La pasada semana, el alumno del Máster Interuniversitario en Oceanografía, David Curbelo Hernández presentó y defendió el Trabajo Final de Máster (TFM) titulado "Temporary evolution of the carbon dioxide system parameters in time series" cuyos tutores fueron Melchor González-Dávila y J. Magdalena Santana-Casiano.
En resumen, este trabajo estudió la variabilidad estacional y espacial de fugacidad y flujos de CO2 en el Noreste Atlántico, entre las Islas Canarias y el Estrecho de Gibraltar, en una región de transición entre el afloramiento de la costa Noroeste Africana y las aguas oligotróficas del giro subtropical del Atlántico Norte. El monitoreo y recolección de datos fue llevado a cabo entre febrero de 2019 y febrero de 2020 por el barco de observación voluntaria (VOS) RENATE P.
Este trabajo es parte del proyecto CanOA, enmarcado en el programa de investigación CanBIO, co-financiado por la Fundación Loro Parque y el Gobierno de Canarias.
Este trabajo de máster tamibén fue presentado previamente en el ISMS 2020, como comunicación oral en el evento SIQUIMAR.
El resumen del trabajo, en inglés, se
pesenta a continuación:
Oceans are important CO2 sinks that buffer the increase in their atmospheric concentration derived from anthropogenic emissions, which has produced alterations, not only in the Earth's climate, but also in marine biogeochemistry. One of the largest and most important ocean sinks, and therefore one of the most susceptible to disturbances, is the North Atlantic, so the study of the CO2 system in this basin is essential to understand and know to confront the Global Change.
This work has focused on the study of the seasonal variability of the
CO2 system and the air-sea CO2 exchange based on data collected by a voluntary
observatory ship (VOS) in the Northeast Atlantic, in a region of interest
between the Northwest African coastal upwelling and the oligotrophic waters of
the North Atlantic subtropical gyre between the Canary Islands and the Strait
of Gibraltar (~28-36ºN). The results show the seasonal and spatial variability
of the air-sea CO2 fluxes in this region, mainly driven by
variations in CO2 solubility in seawater controlled by
temperature. The system behaves as a source in summer with maximum average CO2 fluxes
around 2 mmol m-2d-1 in oceanic waters of the Canary
archipelago (2.147 ± 0.262 and 1.992 ± 0.358 mmol m-2d-1 on
the routes between Gran Canaria and Tenerife and between Tenerife and Lanzarote
respectively); and as a strong sink in the cold months, with minimum average CO2 fluxes
around -3 mmol m-2d-1 during winter throughout the
study region. Moreover, the averages of fCO2 are in
the range between ~420 µatm in summer and ~370 µatm in winter in all routes,
observing some longitudinal variability in inter-island routes and in the
Strait of Gibraltar associated with hydrographic differences; and an evident
latitudinal variability along the African coast related to regional differences
in the intensity of the coastal upwelling that explain the minimum values of fCO2 and
FCO2 determined in the region closest to Cape Ghir and in the
Strait of Gibraltar, where the system has behaved as a CO2 sink
in all seasons of the year. Finally, it was determined in this work an average
CO2 flux of -4.78 ± 0.6 Tg year-1, which indicates
that this area of the Northeast Atlantic behaves as a net CO2 sink.