First ISCCP Regional Experiment (FIRE) Cirrus Phase I University of North Dakota Citation Aircraft 24 Hertz Data

The First ISCCP Regional Experiments have been designed to improve data products and cloud/radiation parameterizations used in general circulation models (GCMs). Specifically, the goals of FIRE are (1) to improve basic understanding of the interaction of physical processes in determining life cycles of cirrus and marine stratocumulus systems and the radiative properties of these clouds during their life cycles and (2) to investigate the interrelationships between the ISCCP data, GCM parameterizations, and higher space and time resolution cloud data.To-date, four intensive field-observation periods were planned and executed: a cirrus IFO (October 13-November 2, 1986); a marine stratocumulus IFO off the southwestern coast of California (June 29-July 20, 1987); a second cirrus IFO in southeastern Kansas (November 13-December 7, 1991); and a second marine stratocumulus IFO in the eastern North Atlantic Ocean (June 1-June 28, 1992). Each mission combined coordinated satellite, airborne, and surface observations with modeling studies to investigate the cloud properties and physical processes of the cloud systems.The University of North Dakota owns and operates a Cessna Citation II aircraft (N77ND) for the purpose of atmospheric research. This aircraft type has a number of design and performance characteristics which make it an ideal platform for a wide range of atmospheric studies. A series of structural modifications have been made to the basic airplane. These include the following: pylons under the wing tips for a variety of probes in the undisturbed air flow away from the fuselage; a nose boom for wind measurement; a heated radome to prevent ice accumulation on the nose area; special mounts for upward and downward looking radiometers; side-facing camera mounts for time-lapse cameras; optically-flat glass windows for photography; and an air inlet port for air sampling inside the pressurized cabin. The research instrumentation available on the Citation for the second Cirrus IFO is described below.For more information about the UND Citation see http://cumulus.atmos.und.edu/The data contained in the following file is 24 hertz data from the UND Citation II Weather Research Aircraft. Each record has 24 values of sixteen variables.The data order is:Number Variable Units24 values Date yymmdd24 values Time seconds from midnight24 values Pitotpressure, Nose millibars24 values Pitotpressure, Wing millibars24 values Vertical acceleration meters/second/second24 values Vertical wind meters/second24 values Static pressure millibars24 values Air temperature, Rosemount Celcius24 values True heading degrees24 values Wind direction degrees24 values Wind velocity meters/second24 values Angle of attack degrees24 values Angle of sideslip degrees24 values Replicator film speed24 values Replicator frame count24 values Replicator event mark