How does Total Air Temperature (TAT) differ from Static Air Temperature (SAT)?

Total Air Temperature (TAT) is indeed warmer than Static Air Temperature (SAT) primarily due to the effects of aerodynamic heating. As an aircraft moves through the air, the friction generated between the aircraft's surface and the air molecules creates a rise in temperature, which is attributed to this aerodynamic heating. TAT represents the total heat being experienced by the aircraft, which includes the kinetic energy of the air itself as well as the thermal energy due to the aircraft's movement through it.

In contrast, SAT is a measure of the air temperature that is not influenced by the aircraft's motion and is usually determined through static sensing devices, which provide a temperature reference unaffected by the aircraft's speed. Therefore, under normal flying conditions, TAT will reflect a higher temperature than SAT because of this additional heat component contributed by the aircraft's forward motion.

Other options do not accurately represent the relationship between TAT and SAT. For instance, while it is true that temperature can decrease with altitude, SAT is not necessarily cooler than TAT because of altitude alone as each temperature is defined by different variables. Similarly, TAT and SAT are not the same under standard conditions because the phenomena of aerodynamic heating affect TAT, and TAT is not exclusively measured at sea level,