Atmospheric sounding
Encyclopedia
An atmospheric sounding is a measurement of vertical distribution of physical properties of the atmospheric
column such as pressure
, temperature
, wind speed
and wind direction
(thus deriving wind shear
), liquid water content, ozone
concentration, pollution, and other properties. Such measurements are performed in a variety of ways including remote sensing
and in situ observations.
The most common in situ sounding is a radiosonde
, which usually is a weather balloon
, but can also be a rocketsonde
.
Remote sensing soundings generally use passive infrared
and microwave
radiometer
s:
There is even a sounder at Mars: the Mars climate sounder
on the Mars Reconnaissance Orbiter
.
Atmosphere
An atmosphere is a layer of gases that may surround a material body of sufficient mass, and that is held in place by the gravity of the body. An atmosphere may be retained for a longer duration, if the gravity is high and the atmosphere's temperature is low...
column such as pressure
Atmospheric pressure
Atmospheric pressure is the force per unit area exerted into a surface by the weight of air above that surface in the atmosphere of Earth . In most circumstances atmospheric pressure is closely approximated by the hydrostatic pressure caused by the weight of air above the measurement point...
, temperature
Temperature
Temperature is a physical property of matter that quantitatively expresses the common notions of hot and cold. Objects of low temperature are cold, while various degrees of higher temperatures are referred to as warm or hot...
, wind speed
Wind speed
Wind speed, or wind velocity, is a fundamental atmospheric rate.Wind speed affects weather forecasting, aircraft and maritime operations, construction projects, growth and metabolism rate of many plant species, and countless other implications....
and wind direction
Wind direction
Wind direction is reported by the direction from which it originates. For example, a northerly wind blows from the north to the south. Wind direction is usually reported in cardinal directions or in azimuth degrees...
(thus deriving wind shear
Wind shear
Wind shear, sometimes referred to as windshear or wind gradient, is a difference in wind speed and direction over a relatively short distance in the atmosphere...
), liquid water content, ozone
Ozone
Ozone , or trioxygen, is a triatomic molecule, consisting of three oxygen atoms. It is an allotrope of oxygen that is much less stable than the diatomic allotrope...
concentration, pollution, and other properties. Such measurements are performed in a variety of ways including remote sensing
Remote sensing
Remote sensing is the acquisition of information about an object or phenomenon, without making physical contact with the object. In modern usage, the term generally refers to the use of aerial sensor technologies to detect and classify objects on Earth by means of propagated signals Remote sensing...
and in situ observations.
The most common in situ sounding is a radiosonde
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...
, which usually is a weather balloon
Weather balloon
A weather or sounding balloon is a balloon which carries instruments aloft to send back information on atmospheric pressure, temperature, humidity and wind speed by means of a small, expendable measuring device called a radiosonde...
, but can also be a rocketsonde
Rocketsonde
A rocketsonde, a kind of sounding rocket, is a system for atmospheric observations that consists of a rocket that launches instruments that can make weather observations up to an altitude of 75,000 m. Common meteorological rockets are the Loki and Super Loki.A typical rocket is 3.7 m tall and is...
.
Remote sensing soundings generally use passive infrared
Infrared
Infrared light is electromagnetic radiation with a wavelength longer than that of visible light, measured from the nominal edge of visible red light at 0.74 micrometres , and extending conventionally to 300 µm...
and microwave
Microwave
Microwaves, a subset of radio waves, have wavelengths ranging from as long as one meter to as short as one millimeter, or equivalently, with frequencies between 300 MHz and 300 GHz. This broad definition includes both UHF and EHF , and various sources use different boundaries...
radiometer
Radiometer
A radiometer is a device for measuring the radiant flux of electromagnetic radiation. Generally, the term radiometer denotes an infrared radiation detector, yet it also includes detectors operating on any electromagnetic wavelength....
s:
- airborne instruments
- surface stations
- Earth-observing satellite instruments such as AIRSAtmospheric Infrared SounderThe Atmospheric Infrared Sounder is one of six instruments flying on board NASA’s Aqua satellite, launched on May 4, 2002. The instrument is designed to support climate research and improve weather forecasting....
and AMSUAdvanced Microwave Sounding UnitThe Advanced microwave sounding unit is a multi-channel microwave radiometer installed on meteorological satellites. The instrument examines several bands of microwave radiation from the atmosphere to perform atmospheric sounding of temperature and moisture levels.-Products:Level-1 radiance data...
There is even a sounder at Mars: the Mars climate sounder
Mars climate sounder
The Mars climate sounder is a major instrument on the Mars Reconnaissance Orbiter. The Mars Climate Sounder will look both down and horizontally through the atmosphere in order to quantify the global atmosphere’s vertical variations of water vapor, dust and temperature...
on the Mars Reconnaissance Orbiter
Mars Reconnaissance Orbiter
Mars Reconnaissance Orbiter is a NASA multipurpose spacecraft designed to conduct reconnaissance and Exploration of Mars from orbit...
.