The Polar Ice Prediction System - A Sea Ice Forecasting System

• Main Authors: Preller, Ruth H., Posey, Pamela G.
• Other Authors: NAVAL OCEAN RESEARCH AND DEVELOPMENT ACTIVITY STENNIS SPACE CENTER MS
• Format: Text
• Language: English
• Published: 1989
• Subjects: Snow; Ice and Permafrost; *ICE FORECASTING; *SEA ICE; POSITION(LOCATION); THERMODYNAMICS; EDGES; FORECASTING; ACCURACY; OPERATIONAL EFFECTIVENESS; TIME; DRIFT; ICE; SURFACE PROPERTIES; MATHEMATICAL PREDICTION; PRESSURE; CONCENTRATION(COMPOSITION); HEAT FLUX; OCEAN MODELS; GEOSTROPHIC WIND; ARCTIC REGIONS; EARTH ATMOSPHERE; BUOYS; POLAR REGIONS; TEST AND EVALUATION; MATHEMATICAL MODELS; PIPS(POLAR ICE PREDICTION SYSTEM); ICE DRIFT; FORCING FUNCTIONS; PE63207N; WUNORDN894428; Arctic; Ice; permafrost; Sea ice
• Online Access: http://www.dtic.mil/docs/citations/ADA214600; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA214600

The Polar Ice Prediction System PIPS, based on the Hibler dynamic/ thermodynamic sea ice model, was developed as an upgrade to the existing sea ice products available at the Navy's Fleet Numerical Oceanography Center (FNOC). It was also designed to provide new sea ice products that could be used as guidance by the Naval Polar Oceanography Center (NPOC). Operational testing of PIPS showed that the ice drift from the model was excessive in magnitude when compared to ice drift from Arctic buoys. As a result, the PIPS forcing was changed from planetary boundary layer model winds to geostrophic winds calculated from forecast surface pressures. Resultant PIPS ice drifts were more accurate than those calculated by the existing operational model-the Thorndike and Colony free-drift model. The operational test also indicated a need to reduce the model time step from 24 to 6 hours. Reducing the time step allowed for better resolution of atmospheric heat fluxes and improved the model's capability to predict ice edge location. PIPS results also showed great improvement when updated by an ice concentration analysis for the Arctic derived by NPOC. This updating technique is now an integral part of the PIPS system and takes place approximately once per week. As a result of this testing and the associated improvements made to the model, PIPS was declared operational 1 September 1987. Examples of PIPS output and results from model-data comparisons are presented. Prepared in collaboration with Berkeley Research Associates, Springfield, VA.