in international standard temperature ISA what happen to temp and pressure?

In the International Standard Atmosphere (ISA), the temperature and pressure decrease with increasing altitude. The standard temperature at sea level is 15 degrees Celsius (59 degrees Fahrenheit) and the standard pressure is 1013.25 millibars (29.92 inches of mercury). As altitude increases, the temperature decreases at a rate of approximately 1.98 degrees Celsius per 1,000 feet (6.5 degrees Celsius per kilometer) and the pressure decreases at a rate of approximately 1 inch of mercury (33.86 millibars) per 1,000 feet (100 meters).

In the International Standard Atmosphere (ISA), temperature and pressure vary with altitude as follows:

Temperature:

- At sea level: 15°C (59°F)
- Lapse rate in the troposphere: -6.5°C per 1,000 m (or -1.98°C per 1,000 ft)
- Temperature inversion in the stratosphere: Temperature increases with altitude

Pressure:

- At sea level: 1013.25 hPa (29.92 inHg)
- Pressure gradient in the troposphere: -11.27 hPa per 1,000 m (or -0.334 inHg per 1,000 ft)

Specifics:

- Troposphere: The lowest layer of the atmosphere, extending from sea level to about 11 km (36,000 ft). Temperature decreases with increasing altitude at a rate known as the lapse rate.

- Stratosphere: The layer above the troposphere, from about 11 km to 50 km (36,000 ft to 164,000 ft). Temperature increases with increasing altitude, due to the absorption of ultraviolet radiation by ozone.

- Mesosphere: The layer above the stratosphere, from about 50 km to 85 km (164,000 ft to 278,000 ft). Temperature decreases with increasing altitude.

ISA is a standardized atmosphere model used for aeronautical calculations, atmospheric modeling, and weather forecasting. It serves as a reference for comparing the performance of aircraft and other atmospheric vehicles.