August 18-23: Goldschmidt Conference (Barcelona, Spain) (https://goldschmidt.info/2019/).
Theme: Chemistry of the Oceans and Atmosphere, Session: The Oceanic Particle Flux and its Cycling within the Deep Water Column (ID 10h) (https://goldschmidt.info/2019/program/programViewThemes).
Co-conveners: Maureen Conte (BIOS), Phoebe Lam (UCSC), Henry Ruhl (MBARI; NOC), and Rut Pedrosa Pamies (MBL).
The oceanic particle flux plays a major role in global elemental cycles, the ocean uptake of carbon dioxide, and the transfer of energy and matter to the deep ocean and sediments. The particle flux and its composition represent a dynamic balance between biological processes that generate large sinking particles in the upper ocean and particle cycling processes within the ocean interior that consume, modify and produce new sinking particles, including biologically-driven organic matter remineralization, particle aggregation/disaggregation, chemical scavenging, and authigenic mineral precipitation. New observational platforms, sampling methods and advances in chemical and molecular techniques (e.g., metabolomics, metagenomics, transcriptomics) allowing for expanded particle characterization are providing novel insights on particle flux transformations within the deep water column, including the depth evolution of particle-associated microbial communities and the scavenging of dissolved and suspended materials associated with biological reprocessing of flux materials. Synthesis and modeling studies are providing increased understanding of linkages between ecosystem structure and global patterns in surface export and flux transfer efficiency to the deep ocean. This multidisciplinary session will bring together scientists under research themes related to geochemistry, biology, oceanography, modeling and climatology to present the current status of our understanding of processes controlling the magnitude and composition of the oceanic particle flux, its attenuation and transformation with depth, and its coupling with associated biogeochemical cycles. Session presentations will describe novel findings and syntheses which, in turn, will highlight key knowledge gaps in the particle flux and its role in geochemical cycles.