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CL4.12 | Tracking the Southern Hemisphere hydrographic frontal variability since the Pliocene
EDI
Tracking the Southern Hemisphere hydrographic frontal variability since the Pliocene
Convener: Deborah TangunanECSECS | Co-conveners: Mariem Saavedra-Pellitero, Elisa Malinverno, Iván Hernández-Almeida
The Subtropical, Subantarctic,and the Polar Fronts play a key role in connecting the cryosphere-hydrosphere-biosphere-atmosphere and climate variability between high-and low-latitude regions. The relative position of these South Hemisphere (SH) hydrographic fronts, both in the past and the present, regulates ocean-atmosphere CO2 exchange, deep-ocean carbon sequestration, and sea-ice extent, which have broad implications for the global climate. These hydrographic fronts are highly dynamic and shift positions in both short (seasonally) and longer timescales (thousands of years).

The late Neogene and the Quaternary is an interval of long-term cooling, but characterized by having several warmer than modern periods (e.g., warm Pliocene, “super interglacials” during the Late Pleistocene), which serve as analogues for the ongoing anthropogenic warming. During these intervals, it has been hypothesized that there was a large reorganization of the hydrographic and atmospheric fronts in the SH, which had consequences for ice-sheet build-up in Antarctica and ocean-atmosphere carbon cycling, with further implications for surface ocean dynamics and productivity. Characterization of these fronts using sedimentary records, located in mid-to-high latitudes in the SH allow us to understand the sensitivity and interconnection between Antarctic ice-sheets and carbon cycle to frontal shifts.

We encourage submissions of studies using quantitative or qualitative proxies (micropaleontological, geochemical, isotopic) sensitive to physical, chemical, and biological parameters for the surface ocean, as well as proxies for atmospheric changes, and proxy data assimilation. Ideally, sediment-based reconstructions should show orbital to millennial scale resolution in order to track shifts in frontal systems forced by different climatic processes. We target studies covering the last 5.3 Ma, particularly from (but not limited to) recent IODP sites in the SH (e.g., Expeditions 361, 382, 383) and legacy ODP sites (e.g., Expeditions 177, 189) drilled across these fronts, as well as modern studies (e.g., water, sediment trap, sediment core top samples) on multiple site transects in the SH.