A model study of global variability in mesospheric cloudiness

摘要: Abstract We have performed microphysical calculations of mesospheric cloudiness which are driven by output (vertical wind, water vapor mixing ratio and temperature) from a two-dimensional (2D) global chemical/dynamical model. The variations in the 2D model drive simulated clouds can be compared with cloud observations. specific observables we ice content, altitude, peak backscatter at 532 nm albedo 252 nm. categorize these parameters terms their latitude, solar activity hemisphere (north vs. south). In agreement observations, find brighter Northern Hemisphere (NH) relative to south minimum maximum. Also that altitudes higher Southern (SH) NH. Quantitatively, it appears may overstate magnitude variations. Thus, entire range observed altitudes, poleward 65–70°, is about 2 km (83–85 km), whereas calculated heights extends up 5 km (83–88 km). addition, cycle brightness change an order larger than limited available Since H 2 O variation 80–90 km region respect relatively small (10–40%), not cause our large variability. Rather, for both hemispheric changes, suggest temperature variability too great.