Nitrous oxide (N₂O) represents a double threat to the Earth’s climate as a powerful greenhouse gas and first ozone-depletion gas, and is subject to increasing unprecedented concentrations due to human activities. Hence, demand for the scientific community to include global greenhouse budgets other than just carbon dioxide is growing. The N₂O intense outgassing in coastal upwelling systems represents over 20% of the global N₂O flux, despite covering only 3% of the world´s ocean. Hot-spots of N₂O emission are geographically constrained to Eastern Boundary Upwelling Systems (EBUS) in tropical and subtropical latitudes, but besides these low oxygen systems, the knowledge about the dynamics of the upwelling systems is relatively scarce. In this study we present novel data-base of the nitrous oxide monthly time series measurements in the Galicia Upwelling System, to assess the spatial and seasonal variability of N₂O concentrations and sea-air fluxes in this region and to investigate how it relates to the occurrence of upwelling. The results show that the upwelling area of Galicia behave as a net source of N₂O to the atmosphere, showing the increase from the shelf to the inshore of 50% in the northern rías, and up to 130% higher in the Ria de Vigo, where the upwelling have a notable impact on the N₂O emissions.

Primary Presenter: Mercedes de la Paz Arándiga, Instituto de Investigaciones Marinas- CSIC (mercedes.delapaz@iim.csic.es)

Authors:

Mercedes de la Paz, Instituto de Investigaciones Marinas-CSIC  ()

Fiz Pérez, Instituto de Investigaciones Marinas-CSIC  ()

Marta Alvarez, Instituto Español de Oceanografía  ()

Antonio Bode, C.O. Coruña-Instituto Español de Oceanografía  ()