IGF::OT::IGF THE GOAL OF THE PROPOSED WORK IS TO STUDY THE GLOBAL EDDY-FIELD AT SCALES AS SMALL AS 20 KM US…

Public award description

IGF::OT::IGF THE GOAL OF THE PROPOSED WORK IS TO STUDY THE GLOBAL EDDY-FIELD AT SCALES AS SMALL AS 20 KM USING THE AVAILABLE LONG-TERM ALTIMETRIC RECORDS. BY ACCESSING THE HIGH SPATIAL RESOLUTION THAT IS PRESENT IN THE ALONG-TRACK ALTIMETER DATA, WE ARE ABLE TO RESOLVE THE IMPACTS OF EDDIES AT SCALES 2.5-10 TIMES SMALLER THAN IS POSSIBLE USING THE PRESENT GENERATION OF BLENDED MULTI-SATELLITE MAPS THAT ARE CURRENTLY WIDELY USED FOR EDDY-RELATED STUDIES. NEW RESEARCH HAS REVEALED AN EDDY FIELD - EXTENDING DOWN TO TENS OF KILOMETERS AND EVEN SMALLER-THAT IS CONSIDERABLY MORE ACTIVE, AND MORE IMPORTANT TO THE CLIMATE SYSTEM, THAN PREVIOUSLY BELIEVED. YET THE CURRENT GENERATION OF MAPPED PRODUCTS IS CREATED WITH THE EXPLICIT INTENT TO AVERAGE OVER RATHER THAN RESOLVE SUCH MESOSCALE AND SUBMESOSCALE EDDY STRUCTURES. THE FAVORED MAPPING METHOD IN SATELLITE ALTIMETRY-OPTIMAL INTERPOLATION OR OI - INITIALLY BECAME POPULAR IN OCEANOGRAPHY AT A TIME WHEN DATA DENSITY WAS A FRACTION OF WHAT IT IS TODAY. BECAUSE THERE WAS SO LITTLE DATA, IT WAS DESIRABLE TO AVERAGE OVER MESOSCALE FLUCTUATIONS IN ORDER TO MAP THE LARGE-SCALE FIELD. THERE IS NOW BOTH THE INTEREST AND THE DATA DENSITY TO SUBSTANTIALLY RESOLVE THE MESOSCALE; YET THE LARGE SMOOTHING SCALES OF 01 ARE STILL EMPLOYED. BY INCORPORATING MAPPING ACHIEVEMENTS TOGETHER WITH AN ALTERNATE APPROACH TO MAPPING EDDY KINETIC ENERGY, WE WILL PROTOTYPE A NEW CLASS OF GRIDDED ALTIMETRIC PRODUCTS WITH SMOOTHING SCALES THAT CHANGE ADAPTIVELY IN ORDER TO MAKE BEST USE OF ALL AVAILABLE DATA. THE VARIABILITY OBSERVED IN THESE NEW MAPS, PARTICULARLY THE EDDY KINETIC ENERGY, WILL THEN BE COMPARED WITH THE RESULTS FROM AN ALONG TRACK EDDY CENSUS IN ORDER TO ISOLATE THE CONTRIBUTIONS FROM EDDY-LIKE SEA SURFACE HEIGHT ANOMALIES HAVING PARTICULAR RADII, VELOCITIES OR ROSSBY NUMBERS, AND POLARITIES (CYCLONES VS. ANTICYCLONES). THIS APPROACH USES AN EVENT DETECTION ALGORITHM TO LOCATE INDIVIDUAL ANOMALIES IN THE ALONG-TRACK DATA, WHICH IN TURN THEN FORM THE BASIS FOR AN ESTIMATION OF THE LOCAL POPULATIONS AND PROPERTIES OF THE UNDERLYING EDDY FIELD USING AN INVERSE METHOD APPROACH. CAREFUL ATTENTION WILL BE GIVEN TO DISTINGUISHING THE DIFFERING CONTRIBUTIONS OF EDDIES VERSUS CURRENT MEANDERS OR EXCURSIONS WITHIN THE CONTEXT OF THIS CENSUS. THE NET RESULT WILL BE AN ABILITY TO ESTIMATE THE LOCAL CONTRIBUTIONS TO EDDY KINETIC ENERGY AND CIRCULATION ASSOCIATED DIRECTLY WITH COHERENT EDDIES, AND TO IDENTIFY THE REGIONS IN WHICH THESE ARE SIGNIFICANT. SINCE WE WILL BE WORKING WITH CONSIDERABLY HIGHER RESOLUTION THAN WAS POSSIBLE IN PREVIOUS STUDIES, NEW RESULTS CONCERNING THE NATURE OF THE EDDY FIELD AT THESE UNRESOLVED SCALES ARE ANTICIPATED. ANALYSIS TOOLS AND DATA PRODUCTS CREATED HERE ARE EXPECTED TO BE OF BROAD INTEREST AND WILL BE DISTRIBUTED TO THE COMMUNITY.