Modifications To Advanced Circulation Water Density Engine For Global Grids

THE NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION’S (NOAA) ACQUISITION & GRANTS OFFICE, EASTERN ACQUISITION DIVISION-NORFOLK, NATIONAL OCEAN SERVICE (NOS) NATIONAL GEODETIC SURVEY (NGS) OFFICE, INTENDS TO NEGOTIATE AND AWARD A PURCHASE ORDER, ON A SOLE SOURCE BASIS, UNDER AUTHORITY OF RFO FAR 6.103-1, WITH THE UNIVERSITY OF NOTRE DAME FOR MODIFICATIONS TO THE DEPTH-AVERAGED WATER DENSITY ENGINE, ADVANCED CIRCULATION (ADCIRC), IN ORDER TO PROVIDE GLOBAL GRIDS (WATER LEVEL DATUMS) AND OTHER MULTI-YEAR WATER LEVEL PRODUCTS THAT WILL IMPROVE NOAA TIDALLY-REFERENCE AIRBORNE OPERATIONS. NO SET ASIDE IS TO BE USED FOR THIS SOLE SOURCE REQUIREMENT. THE ASSOCIATED NAICS CODE IS 541715. THE SOLE SOURCE DETERMINATION IS BASED ON NOAA’S REQUIREMENT THAT THE UNIVERSITY OF NOTRE DAME IS THE ORIGINAL DEVELOPER OF THE ADCIRC OCEAN MODEL AND NO OTHER VENDORS HAVE AN OCEAN MODEL PROGRAM THAT MEETS NOAA'S TIDALLY-REFERENCED AERIAL IMAGERY OPERATIONAL

REQUIREMENTS. LONG-TERM HINDCAST MARINE GRIDS (AT DIFFERENT WATER LEVEL DATUMS) AND IMPROVEMENTS TO THE OCEAN MODEL WILL ALLOW INVESTIGATION OF APPROPRIATE TIME WINDOWS MONTHS AHEAD OF PLANNED FLIGHTS. IT WILL RELY ONLY ON ASTRONOMICAL TIDAL INFORMATION, WHICH IS AVAILABLE WITH MONTHS TO YEARS OF LEAD TIME. THESE

REQUIREMENTS ARE MEANT TO INCLUDE FACTORS, SUCH AS ATMOSPHERIC FORCING MEANS THAT THE OBSERVED WATER LEVELS MAY DIFFER FROM PREDICTIONS. THEREFORE, TIME WINDOWS MAY ALSO DIFFER FROM THOSE CALCULATED WITH MODEL WATER LEVELS. THE STEPS REQUIRED FOR THE DEVELOPMENT INCLUDE: IDENTIFICATION OF APPROPRIATE DATA SOURCES AND OR MODELS. INTERFACE WITH EXISTING PACKAGE ARCHITECTURE. TESTING THE DEPTH-AVERAGED WATER DENSITY ENGINE, CALLED ADVANCED CIRCULATION (ADCIRC), WAS IDENTIFIED AS AN OPERATION READY OPEN-SOURCE MODEL ENGINE THAT CAN GENERATE TIDALLY-REFERENCE MARINE GRIDS. THE ENGINE ALREADY PROVIDES SHORT-TERM PREDICTION, AND HAS THE INFRASTRUCTURE TO GENERATE LONG-TERM HINDCAST PREDICTIONS (UP TO 20 YEARS) AND PRELIMINARY QUALITY CONTROL AT THE FIELD AND FINAL QUALITY CONTROL EVALUATION BACK IN THE OFFICE. BASED ON MARKET RESEARCH OF SUCCESSFUL WATER-LEVEL MODELS THAT ARE USED IN OPERATIONS AND ARE INDEPENDENT FROM GEOID MODELS IN NOAA AND IN THE U.S. ARMY CORPS OF ENGINEERS. WE WERE NOT ABLE TO IDENTIFY ANY OTHER OPEN SOURCE OR COMMERCIAL OCEAN MODELS THAT CAN PROVIDE THE MARINE GRIDS WITH GEODETIC CONTROL ACCORDING TO THE OPERATIONAL

REQUIREMENTS NEEDED FOR TIDALLY-REFERENCED AERIAL OPERATIONS. THIS MODEL WAS DEVELOPED BY THE UNIVERSITY OF NOTRE DAME. THE TIDALLY-REFERENCED MARINE GRIDS FROM THE IMPROVEMENT WATER MODEL (WITH RESPECT TO THE ELLIPSOID) MUST BE COMPATIBLE IN ALL ASPECTS (FILE FORMAT, EPOCH, AND SPECIFIC TIDAL STAGE) WITH THE EXISTING OPERATIONAL FRAMEWORK USED FOR AERIAL OPERATIONS. THE ADCIRC MODEL IS UNIQUELY QUALIFIED TO MEET THESE

REQUIREMENTS BASED ON PROOF OF CONCEPT TESTING; INTEGRATION OF THE SHORT-TERM ADCIRC MODEL INTO THE NGS AERIAL OPERATIONS FRAMEWORK HAS BEEN SUCCESSFUL. THE EXPECTATION THAT AFTER MODIFICATIONS TO THE MODEL, THE INTEGRATION OF THE MODEL BACK TO THE FRAMEWORK WOULD BE STRAIGHT FORWARD. OTHER MODELS AVAILABLE, SUCH AS ROMS, SCHISM, AND FVCOM, DO NOT MEET THE REQUIREMENT. IN ORDER FOR THESE MODELS TO MEET THE TIDALLY-REFERENCE AERIAL OPERATIONS GLOBAL COVERAGE, MAJOR MODIFICATIONS (ESTIMATED ON THE ORDER OF YEARS OF RESEARCH WITH NO GUARANTEE FOR SUCCESS) WILL BE REQUIRED IN ORDER TO POTENTIALLY MEET THE ELEVATION MODEL SOURCE DATA AND THE RESOLUTION OF THE OUTPUT MARINE GRIDS. THIS TASK SUPPORTS AERIAL OPERATIONS THAT UPDATE MARINE NAVIGATIONAL CHARTS. BY UPGRADING THE OCEAN MODEL, IT WILL BE POSSIBLE TO CONDUCT THE FOLLOWING IN A TIMELY MANNER:

1) PREDICT MORE ACCURATELY THE TIDE WINDOWS FOR AERIAL IMAGERY IN ADVANCE FOR PROJECT PLANNING PURPOSES, AND TAKE INTO ACCOUNT LOCAL AND GLOBAL WATER LEVEL CHANGES;