Unit used to measure the abundance of ozone in the atmosphere. One Dobson unit is the equivalent of 2.69/ x 1016 molecules of ozone/cm2.
A unit used to measure the thickness of the ozone layer. It can be visualized as a tube extending up into the stratosphere, capturing ozone (and other gases) as it goes. If all of the ozone in that tube was compressed into the bottom at a standard temperature and pressure, it would form a stack millimeters high. This number () multiplied by 100 is the number of Dobson Units.
a measurement of how thick a specific portion of the ozone layer would be if it were compressed into a single layer at zero degrees Celsius with one unit of atmospheric pressure acting on it (standard temperature and pressure - STP)
a unit of measurement that describes the thickness of the ozone layer in a column above the location being measured
The standard unit of measure for ozone. If all of the ozone from the Earth's surface to outer space were compressed to standard temperature and pressure (STP), the ozone layer or its thickness would be about 3 mm thick. At STP, 3mm of ozone is 300 Dobson Units (DU). 1mm = 100DU.
Unit of measurement of totatal ozone column abundance, named for G.M.B. Dobson, a pioneer in measurement of ozone. One Dobson unit corresponds to 2.6*1O16 molecules cm-2 of total overhead colomn ozone.
a measure of the total amount of ozone in a column of the atmosphere (total column ozone) from ground level to the top of the atmosphere, based on analysis of absorbed ultraviolet light. The number of Dobson units corresponds directly with the “thickness” of the ozone layer. While measurements vary widely according to time and place, a typical reading for a healthy polar ozone layer might be in the 300-450 Dobson unit range.
a measurement of column ozone levels. If 100 DU of ozone were brought to the Earth's surface, it would form a layer 1 millimeter thick. In the tropics, ozone levels are typically between 250 and 300 DU year-round. In temperate regions, seasonal variations can produce large swings in ozone levels. For instance, measurements in Leningrad have recorded ozone levels as high as 475 DU and as low as 300 DU. These variations occur even in the absence of ozone depletion, but they are well understood. Ozone depletion refers to reductions in ozone below normal levels after accounting for seasonal cycles and other natural effects. For a graphical explanation, see NASA's TOMS site.
the unit used to measure the column of ozone above a given location. If all the ozone in the atmosphere was compressed at the pressure found at the ground it would be 1 to 6 millimeters (mm) thick. One hundred Dobson Units (100 DU) - 1 mm thickness of ozone at sea level.
A measure of total ozone in a vertical column. One Dobson unit is equal to a depth of 0.001 mm at standard temperature and pressure.
The unit of `Column (or Total) Ozone' - the amount of ozone directly above a point on the Earth's surface. More Information.
The standard way to express ozone amounts in the atmosphere. One DU is 2.7 x 10 exp 16 (10 to the 16th power) ozone molecules per square centimeter. One Dobson unit refers to a layer of ozone that would be 0.001 cm thick under conditions of standard temperature (0 degree C) and pressure (the average pressure at the surface of the Earth). For example, 300 Dobson units of ozone brought down to the surface of the Earth at 0 degree C would occupy a layer only 0.3 cm thick in a column. Dobson was a researcher at Oxford University who, in the 1920s, built the first instrument (now called the Dobson meter) to measure total ozone from the ground.
Unit of measurement used to measure thickness of ozone layer at STP.
A unit measuring the total amount of ozone in a vertical column above the Earth's surface in the stratosphere. A value of less than 200DU is associated with the presence of an ozone hole.
A unit used in the measure of the column abundance of ozone in the atmosphere. One Dobson unit is the equivalent of 2.69 × 1016 molecules of ozone per square centimeter. Alternatively, 1 Dobson unit corresponds to a layer of ozone 10 μm thick, if the ozone were held at standard temperature and pressure (273 K, 1 atm pressure).
Units of ozone level measurement. measurement of ozone levels. If, for example, 100 DU of ozone were brought to the earth's surface they would form a layer one millimeter thick. Ozone levels vary geographically, even in the absence of ozone depletion.
Dobson units (DU) are the standard way to express ozone amounts in the atmosphere, specifically the statosphere. One DU is 2.69 × 1016 ozone molecules per square centimetre, or 2.69 × 1020 per square meter. One Dobson unit refers to a layer of ozone that would be 10 micrometres thick under standard temperature and pressure.