By Nathan A. Ferguson
The slippery business of assessing current and future icing conditions should be improving as scientists hone in on what is actually occurring in the atmosphere.
Pilots accustomed to using supplemental weather information, such as the Current and Forecast Icing Products (CIPs and FIPs) on the Aviation Digital Service (ADDS) Web site, have recently seen enhancements to the products. The products are graphically assigning different levels of severity instead of straight probabilities, which made it difficult for pilots to predict how much ice they might encounter.
Now scientists at the National Center for Atmospheric Research (NCAR) are verifying the variety of tools, from satellite/radar mosaics to pilot reports, used to determine cloud information.
It hasn’t been easy. No single instrument can detect and measure multiple cloud layers in three dimensions. In 2006, NASA launched a series of satellites, including CloudSat that maps the top and bottom of most cloud layers beneath it.
NCAR scientists found that CIP and FIP tend to over predict the thickness of low clouds by making the cloud tops too high. They are now working to correct this bias, which should provide more accurate data for pilots.
For more information on icing, see Thomas A. Horne’s “Weather Watch” department from AOPA Pilot.
February 7, 2008