Atmosphere Ocean Science Friday Seminar

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Meridional Overturning with ECCO

Speaker: Tatsu Monkman

Location: Warren Weaver Hall 1314

Date: Friday, November 8, 2024, 4 p.m.

Synopsis:

Today I will be giving a presentation of a portion of my PhD thesis about the representation of the ocean’s large scale circulation in ECCO (a popular ocean reanalysis product). The ocean’s Meridional Overturning Circulation (MOC) plays a central role in Earth's climate, setting the stratification and large scale dynamics of the global ocean and controlling the abyssal storage of carbon and heat. However, several aspects of ECCO’s reconstructed MOC disagree with our contemporary theoretical understanding of the circulation’s structure. In fact, much of the upwelling in ECCO’s deep ocean is not associated with irreversible water mass transformations as is typically assumed. Instead, a dominant portion of the abyssal circulation in ECCO is associated with isopycnal volume tendencies, reflecting a deep ocean in a state of change. Although observational constraints are insufficient to unambiguously determine whether the simulated tendencies are real, there are indications that much of the trends in ECCO are spurious.