The CO2 system in the Mediterranean Sea: a basin wide perspective

[摘要] The Mediterranean Sea (MedSea) is considered a "laboratory basin" being anocean in miniature, suffering dramatic changes in its oceanographic andbiogeochemical conditions derived from natural and anthropogenic forces.Moreover, the MedSea is prone to absorb and store anthropogenic carbon dueto the particular CO₂ chemistry and the active overturning circulation.Despite this, water column CO₂ measurements covering the whole basinare scarce. This work aims to be a base-line for future studies about theCO₂ system space-time variability in the MedSea combining historic andmodern CO₂ cruises in the whole area. Here we provide an extensivevertical and longitudinal description of the CO₂ system variables(total alkalinity – TA, dissolved inorganic carbon – DIC and pH) along anEast-West transect and across the Sardinia-Sicily passage in the MedSea fromtwo oceanographic cruises conducted in 2011 measuring CO₂ variables ina coordinated fashion, the RV Meteor M84/3 and the RV Urania EuroFleets 11,respectively. In this sense, we provide full-depth and length CO₂distributions across the MedSea, and property-property plots showing in eachsub-basin post-Eastern Mediterranean Transient (EMT) situation with regardto TA, DIC and pH.

The over-determined CO₂ system in 2011 allowed performing the firstinternal consistency analysis for the particularly warm, high salinity andalkalinity MedSea waters. The CO₂ constants by Mehrbach et al. (1973)refitted by Dickson and Millero (1987) are recommended. The sensitivity ofthe CO₂ system to the atmospheric CO₂ increase, DIC and/or TAchanges is evaluated by means of the Revelle and buffer factors.

[学科分类] 海洋学与技术