Stöven, Tim (2011) Ventilation Processes of the Mediterranean Sea based on CFC-12 and SF6 measurements. (Diploma thesis), Christian-Albrechts-Universität, Kiel, Germany, 152 pp.

Preview

Text Stöven_Diplomarbeit.pdf - Published Version Available under License German copyright act UrhG. Download (8MB)

Abstract

The tracer data of CFC-12 and SF6 allow to determine a TTD ratio for most of the Eastern Mediterranean. The Ionian and Levantine Sea can be described by Δ/r ratios between 0:6-0:8. The Adriatic Sea has a high ratio of Δ/r = 1.2 for depths above 600m and a low ratio of Δ/r = 0.6 for the layers below. The tracer data of the Western Mediterranean as well as the Aegean and Cretan Sea does not fit into the 1D-TTD model. The reasons for the WMed are, that either the tracer couple does not fit into the 1D model or another TTD model must be chosen. The Δ/r ratio of the Aegean and Cretan Sea could not be determined due to the less significance of CFC-12 for young water masses. For all these sea areas a Δ/r ratio of 1.0 was set as mean ratio. Based on the tracer data, recent changes in the water column of the Mediterranean Sea were analyzed. The Eastern Mediterranean returns to a pre EMT (Eastern Mediterranean Transient) state with the Adriatic Sea as the major dense water source for the deep water of the Eastern Basin. The last dense water input from the Adriatic Sea can be verified in the bottom layer of the western Ionian Sea with CFC-12 concentrations > 230 ppt. The tracer minimum zone spreads out vertically and westwards with no intrusion of younger and denser water from the Aegean and Cretan Sea. The recent massive deep water formation of the Western Mediterranean (Western Mediterranean Transit) is shown by CFC-12 concentrations > 220 ppt. The exact spreading of the newly formed deep water could not be determined yet. Watermasses with characteristics of the Western Mediterranean deep water are entering the Tyrrhenian Sea via the channel between Sicily and Sardinia and are present at depths down to 2500m near the slope of Sicily. Based on the Δ/r ratios of the Eastern Mediterranean Sea, a new estimation of column inventories of anthropogenic carbon could be carried out. First calculations show that the column inventories have been underestimated by about 4.4% in comparison to Schneider et al. [2010].

Actions (login required)

View Item