Daily Summary for 9 December 2007

A low near James Bay and a jet streak at 500mb brought plenty of cloud cover to Ontario. Warmer southwest flow killed the lake effect and eroded away the boundary layer stratocumulus from south to north during the day, but the mid- and upper levels had plenty of cloud.

The flight targeted the ~13:17 LT Kingston CloudSat overpass. We ran a successful CLEX mission today with CloudSat overpass. An ice cloud with bases at -25°C and a liquid water cloud (with a touch of ice - marginal mixed phase) at low levels (-5°C) was sampled with lidar and radar during Cloudsat overpass. After the the overpass, we sampled the ice cloud with in-situ probes using a spiral ascent to 24,000 ft. It had mostly irregular ice with ice water contents < 0.1 g/m3. Visually, on lidar and radar, we saw several narrow, horizontally patchy liquid water/mixed phase layers between 5 km and 3 km. Because of the fleeting nature, it was not possible to sample these in-situ. At one point, we had a total of 4 layers (one ice and 3 likely water/mixed phase) on radar.

This was truly a CLEX - cloud layer case. We then sampled a low level cloud with tops at -5°C. It was mostly liquid with high LWC (up to 0.3 g/m3) and the occassional ice particle. The ice habits were primarily columnar and were very low in concentration.

1815 UTC GOES-12 visible image and CloudSat swath during the flight