Atmospheric thermodynamics

gas layer surrounding Earth

Pressure (symbol: p or P) is the force applied perpendicular to the surface of an object per unit area over which that force is distributed. Gauge pressure (also spelled gage pressure) is the pressure relative to the ambient pressure.

temperature at which a solid turns liquid

thumb|upright=1.5|A picture of Earth's troposphere with its different cloud types of low to [[high altitudes casting shadows. Sunlight is reflected off the ocean, after it was filtered into a reddish light by passing through much of the troposphere at sunset. The above lying stratosphere can be seen at the horizon as a band of its characteristic glow of blue scattered sunlight.]] thumb|right|upright=1.35|Atmospheric circulation: the three-cell model of the Atmospheric circulation|circulation of the planetary atmosphere of the Earth, of which the troposphere is the lowest layer.

thumb|right|Aerosol of microscopic water droplets suspended in the air above a cup of hot tea after the water vapor has sufficiently cooled and condensed. Water vapor is an invisible gas, but the clouds of condensed droplets refract and scatter the sunlight and are thus visible. thumb|Droplets of water vapor in a pan. thumb|right|280px|Demonstration of evaporative cooling. When the sensor is dipped in ethanol and then taken out to evaporate, the instrument shows progressively lower temperature as the ethanol evaporates. thumb|Rain evaporating after falling on hot pavement

gaseous phase of water; unlike other forms of water, water vapor is invisible

transition of a substance directly from the solid to the gas state

temperature at which air becomes saturated with water vapour

thermodynamic process with zero heat transfer

reference values for temperature and pressure

thumb|Water dripping from a slab of [[ice and then freezing, forming icicles]] Freezing is a phase transition in which a liquid turns into a solid when its temperature is lowered below its freezing point.

thumb|A hair tension dial hygrometer with a nonlinear scale.

released or absorbed energy during a constant-temperature process

deviation from the normal change of an atmospheric property with altitude

thermodynamic process in which the temperature remains constant

thermodynamic process in which pressure remains constant

The mesopause is the point of minimum temperature at the boundary between the mesosphere and the thermosphere atmospheric regions. Due to the lack of solar heating and very strong radiative cooling from carbon dioxide, the mesosphere is the coldest region on Earth with temperatures as low as -100 °C (-148 °F or 173 K). The altitude of the mesopause for many years was assumed to be at around 85 km (53 mi), but observations to higher altitudes and modeling studies in the last 10 years have shown that in fact there are two mesopauses - one at about 85 km and a stronger on

thumb|Modern radiosondes showing progress of miniaturisationthumb|A Global Positioning System|GPS sonde, approx 220 × 80 ×75 mm (8.7 × 3.1 × 3 in) (with grounding station in the background, used to perform a 'ground check' and also recondition the humidity sensor)

relation between vapour pressure and temperature

thumb|Example of a thermal column between the ground and a cumulus

The thermopause is the atmospheric boundary of Earth's energy system, located at the top of the thermosphere. The temperature of the thermopause could range from nearly absolute zero to .

atmospheric model

recording of temperature

lowering of body temperature due to the passing-flow of lower-temperature air

mass per unit volume of earths atmosphere

heat exchanged by a body or thermodynamic system

atmospheric phenomenon

In physical chemistry, supersaturation occurs with a solution when the concentration of a solute exceeds the concentration specified by the value of solubility at equilibrium. Most commonly the term is applied to a solution of a solid in a liquid, but it can also be applied to liquids and gases dissolved in a liquid. A supersaturated solution is in a metastable state; it may return to equilibrium by separation of the excess of solute from the solution, by dilution of the solution by adding solvent, or by increasing the solubility of the solute in the solvent.

temperature read by a thermometer covered in water-soaked cloth

measure of heating or cooling used in agriculture

indicator of atmospheric instability used in meteorology

thumb|upright=2|Plot of humidex depending on temperature and relative humidity The humidex (short for humidity index) is an index number used by Canadian meteorologists to describe how hot the weather feels to the average person, by combining the effect of heat and humidity. The term humidex was coined in 1965. The humidex is a nominally dimensionless quantity (though generally recognized by the public as equivalent to the degree Celsius) based on the dew point.

temperature that a fluid would attain if adiabatically brought to a standard reference pressure

temperature index that accounts for the effects of humidity

Vertical rate of change of temperature in atmosphere

vapour pressure

physical quantity that expresses hot and cold in the atmosphere

temperature of a mass of air after all the water vapor has been extracted without exchanging mass or heat with its surroundings

Study of heat-to-work transformations and their reverse

specific altitude in the atmosphere

angular frequency at which a vertically displaced parcel will oscillate within a statically stable environment

temperature of dry air parcels that have a total pressure and density equal to a moist parcel of air

condition where the Earth's atmosphere is generally considered to be unstable

the height in the atmosphere at which a rising parcel of air reaches surrounding air of the same temperature

thermodynamic diagram used in weather analysis

quantity in atmospheric thermodynamics

height at which an air parcel becomes saturated

measure in meteorology

Measure of thunderstorm probability.

altitude relative to the standard atmosphere conditions

thumb|right|300px|Sample emagram

apparent temperature used to estimate the effect of temperature, humidity, wind speed, etc.; weighted average of wet-bulb temperature (weight 7), globe thermometer temperature (weight 2), and dry-bulb temperature (weight 1)

thumb|right|Tephigram thumb|right|Annotated tephigram

used to describe the type of heat transfer for a surface that has moisture

meteorological measure of the amount of water in the atmosphere

layer in which active turbulence has homogenized some range of depths.

weather phenomenon in which an air mass forms over a body of water

accumulation of cold air in a topographic depression