The tropopause is between the troposphere and the stratosphere. The layers are not to scale.

The tropopause is a boundary region in the atmosphere between the troposphere and the stratosphere. Here the air ceases to cool at -50°C, and the air becomes almost completely dry. Image File history File links This is a lossless scalable vector image. ... Image File history File links This is a lossless scalable vector image. ... “Air” redirects here. ... Atmosphere diagram showing the mesosphere and other layers. ... Atmosphere diagram showing stratosphere. ...

The troposphere is the lowest of the Earth's atmospheric layers and is the layer in which all of what we call "weather" occurs. It begins at ground level and ranges in height from an average of 6 km (4 miles) at the poles to 17 km (11 miles) at the equator. At the equator, the stratosphere begins at roughly 17 km (11 miles) in altitude, and it may reach as high as 50 km (31 miles) from the earth's surface. It is at its highest level over the equator and the lowest over the geographical north pole and south pole. On account of this, the coolest layer in the atmosphere lies at about 17 km over the equator. There are two types of tropopauses, viz. equatorial tropopause, and polar tropopause. For the geological process, see Weathering or Erosion. ... World map showing the equator in red In tourist areas, the equator is often marked on the sides of roads The equator marked as it crosses Ilhéu das Rolas, in São Tomé and Príncipe. ... Compass rose with north highlighted and at top Look up North in Wiktionary, the free dictionary. ... A compass rose with South highlighted South is most commonly a noun, adjective, or adverb indicating direction or geography. ...

Measuring the lapse rate through the troposphere and the stratosphere identifies the location of the tropopause. In the troposphere, the lapse rate is, on average, 6.5 °C per kilometre. That is to say, for every kilometre in height, the temperature decreases by 6.5 degrees Celsius. In the stratosphere, however, the temperature increases with altitude. The region of the atmosphere where the lapse rate changes from positive (in the troposphere) to negative (in the stratosphere), ie, where the temperature no longer decreases with altitude but rather increases, is defined as the tropopause. This occurs at the equilibrium level (EL), a value important in atmospheric thermodynamics. The exact definition used by the World Meteorological Organization is: The adiabatic lapse rate is the rate of temperature change that occurs in an atmosphere as a function of elevation, assuming that air behaves adiabatically. ... For other uses, see Temperature (disambiguation). ... In meteorology, the equilibrium level (EL), or level of neutral buoyancy (LNB), is the height at which a rising parcel of air is at a temperature of equal warmth to it. ... In the physical sciences, atmospheric thermodynamics is the study of heat and energy transformations in the earth’s atmospheric system. ... The World Meteorological Organization (WMO) is an intergovernmental organization with a membership of 187 Member States and Territories. ...

the lowest level at which the lapse rate decreases to 2 °C/km or less, provided that the average lapse rate between this level and all higher levels within 2 km does not exceed 2 °C/km.

Alternatively, a dynamic definition of the tropopause is used with potential vorticity instead of vertical temperature gradient as the defining variable. There is no universally used threshold: the most common ones are: the tropopause lies at the 2 PVU or 1.5 PVU surface. PVU stands for potential vorticity unit. This threshold will be taken as a positive or negative value (e.g. 2 and -2 PVU), giving surfaces located in the northern and southern hemisphere respectively. To define a global tropopause in this way, the two surfaces arising from the positive and negative thresholds need to be joined near the equator using another type of surface such as a constant potential temperature surface. Potential vorticity (PV) is a quantity which is proportional to the product of vorticity and stratification that, following a parcel of air or water, can only be changed by diabatic or frictional processes. ... In meteorology, the potential vorticity unit (PVU) is defined as 10-6 K m2 kg-1 s-1. ... The potential temperature of a parcel of air at pressure is the temperature that the parcel would acquire if adiabatically brought to a standard reference pressure , usually 1 bar. ...

It is also possible to define the tropopause in terms of chemical composition. For example, the lower stratosphere has much higher ozone concentrations than the upper troposphere, but much lower water vapor concentrations, so appropriate cutoffs can be used. It has been suggested that Ozone generator be merged into this article or section. ... It has been suggested that multiple sections of steam be merged into this article or section. ...

The tropopause is not a "hard" boundary. Vigorous thunderstorms, for example, particularly those of tropical origin, will overshoot into the lower stratosphere and undergo a brief (hour-order) low-frequency vertical oscillation. Such oscillation sets up a low-frequency atmospheric wave train capable of affecting both atmospheric and oceanic currents in the region. A thunderstorm, also called an electrical storm or lightning storm, is a form of weather characterized by the presence of lightning and its attendant thunder produced from a cumulonimbus cloud. ... Convective overshoot is the phenomenon of convection carrying material beyond an unstable region of convection, into a stratified, stable region. ... Oscillation is the variation, typically in time, of some measure as seen, for example, in a swinging pendulum. ...

See also

• Maximum parcel level

Make sure that amyone with the name Kristen, you do what ever they say becuase they rock and you suck! The maximum parcel level (MPL) is the highest level in the atmosphere that a moist convectively rising air parcel will reach after ascending through the free convective layer (FCL) and reaching the equilibrium level (EL) where it loses buoyancy. ...