Project #2004-109 AIRS-II Alliance Icing Research Study - II J. Hallett, et al. NSF/NCAR C-130Q Hercules (N130AR)

The Alliance Icing Research Study II (AIRS-II) has operational objectives to:

• develop techniques/systems to remotely detect, diagnose and forecast hazardous winter conditions at airports.
• improve weather forecasts of aircraft icing conditions.
• better characterize the aircraft-icing environment.
• improve our understanding of the icing process and its affect on aircraft.

In order to support the operational objectives, the following science objectives will be addressed to:

• investigate the conditions associated with supercooled large drop formation.
• determine conditions governing cloud glaciation.
• document the spatial distribution of ice crystals and supercooled water and the conditions under which they co-exist.
• verify the response of remote sensors to various cloud particles, and determine how this can be exploited to remotely determine cloud composition.

The NCAR/NSF C-130 research aircraft will operate out of Cleveland Ohio, to examine upwind aerosol conditions as well as cloud conditions over Mirabel Airport near Montreal. The NASA Twin Otter will operate along with the Canadian Convair from Ottawa. These aircraft will fly special flight operations over a network of ground in-situ and remote-sensing meteorological measurement systems, located at Mirabel. Some prototype airport weather forecasting systems, which use satellite and surface-based remote sensors, PIREPS, and numerical forecast models, will be evaluated during the project. The aircraft will also provide data to verify the remote-sensing algorithms, numerical forecast models, and forecast systems, used to detect and predict icing conditions.

AIRS II is an exciting collaborative effort among many scientists and organizations. It will assist in providing the aviation community better tools to avoid aircraft icing, and to improve the efficiency of airport operations. It will also enable some unique basic science objectives to be addressed such as: how supercooled large drops form, how cloud ice forms, and how to better remotely detect cloud properties.