THE INDONESIAN THROUGHFLOW (ITF) IS THE ONLY CONDUIT LINKING THE TROPICAL PACIFIC TO THE INDIAN OCEAN. ITS VOLUME/HEAT TRANSPORT AND PROFILE WITH DEPTH VARY ACROSS A WIDE RANGE OF TEMPORAL SCALES THAT CAN BE LINKED TO THE NORTH EQUATORIAL CURRENT (NEC) BIFURCATION LATITUDE AND CLIMATE INDICES AND ASSOCIATED WIND FIELDS OF PACIFIC OCEAN. ITF VARIABILITY IS CLOSELY TIED TO EL NI O SOUTHERN OSCILLATION (ENSO) AND ITS OUTPUT HAS AN IMPACT ON THE INDIAN OCEAN HEAT AND FRESHWATER BUDGET AS WELL AS REGIONAL CLIMATE PATTERNS. DURING EL NI O ITF VOLUME TRANSPORT IN THE MAKASSAR STRAIT THERMOCLINE IS REDUCED AND THE WATER IS COOLER THAN DURING LA NI A WHEN THERE IS AN INCREASE IN WATER TRANSPORT IN THE WARMER UPPER 100 M. WATERS IN THE EASTERN TROPICAL INDIAN OCEAN AND WITHIN THE LEEUWIN CURRENT TO THE WEST OF AUSTRALIA HAVE SHOWN SIGNALS THAT CORRESPOND TO THIS VARIABILITY IN THE ITF. CHANGES IN SST ASSOCIATED WITH THE INDIAN OCEAN DIPOLE (IOD) AND INDIAN OCEAN BASIN MODE (IOB) HAVE BEEN SHOWN TO AFFECT THE STRENGTH OF THE ASIAN MONSOON. IT FOLLOWS THEREFORE THAT VARIABLE ITF INDUCED TEMPERATURE CHANGES IN THE EASTERN INDIAN OCEAN MAY ALSO AFFECT THE ASIAN MONSOON. ITF WATERS EVENTUALLY REACH THE AGULHAS CURRENT AND MAY EXIT THE INDIAN OCEAN THROUGH THE AGULHAS LEAKAGE. THIS INDIAN-ATLANTIC LINK MAY INFLUENCE ATLANTIC MERIDIONAL OVERTURNING CIRCULATION (AMOC) RAISING THE POSSIBILITY THAT ITF VARIABILITY COULD HAVE FAR REACHING EFFECTS. MANY STUDIES HAVE CONCENTRATED ON PACIFIC INFLOW INTO THE ITF BUT THE IMPACT OF THE ITF ON THE INDIAN OCEAN IS STILL POORLY UNDERSTOOD. THANKS TO THE COMBINED EFFORTS OF THE ARLINDO INSTANT AND NASA OCO PROGRAMS WE NOW HAVE A LONGER TIME SPAN OF MOORING DATA DEPICTING VELOCITY WITH DEPTH (ROUGHLY 1997-2015 2015-2017 EXPECTED) FROM THE MAKASSAR STRAIT THE PRINCIPAL THROUGHFLOW CHANNEL OF THE ITF. THE TIMING OF THIS MOORING OVERLAPS WITH THE ARGO FLOAT ARRAY (STARTED 2003) WHICH RESOLVES THE UPPER OCEAN TEMPERATURE SALINITY (T/S) STRATIFICATION ACROSS THE OCEAN BASINS. WE PROPOSE TO INVESTIGATE THE TEMPERATURE/SALINITY REACTION (AND TIME DELAY) WITHIN THE SURFACE AND THERMOCLINE STRATIFICATION OF THE TROPICAL INDIAN OCEAN TO ITF VARIABILITY DESCRIBED BY THE MAKASSAR STRAIT THROUGHFLOW USING THESE ARGO PROFILERS AS WELL AS SATELLITE DERIVED SEA SURFACE TEMPERATURE AND SALINITY. TO EXTEND THE TIME SCALE OF THE PROPOSED STUDY THE OBSERVED MAKASSAR TIME SERIES WILL BE RELATED TO WIND STRESS IN THE PACIFIC AND THE NEC BIFURCATION LATITUDE AND AN ITF TIME SERIES FROM 1979 ONWARD WILL BE RECONSTRUCTED. PRE-ARGO INDIAN OCEAN STRATIFICATION WILL BE INSPECTED WITH THE WOCE AND CLIVAR REPEAT SECTIONS. THIS STUDY WILL PROVIDE AN IMPORTANT TOOL AS WE CONTINUE TO RESOLVE THE INDIAN OCEAN HEAT/FRESHWATER BUDGET AND DETERMINE THE FORCES THAT DRIVE THE LARGE-SCALE OCEAN SYSTEM. AS WE FACE AN UNCERTAIN FUTURE WITH RESPECT TO A CHANGING GLOBAL CLIMATE THE LINKS INVESTIGATED HERE WILL HELP TO VALIDATE OCEAN CIRCULATION AND REGIONAL CLIMATE MODELS ESPECIALLY THOSE THAT FOCUS ON THE ASIAN MONSOON.