus allows conclusions to be drawn about the position. For example, MeteoSwiss and the Swiss Armed Forces do not use GPS receivers for their SRS400 weather probe.
To enable the probe to fly at all, a large, slightly inflated latex balloon filled with helium or hydrogen is attached to it. As altitude increases, the balloon becomes increasingly inflated due to the decreasing air pressure, eventually bursting as the gas inside expands to many times its volume at ground level.
The probe now begins to fall back to Earth. To prevent it from simply crashing into the ground, it is often equipped with a small parachute. However, it has been found that the small parachute is usually of little use and often gets tangled in the cords and doesn't deploy. It is said that it must be used anyway for insurance reasons.
A weather balloon is a balloon used in meteorology to transport measuring instruments, especially radiosondes.
Typical mission sequence[
A typical weather balloon is usually made of rubber and weighs only about 200 grams. The skin of a weather balloon is very delicate and fine, so it should only be handled with protective gloves. Even minimal damage that may have no consequences on the ground can lead to premature balloon bursting at high altitudes when the skin becomes increasingly tense.
The balloon is usually filled with helium or hydrogen. Unlike the rare and expensive helium, the latter is cheap and readily available, and its flammability is considered a manageable risk at the required quantities. The probe is attached to the weather balloon at a sufficient distance to avoid ascending in its slipstream. Since the balloon expands to a diameter of over twelve meters due to the decreasing air pressure with increasing altitude, the slipstream would become so large that the measurement results would be distorted enormously.
The weather balloon can reach a height of 20–30 km before it bursts and the probe returns to the ground with a parachute.
Story[
One of the first to use weather balloons was the French meteorologist Léon-Philippe Teisserenc de Bort. Starting in 1896, he conducted over 200 balloon experiments, often at night to eliminate measurement errors caused by radiant heat. The knowledge of the troposphere and stratosphere as layers of the Earth's atmosphere dates back to this time.