Balloon-borne observations of water vapor and ozone in the tropical upper troposphere and lower stratosphere

摘要: [1] Balloon-borne observations of frost-point temperature and ozone in the equatorial western, central eastern Pacific as well over Brazil provide a highly accurate data set water vapor across tropical tropopause. Data were obtained at San Cristobal, Galapagos, Ecuador (0.9°S, 89.6°W), during late northern winter summer 1998 1999 Juazeiro do Norte, (7.2°S, 39.3°W), February November 1997. Earlier western region March 1993 reanalyzed to extend scope observations. The show three different circumstances which saturation or supersaturation occurs imply mechanisms for dehydration tropopause: (1) convective dehydration, (2) slow-ascent (3) large-scale wave-driven dehydration. Furthermore, air that crosses tropopause may be dehydrated further fall, average rises cools. Not all soundings there are clear differences frequency depth regions seasons. transition can identified measurements relative humidity, even under conditions where ambiguous. Deep convection plays an important role setting up this region, is then subject wave activity breaking midlatitude intrusions. High humidities strong subsidence descending motion troposphere limited levels below region.