Modeling quasi-biennial variability in the semiannual double peak

摘要: The interannual variability of the stratopause semiannual double peak as seen in methane measurements made by Halogen Occultation Experiment (HALOE) is investigated using a two-dimensional isentropic model. It found that observed reproduced when quasi-biennial oscillation (QBO) tropical lower stratosphere introduced into model and there are two distinct means which QBO affects tracer values. First, modulates westerly phase (SAO) selective damping parameterized waves responsible for producing this SAO This results modulation strength duration circulation, with it being stronger easterly than westerly. However, easterly, effect downwelling tropics negated subsequent upwelling; overall to reduce or eliminate trough peak. For downwelling, although weaker, also more persistent, giving deeper trough. Second, influences propagation planetary winter hemisphere, thereby an extratropical mesosphere. alters circulation region, upwelling extratropics above 0.5 hPa (defined at 15 hPa) causes lobe form only combined result processes produce winds but single summer hemisphere easterly. modeled agrees well displayed HALOE observations.