CONDENSED WATER IN TROPICAL CYCLONE-OLIVER, 8-FEBRUARY-1993

On February 8, 1993, the NASA DC-8 aircraft profiled from 10,000 to 37 ,000 feet (3.1-11.3 km) pressure altitude in a stratified section of t ropical cyclone ''Oliver'' over the Coral Sea northeast of Australia. Size, shape and phase of cloud and precipitation particles were measur ed with a 2-D Greyscale probe. Cloud/precipitation particles changed f rom liquid to ice as soon as the freezing level was reached near 17,00 0 feet (5.2 km) pressure altitude. The cloud was completely glaciated at -5 degrees C. There was no correlation between ice particle habit a nd ambient temperature, In the liquid phase, the precipitation-cloud d rop concentration was 4.0 X 10(3) m(-3), the geometric mean diameter D -g = 0.5-0.7 mm, and the liquid water content 0.7-1.9 g m(-3), The lar gest particles anywhere in the cloud, dominated by fused dendrites at concentrations similar to that of raindrops (2.5 X 10(3) m(-3)) but a higher condensed water content (5.4 g m(-3) estimated) were found in t he mixed phase; condensed water is removed very effectively from the m ixed layer due to high settling Velocities of the large mixed particle s. The highest number concentration (4.9 X 10(4) m(-3)), smallest size (D-g = 0.3-0.4 mm), largest surface area (up to 2.6 X 10(2) cm(2) m(- 3) at 0.4-1.0 g m(-3) of condensate) existed in the ice phase at the c oldest temperature (-40 degrees C) at 35,000 feet (10.7 km), Each clou d contained aerosol (haze particles) in addition to cloud particles. T he aerosol total surface area exceeded that of the cirrus particles at the coldest temperature. Thus, aerosols must play a significant role in the upscattering of solar radiation. Light extinction (6.2 km(-1)) and backscatter (0.8 sr(-1) km(-1)) was highest in the coldest portion of the cirrus cloud at the highest altitude.