Datensatz

Zusammenfassung

Quantifying the heat absorbed and released by the ocean is important in understanding the role of air-sea interactions in global climate. Estimates from reanalysis products are readily available but high-resolution (both temporal and spatial) observations are much less so. To investigate ocean heat budget and air-sea interactions on a local scale, we deployed four autonomous platforms east of Barbados as part of the Eurec4a campaign, January- February 2020, in a 10 km x 10 km region. 3 Seagliders undertook 581 dives yielding 1162 vertical ocean profiles, and our 5 m wave-powered surface vessel, Caravela, travelled more than 1000 km over ground. Variations in the surface mixed layer properties are described by Seaglider profiles of temperature and salinity. For example, the mixed layer depth varies over days to weeks between 11 m and 45 m. Turbulent microstructure from one Seaglider estimates the contribution of vertical mixing to the heat budget. Variations in upper ocean heat content are derived, and we test the extent to which local air-sea fluxes can account for changes in heat content. These fluxes are derived from Caravela’s in-situ measurements, including downwelling long-wave and short-wave radiation (long-wave observations varying from 370 W/m² to 490 W/m², with a peak solar radiation of 1440 W/m²), supplemented by fluxes from the ERA5 reanalysis. We also observe the diurnal cycle of the upper ocean heat content. In this presentation, we discuss the potential of these surface and subsurface platforms to derive an observationally-based heat budget on a local scale.