O3, NO y , and NO x /NO y in the upper troposphere of the equatorial Pacific

摘要: Two of the DC-8 flights during 1991-1992 second Airborne Arctic Stratospheric Expedition (AASE 2) were between California and Tahiti. Extremely abrupt changes in O 3 NO y observed on both as aircraft crossed subtropical jet. They indicate that width transition from midlatitude to tropical air troposphere can be short 1 km. The /O ratio was remarkably stable across transition. We discuss some dynamical features associated with transitions speculate reasons for their abruptness. occurred south frontal zone accompanied by humidity, x /NO , modest CO, CH 4 CO 2 . In addition, a chemical model constrained measurements long-lived species is used simulate variation along two flight tracks. Although this quite successful at simulating air, it drastically overestimates air. rate which converts HNO via + OH reaction very slow upper because low concentrations cold temperatures force most form day. argue there an important pathway region not presently included models, much (possibly aerosol) readily converted or has been insufficient time since convection released other more forms It resolve discrepancy present models have correct may overestimate production rates troposphere.