Validation of the 1/12 degrees Arctic Cap Nowcast/Forecast System (ACNFS)

Abstract : Naval Research Laboratory has compared sea ice hindcast for the Arctic Ocean derived from the latest coupled ice-ocean prediction system to observations. The system is based on the HYbrid Coordinate Ocean Model coupled via the Earth System Modeling Framework to the Los Alamos Community Ice CodE and tested using the Navy Coupled Ocean Data Assimilation system. The validation of the 1/12 degree Arctic Cap Nowcast/ Forecast System (ACNFS) was accomplished by comparing hindcast fields to the current operational Polar Ice Prediction System (PIPS 2.0) as well as comparing to observations. Both the ACNFS and PIPS 2.0 output daily fields of ice thickness, ice concentration, and ice drift. The goal of the validation is to determine if the new ACNFS is an improvement over the existing PIPS 2.0 model and should be used, operationally, in its place. NRL validated hindcasts and forecasts of ice edge location, ice thickness, ice draft, and ice drift using observational data sets such as daily ice edge, ice mass balance buoys, ice thickness survey flight data, upward looking sonars data and Special Sensor Microwave/Imager ice concentration data. NRL evaluated the models against these data during the years 2007-2009 depending on the availability of the observations.

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