Radiative Budget in the Lower Tropical Stratosphere from the Combination of Balloon-Borne Lidar and Radiometric Measurements
Résumé
The atmospheric layer near the tropical tropopause (14–18.5 km), referred to as the Tropical Tropopause Layer (TTL), is a key region of the Earth’s atmosphere and the gateway to the stratosphere. Along their ascent through the extremely cold TTL ( <200K), air parcels undergo ice formation and freeze-drying, which is ultimately responsible for the dryness of the stratosphere, of dramatic importance for stratospheric chemistry and the Earth’s radiative balance. TTL ice clouds (cirrus) also directly affect the Earth’s radiative budget. Combined lidar and radiometric measurements onboard stratospheric balloons make it possible to estimate their radiative forcing at a fine scale.