The correct spelling of "international standard atmosphere" is [ɪntəˈnæʃənəl ˈstændərd ˈætmosfɪr]. The word "international" is pronounced as "in-ter-na-shuh-nl", "standard" as "stan-derd", and "atmosphere" as "at-muh-sfeer". The term represents a unit of pressure used in the field of aeronautics and meteorology. It is defined as the pressure required to support a column of mercury of 760 millimeters in a laboratory at sea level at a temperature of 15 degrees Celsius. The abbreviation for the international standard atmosphere is "ISA".
The International Standard Atmosphere refers to a model that defines the basic characteristics of the Earth's atmosphere under standard conditions. It is a globally recognized reference for meteorologists, pilots, engineers, and scientists to study and compare atmospheric phenomena.
The International Standard Atmosphere assumes a specific range of conditions at sea level, including a temperature of 15 degrees Celsius (59 degrees Fahrenheit), atmospheric pressure of 1013.25 hectopascals, relative humidity of 0%, and a dry air composition. It provides a standardized framework for calculating and predicting air density, pressure, temperature, and other relevant atmospheric properties at different altitudes.
The atmosphere is considered to be divided into multiple layers based on the International Standard Atmosphere's model. These layers include the troposphere, stratosphere, and mesosphere, each with distinct characteristics and variations in temperature and pressure distribution. This reference is essential for various scientific and practical applications, including aircraft design and operation, weather forecasting, and the study of atmospheric phenomena such as aerodynamics and climate change.
The International Standard Atmosphere provides a uniform framework for international cooperation, ensuring consistency in measurements and calculations related to atmospheric sciences. While real-world atmospheric conditions may deviate significantly from this standard, it serves as a valuable benchmark for comparison and analysis. Scientists and researchers utilize this model as a baseline to assess variations in atmospheric conditions across locations and time periods.