Date: 03 June 2020

Time: 14:00 (GMT+3)

Speaker: Dr. Valeria Ibello

Title: Air-Sea carbon dioxide exchanges in the Mediterranean Sea: a focus on the North-eastern Levantine basin. 

Our webinar series is continuing with Dr. Valeria IBELLO! She will present her recent research on air-sea CO2 exchange, carbonate system and pH levels in the North-eastern Mediterranean. The talk will be given in English on the Zoom platform. Please note that there will be a limited number of spots available and the Institute members will be prioritized in case of overbooking. You can register via clicking the link below. After the registration, the meeting ID and password will be sent automatically via Zoom.

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Since the beginning of the industrial revolution, oceans have absorbed about 30% of the total CO2 emitted by human activities. Indeed, thanks to the carbonate system, the ocean has a large capability to buffer the increase of atmospheric CO2. As a consequence, the pH of the surface ocean is worldwide gradually decreasing, with variable intensity depending on many chemical, physical and biological factors. Measurements of air-sea CO2 fluxes, coupled with the assessment of carbonate system parameters along the water columns allow identifying the levels and risks of ocean acidification and predicting the effects on the ecosystem to eventually pave the way to mitigation actions.

Mediterranean Sea has been described to be nearly at equilibrium with the atmosphere in respect to CO2 exchange. Nevertheless, the scarcity of direct seasonal measurements in some areas, especially in the Eastern basin, prevents a precise assessment of the annual budget of air-sea CO2 fluxes on the basin scale. This study investigates the carbonate system and the air-sea CO2 exchange in the Northeast Mediterranean Sea in different seasons. Physical, chemical and biological processes have been explored to identify the main drivers of the CO2 fluxes. Results showed, as largely known from literature, an overall oligotrophy of the area, which limits the intensity of CO2 exchanges towards the ocean. However, in the winter season, primary production generally displayed higher rates driving a larger amount of CO2 to the ocean. Moreover, the surface winter cooling and the high intensity of wind stress observed during the sampling period increased the penetration of CO2 into the sea. In terms of pH levels, the values measured in the Northeastern Mediterranean resulted on average higher than the ones reported for the global Ocean, as already described by previous studies carried out in the Mediterranean Sea.

Key words: Northeastern Mediterranean, air-sea CO2 exchange, pH, carbonate system



Dr. Valeria Ibello is a marine biogeochemist. She obtained her M.S. in Marine Environmental Science from Università degli Studi di Napoli–Parthenope in 2001. From 2001 to 2008 she worked as research assistant at Consiglio Nazionale delle Ricerche (CNR-ISMAR), Trieste-Italy and then she continued at Istituto Nazionale di Oceanografia e di Geofisica Sperimentale (OGS), Trieste-Italy till 2010. She obtained her Ph.D in marine science in 2010 from University of Napoli. In 2011 she joined METU, Institute of Marine Science first with a postdoc fellowship, then from 2013 she is a lecturer in the department of Oceanography.

Her expertise focuses on biogeochemical cycles of carbon, nitrogen and phosphorus in the ocean. She explored the role on nitrogen fixation and dissolved organic matter in oligotrophic environments. Following multiple approaches combining models and field observations, she investigated carbon sequestration mechanisms, with a particular focus on organic matter aggregation and export from the euphotic zone to the deep layers. Currently, she teaches two courses about Geochemical Cycles and Ocean Acidification to master and Ph.D. students.

Her main efforts in the last years have concentrated on establishing the first marine laboratory of carbon dioxide and Ocean Acidification in Turkey. The new laboratory allows measurements of pH, total alkalinity and carbon dioxide with instruments at state of the art. Currently, her research focuses on the impacts of high CO2 levels on atmosphere-ocean interactions and marine carbonate chemistry in the East Mediterranean Sea. Multiple approaches combining field observations and satellite data targets the spatio-temporal variability of pH levels, the carbon dioxide fluxes and the underpinning physical and biological processes. The ultimate question is to assess the role of this part of the ocean as a source or sink of carbon dioxide for the atmosphere. These studies are supported by different national research projects (ASSET-TÜBİTAK, ATOMS-BAP and DEKOSIM).

Another project she has recently been involved in addressing the functioning of the marine microbial community. By identifying the community structure and the seasonal changes, the study aimed to understand the role of microbes in the biogeochemical cycle in the Mediterranean Sea. 

In the framework of a national monitoring project, she contributed to modelling studies addressing the biogeochemical and physical dynamics of coastal areas strongly impacted by anthropogenic factors. She is also actively involved in many outreach activities to increase awareness of the young generation on climate change and ocean acidification.