BGonline.org Forums

message for Bob Koca (OT)

Posted By: Chuck Bower
Date: Sunday, 30 January 2011, at 12:56 a.m.

Speed of sound in a gas is proportional to square root of temperature. Although the pressure as a function of altitude is monotonically decreasing (think of pressure at altitude h as the weight per unit area of the column of gas above h), the temperature is not. Of course Temperature depends upon seasons and latitude as well. When we flew experiments on balloons to the top of the atmosphere, I was thinking the coldest temperature occurred about 50-60 kft. Coincidentally, our balloon flights launches were in New Mexico! (Helium balloons, not hot air balloons that Albuquerque is famous for. From Fort Sumner -- 65 miles from the Texas border on the eastern edge of the state.)