An aircraft is descending to land under IFR. If the local QNH is 1009 hPa, what will happen to the altitude reading when the altimeter is reset at the transition level?

1) During a flight over the sea at FL 100 from Marseille (QNH 1012 hPa) to Palma de Mallorca (QNH 1012 hPa), the true altitude is constantly increasing. What action, if any, should be taken?

2) After landing at an aerodrome (aerodrome elevation 1715 ft), the altimeter indicates an altitude of 1310 ft. The altimeter is set to the pressure value of 1013 hPa. What is the QNH at this aerodrome?

3) An aircraft is descending to land under IFR. If the local QNH is 1009 hPa, what will happen to the altitude reading when the altimeter is reset at the transition level?

4) Which feature is associated with the tropopause?

5) CO2 and H2O keep the atmosphere