Under this award the PIs will use a variety of paleoproductivity proxies to test the hypothesis that millennial changes in OMZ intensity in the Arabian Sea are directly related to changes in the intensity of upwelling-favorable winds associated with the SW Indian Ocean monsoon. To reconstruct export production on stadial/interstadial timescales in the Arabian Sea the PIs will measure at high-resolution the 230Th-derived accumulation rates of total organic carbon and total C37-alkenones, the authigenic uranium concentration, and the xs231Pa/xs230Th ratio. The alkenone unsaturation ratio (Uk. 37) will be used to reconstruct past sea-surface temperatures (SSTs) on stadial/interstadial timescales. Results of this work will improve understanding of 1) the teleconnections linking climate variability in the Arabian Sea to well-established records in the high-latitude North Atlantic region, 2) proxies of export production in sediments, and 3) the relationship between SST and the dynamics of the Indian Ocean monsoon system.
