SLANT METEOROLOGICAL VISIBILITY

The slant meteorological visibilities VNS and V5S are the projections of the slant sight paths have regular transmittances of 2 and 5 per cent respectively on horizontal ground. As with the horizontal meteorological visibility for horizontal observations for slant observation, the slant meteorological visibility describes the maximum distance from an observation point at which diffused reflecting objects are detectable. The mathematical formula includes only the horizontal meteorological visibility on the ground and the relative run of the haze stratification; it can be solved by microcomputers. In some examples the runs of the visual ranges air-to-ground and ground-to-air are shown for typical meteorological situations. Thus, in practice, the slant meteorological visibility is likely to be a useful complement to the synoptically already disposable horizontal meteorological visibility. © 1979 Taylor and Francis Ltd.