Atmospheric dynamics (category)
Weather (category) · (portal)
Atmospheric thermodynamics is the study of heat to work transformations (and the reverse) in the earth’s atmospheric system in relation to weather or climate. Following the fundamental laws of classical thermodynamics, atmospheric thermodynamics studies such phenomena as properties of moist air, formation of clouds, atmospheric convection, boundary layer meteorology, and vertical stabilities in the atmosphere. Atmospheric thermodynamic diagrams are used as tools in the forecasting of storm development. Atmospheric thermodynamics forms a basis for cloud microphysics and convection parameterizations in numerical weather models, and is used in many climate considerations, including convective-equilibrium climate models.
Atmospheric thermodynamics focuses on water and its transformations. Areas of study include the law of energy conservation, the ideal gas law, specific heat capacities, adiabatic processes (in which entropy is conserved), and moist adiabatic processes. Most of tropospheric gases are treated as ideal gases and water vapor is considered as one of the most important trace components of air.
The atmosphere of Earth is a layer of gases surrounding the planet Earth that is retained by Earth's gravity. The atmosphere protects life on Earth by absorbing ultraviolet solar radiation, warming the surface through heat retention (greenhouse effect), and reducing temperature extremes between day and night (the diurnal temperature variation).
The common name given to the atmospheric gases used in breathing and photosynthesis is air. By volume, dry air contains 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.039% carbon dioxide, and small amounts of other gases. Air also contains a variable amount of water vapor, on average around 1%. While air content and atmospheric pressure vary at different layers, air suitable for the survival of terrestrial plants and terrestrial animals currently is only known to be found in Earth's troposphere and artificial atmospheres.
A capping inversion is an elevated inversion layer that caps a convective boundary layer.
The boundary layer is the part of the atmosphere which is closest to the ground. Normally, the sun heats the ground, which in turn heats the air just above it. Thermals form when this warm air rises into the cold air (warm air is less dense than cold air), a process known as convection. A convective layer such as this has the potential for cloud formation, since condensation occurs as the warm air rises and cools.
A marine layer is an air mass which develops over the surface of a large body of water such as the ocean or large lake in the presence of a temperature inversion. The inversion itself is usually initiated by the cooling effect of the water on the surface layer of an otherwise warm air mass. As it cools, the surface air becomes denser than the warmer air above it, and thus becomes trapped below it. The layer may thicken through turbulence generated within the developing marine layer itself. It may also thicken if the warmer air above it is lifted by an approaching area of low pressure. The layer will also gradually increase its humidity by evaporation of the ocean or lake surface, as well as by the effect of cooling itself. Fog will form within a marine layer where the humidity is high enough and cooling sufficient to produce condensation. Stratus and stratocumulus will also form at the top of a marine layer in the presence of the same conditions there.
In the case of coastal California, the offshore marine layer is typically propelled inland by a pressure gradient which develops as a result of intense heating inland, blanketing coastal communities in cooler air which, if saturated, also contains fog. The fog lingers until the heat of the sun becomes strong enough to evaporate it, often lasting into the afternoon during the "May gray" or "June gloom" period. An approaching frontal system or trough can also drive the marine layer onshore. With Southern California's high concentration of military bases, a marine layer propelled inland can be colloquially described as "the marines coming inland".
A disaster is a natural or man-made (or technological) hazard resulting in an event of substantial extent causing significant physical damage or destruction, loss of life, or drastic change to the environment. A disaster can be ostensively defined as any tragic event stemming from events such as earthquakes, floods, catastrophic accidents, fires, or explosions. It is a phenomenon that can cause damage to life and property and destroy the economic, social and cultural life of people.
In contemporary academia, disasters are seen as the consequence of inappropriately managed risk. These risks are the product of a combination of both hazard/s and vulnerability. Hazards that strike in areas with low vulnerability will never become disasters, as is the case in uninhabited regions.