Standardatmosfärens

Standardatmosfärens refers to a model atmosphere that defines a set of physical properties, such as temperature, pressure, and density, at different altitudes. This model serves as a reference for various applications, particularly in aviation and aerospace. It is not a description of the actual Earth's atmosphere at any given moment, but rather a simplified, idealized representation.

The most commonly used standard atmosphere is the International Standard Atmosphere (ISA). The ISA model specifies a sea-level temperature of 15 degrees Celsius (288.15 Kelvin) and a sea-level pressure of 1013.25 hectopascals (hPa) or 1 atmosphere. The temperature is assumed to decrease linearly with altitude up to a certain height, after which it remains constant for a period before increasing again. These defined values and profiles are crucial for calibrating aircraft instruments, calculating aerodynamic performance, and conducting meteorological research.

The concept of a standard atmosphere is essential for ensuring consistency and comparability across different studies and operations. For instance, when aircraft are certified or their performance is evaluated, it is done under standardized atmospheric conditions. This allows for a common baseline against which to measure and compare. Variations from the standard atmosphere are accounted for in real-time operational adjustments.