gradient adiabatique saturé

CONT: Le refroidissement par détente [d'une particule d'air saturé en mouvement ascendant] provoque la condensation de la vapeur d'eau et la libération de la chaleur de condensation [...] Dans ce cas, la transformation n'est plus entièrement adiabatique, et la décroissance thermique se réduit à 0,5 °C par 100 m («gradient pseudo-adiabatique»).
OBS: En raison de la libération de chaleur latente, sa valeur est inférieure à celle du gradient adiabatique de l'air sec.

CONT: So, if condensation is taking place, latent heat is being released to the surrounding air. So you have two opposing trends going on at the same time within this parcel of air. It's rising and cooling, but it's also condensing and being warmed. Which one will win out? That is, will the air get colder, or will it get warmer? Well, what happens is that the air will still cool off, but not as fast. If water vapor in the air is condensing, the adiabatic rate is less. The air is only cooling off at a rate of about 5 degrees C/1000 meters (3.3 deg per 1000 feet). This is called the Saturated adiabatic lapse rate (or the wet adiabatic lapse rate, or the moist adiabatic lapse rate, depending on the textbook you are using). The saturated lapse rate varies with the original temperature of the air parcel, but 5 degrees C/1000 meters is a commonly used value.
OBS: The pseudoadiabatic lapse rate is so close to the moist adiabatic lapse rate that meteorologists tend to ignore this difference and often refer to them synonymously. In fact, on adiabatic charts (or pseudoadiabatic charts), the moist adiabatic lapse rate lines are referred to interchangeably as moist, saturated, or pseudoadiabatic.

OBS: Debido al desprendimiento del calor latente, su magnitud es inferior a la del gradiente adiabático del aire seco.