LEADS THAT OCCUR IN REPEATING PATTERNS AND THE FORMATION OF COASTAL SHEAR ZONES CONTROL THE WINTER AND SPRING SEA-ICE DRIFT OPENING AND RIDGING. CLIMATE MODELS DO NOT ACCURATELY SIMULATE THESE PROCESSES AND HAVE LARGE VARIABILITY IN SIMULATING SEA-ICE CHANGE DRIFT AND LEAD OPENING. WE AIM TO IMPROVE THE RHEOLOGICAL COMPONENT OF SEA-ICE MODELS. THIS RHEOLOGY CONTROLS THE RELATIONSHIP BETWEEN WIND AND CURRENT FORCING ON THE ICE PACK AND ITS DEFORMATION WHICH CONTROLS THE ICE MOTION. WE HAVE IDENTIFIED ALONG-SHORE BOUNDARY CONDITIONS NEEDED FOR ACCURATE SIMULATION OF ICE DRIFT. IN LIGHT OF OUR RECENT ADVANCES IN OUR UNDERSTANDING OF THE MECHANICAL CONTROL OF ICE MOTION IN THE BEAUFORT GYRE WE ANTICIPATE MODEL IMPROVEMENTS WILL ALLOW CONSTRAINT OF FUTURE CLIMATE PROJECTIONS OF ARCTIC SEA ICE. WE PROPOSE TO USE SATELLITE AND AIRBORNE IMAGERY OF THE ARCTIC ICE PACK TO IDENTIFY THE MODES OF FAILURE THAT RESULT IN LEADS AND RIDGES FORMING. OUR PREVIOUS WORK HAS IDENTIFIED LEAD PATTERN GEOMETRY ALIGNS WITH MOHR-COULOMB THEORY (A RHEOLOGICAL MODEL). WE WILL CATALOG 38 YEARS OF CLEAR SKY SATELLITE SEA-ICE IMAGERY BY FRACTURE PATTERN AND USE ICE DRIFT AND DEFORMATION PRODUCTS TO FURTHER CLASSIFY BY MODE OF FAILURE (E.G. FAILURE IN TENSION SHEAR OR COMPRESSION). WE WILL EXTEND PREVIOUS WORK BY USING AVAILABLE ICE TRACKING PRODUCTS IN PARTICULAR THE RADARSAT GEOPHYSICAL PROCESSING SYSTEM (RGPS) ICE DEFORMATION PRODUCTS TO IDENTIFY COMPRESSIVE MODES OF FAILURE AND TO EXTEND BEYOND THE CLEAR SKY DATABASE. A SUBSET OF HIGH-RESOLUTION AIRBORNE IMAGERY FROM OPERATION ICE BRIDGE (OIB) WILL BE USED TO VERIFY IF PARTICULAR FAILURE MODES ARE FULLY RESOLVED IN LOWER-RESOLUTION SATELLITE IMAGERY. THE CATALOG OF CLASSIFIED FAILURE PATTERNS WILL BE SEARCHED FOR CASE STUDIES CAPTURED CLOSE TO THE TIME OF FAILURE. WE WILL PERFORM STRESS ANALYSIS ON THESE CASE STUDIES INITIALLY ASSUMING A MOHR-COULOMB RHEOLOGY. IDENTIFYING IF THERE ARE CONSISTENT PARAMETERS IN THE RHEOLOGICAL MODEL ACROSS THE CASE STUDIES OR IF THESE PARAMETERS VARY SEASONALLY BY ICE TYPE OR CONFINEMENT (APPLIED STRESS) ON THE ICE PACK. THIS INFORMATION WILL BE USED TO IDENTIFY APPROPRIATE RHEOLOGICAL MODELS FOR PACK ICE. WHICH WILL BE TESTED IN A STAND-ALONE SEAICE MODEL. OUR PREVIOUS WORK HAS IDENTIFIED THE IMPORTANCE OF THE LANDFAST ICE EDGE IN THE LOCATION OF LARGE SCALE LEAD PATTERNS. WE WILL TEST SUCH BOUNDARY CONDITIONS IN THE MODEL ALONG WITH EXPLORING HOW THE ICE STATE RESPONDS TO MODIFICATIONS TO RHEOLOGICAL MODELS OUR OBSERVATIONAL STUDY FINDS NECESSARY. WE ADDRESS THE NASA CRYOSPHERE PROGRAM LONG-TERM GOALS OF USING REMOTE SENSING PRODUCTS TO VALIDATE AND IMPROVE MODELS OF CHANGES IN SEA-ICE COVER. WE WILL IDENTIFY PHYSICAL PROPERTIES IN PARTICULAR MATERIAL PROPERTIES OF PACK ICE AND INCORPORATE THESE INTO SEA-ICE MODELS. THIS WORK IS NEEDED TO DETERMINE THE MECHANISMS CONTROLLING RECENT OBSERVED REDUCTIONS IN SEA ICE THICKNESS IN THE ARCTIC. WE UTILIZE NASA REMOTE SENSED AND OIB DATA TO IMPROVE MODELS OF SEA-ICE MOTION OPENING AND RIDGING. THIS WILL BETTER CONSTRAIN SEA-ICE DRIFT AND DEFORMATION AND ASSOCIATED FEEDBACKS IN CLIMATE PROJECTIONS. PROJECT OUTCOMES WILL INCLUDE MODEL IMPROVEMENTS TO BE SHARED WITH THE SEA-ICE COMMUNITY THROUGH PUBLICATIONS AND CONFERENCE PRESENTATION. BY CONSTRAINING THE MECHANICAL RESPONSE OF SEA ICE IN CLIMATE MODELS MODELERS WILL BE ABLE TO IMPROVE THE DYNAMIC COMPONENT OF SEA ICE MODELS. INTERACTING WITH THE CESM POLAR WORKING GROUP THE INTERNATIONAL ICE CHART WORKING GROUP AND THE SEA ICE PREDICTION NETWORK (GROUPS HUTCHINGS PARTICIPATES IN) FINDINGS WILL BE SHARED DIRECTLY WITH THOSE PROVIDING CLIMATE PROJECTIONS AND SHORT RANGE TO SEASONAL FORECASTS. IT IS ANTICIPATED THIS WILL RESULT IN IMPROVEMENTS (I) TO ICE DRIFT FIELDS IN CLIMATE MODELS (II) IN OUR ABILITY TO FORECAST THE LOCATIONS OF LEADS AND PRESSURED ICE AND (III) IN REPRESENTING RECENT AND PROJECTED SEA-ICE CHANGE.