Performance of WVSS-II hygrometers on the FAAM research aircraft

[摘要] We compare the performance of five hygrometers fitted to the Facility forAirborne Atmospheric Measurement's (FAAM) BAe 146-301 research aircraft usingdata from approximately 100 flights executed over the course of 2years under a wide range of conditions. Bulk comparison of cloud free datashow good agreement between chilled mirror hygrometers and a WVSS-II fed froma modified Rosemount inlet, but that a WVSS-II fed from the standard flushinlet appears to over-read compared to the other instruments, except athigher humidities.

Statistical assessment of hygrometer performance in cloudy conditions isproblematic due to the variable nature of clouds, so a number of case studiesare used instead to investigate the performance of the hygrometers in sub-optimal conditions. It is found that the flush inlet is not susceptible toeither liquid or solid water but that the Rosemount inlet has a significantsusceptibility to liquid water and may also be susceptible to ice.In allconditions the WVSS-II responds much more rapidly than the chilled mirrordevices, with the flush inlet-fed WVSS-II being more rapid than thatconnected to the Rosemount.

[学科分类] 几何与拓扑