Convert the temperature of the selected area into Kelvin units. If your current temperature is in Celsius, add 273.15. For example, 15 C + 273.15 would be 288.15 K. If your temperature is in Fahrenheit, convert it to Kelvin by subtracting 32 and dividing the new number by 1.8. So, 60 F would be 15.56 K.
K= C + 273.15
C= (F - 32) / 1.8
Find the standard temperature lapse rate. The standard temperature lapse rate is measured at -2 Celsius per every 1000 meters. Divide the height above sea level by 1,000 and multiply by -2.
(Height above sea level / 1,000 m) x -2
Add the temperature to the standard temperature lapse rate. Call this number X.
Temperature + standard temperature lapse rate = X
Subtract the height of the troposphere, which is 11,000 m, from the height above sea level. Call this number Q.
Height above sea level - 11,000 = Q
Multiply X by Q. Create a fraction with the resulting number as the denominator. The temperature in Kelvins that you got from Step 1 is the numerator of the fraction.
Temperature in Kelvins/ (X x Q)
Raise the fraction you just created to an exponential power by placing an exponent next to the fraction. The power is also a fraction and contains two equations. Solve each exponent equation before you write it next to the fraction you created. For the denominator of the exponent fraction solve this equation: 8.31432 times the standard temperature lapse rate. The first number is the Universal Gas Constant (8.31432). The second number is the answer you got from Step 2.
The numerator of the fraction is found by solving the next equation: 9.80665 times .0289644. The first number (9.80665) is the gravitational acceleration of Earth. The second number is the molar mass of Earth's air.
Raise your original fraction to the power of the exponent fraction determined in Step 6. Your equation should look like this:
Temperature in Kelvins / X times Q raised to the power of 9.80665 times .28404373 / 8.31432 times the standard temperature lapse rate. Solve this equation and call it Z.
Calculate the final equation to find the barometric pressure. It is Z times the static pressure. The static pressure is 22632.1.
The barometric pressure is Z times 22632.1.