Data from a single penetration (cloud #22) into the wind. Aircraft true airspeed 100 m s-1.
Cloud width 8km. Aircraft in cloud 95 s. Parcel transit time estimated ~430 s,
parcel time = aircraft time * (TAS + Wind)/Wind
As in earlier figure of five wave cloud series, the 1D probe (200x) measured greater crystal concentration than 2D-C. Notice that 2D-C detects more snow crystals on the downwind side (left). This appearance of higher snow concentration
Downwind is an artifact of the size threshold for detection. Detection is size-dependent < 100um. 1D probe data indicate that the snow particles were already present on the upwind side.
Ice cloud is shifted downwind relative to water cloud. A few large particles were seen upwind of the water cloud, suggesting a deposition nucleation process. IN conc are in general agreement with crystal conc. Nucleation points of ice crystals can be inferred theoretically by modeling - growing them backwards from their observed sizes.
Ice nuclei concentration measured with CFD chamber at –20°C and 3% to 10% water supersaturation.