Wave Structure 960502 leg 4

Wave Structure (96502)

In the following gif images, several fields are plotted versus distance along DC-8 flight tracks upwind of the wave-cloud. Plots are shown for each of the 4 legs aligned with the wind. The fields plotted are:

-Potential temperature contours (vs. z and x) from MTP data (white) [B. Gary]
-MMS DC-8 static air temperature (red) [R. Chan]
-Laser hygrometer H2O mixing ratios (cyan) [G. Sachse]
-relative humidity with respect to ice (RHI) (green)
-CVI ice crystal number density (magenta) [Twohy, Gandrud]
The potential temperature surfaces slope upward/downward as the DC-8 flew into/out of the wave-cloud. The increase in RHI in the wave-crest is due to both the increase in H2O and the decrease in T. Updraft speeds estimated from the slope in theta surfaces and the wind speed range from 0.75 to 1.5 m/s. The peak CVI ice crystal number densities in wave-cloud penetrations (not shown) were 5-10/cc. Given the updraft speeds and temperatures, these number densities are consistent with theoretical calculations. Large peak supersaturations also occur at the leading edge of the cloud (20-50%).

All of the data shown here is preliminary. Refinements in calibrations are needed to improve accuracy.