Measurements in Low Latitude High Altitude Cirrus

Measurements of particle size distributions from submicron sizes and above, in some instances ice water content, and relative humidity have been collected in midlatitudes during the MidCIX experiment in 2004 and in low latitudes during CRYSTAL-FACE in 2002, Pre-AVE in 2004, ACTIVE (Darwin) in 2005, and TWP-ICE (Darwin) in 2006. The observational temperatures begin at -45C and extent to -85C. We will report on the predominant ice habits, population-mean ice particle density, instances of aircraft icing, the evolution of ice particle populations in the vertical and horizontal and the role of aggregation in this process