TABLES OF ATMOSPHERIC CONSTANTS/DATA

Analytical expressions for temperature, density, and other parameters with altitude were discussed in Section A1. The variations in pressure and temperature with altitude in a standard atmosphere are also available in the form of Tables (see Refs. [1,3]).

The standard atmosphere is thought to be based on the average pressure, temperature, and air density at various altitudes [12]. This information is very useful for engineering calculations for aircraft. It shows what pressures and temperatures are to be expected at various altitudes. The standard atmosphere is based on mathematical formulas that relate the temperature and pressure as altitude is gained or reduced. The results are close to averages of balloon and airplane measurements at these altitudes. Table A2 uses metric units.

A table using U. S. units—altitude in feet, temperature in Fahrenheit, and pressure in inches of mercury is given in Williams (www. usatoday. com/weather/wstdatmo. htm [USATODAY. com]). It gives density in slugs per cubic foot because it uses the American system. People often use pounds per cubic foot as a measure of density in the United States; however, pounds are a measure of force, not mass. Slugs are the correct measure of mass, and one needs to multiply slugs by 32.2 for a rough value in pounds.

TABLE A2

Standard Atmosphere Data