Εξειδίκευση τύπου :	Άρθρο σε επιστημονικό περιοδικό
Τίτλος:	Seasonal variations in dissolved organic matter composition using absorbance and fluorescence spectroscopy in the Dardanelles Straits – North Aegean Sea mixing zone
Δημιουργός/Συγγραφέας:	Pitta E. Zeri C. Tzortziou M. [EL] Μούσδης, Γεώργιος Α.[EN] Mousdis, George A. Scoullos M.
Εκδότης:	Elsevier Ltd
Ημερομηνία:	2017
Γλώσσα:	Αγγλικά
ISSN:	0278-4343
DOI:	10.1016/j.csr.2016.07.013
Περίληψη:	The Dardanelles Straits – North Aegean Sea mixing zone is the area where the less saline waters of Black Sea origin supply organic material to the oligotrophic Mediterranean Sea. The objective of this work was to assess the seasonal dynamics of dissolved organic matter (DOM) in this region based on the optical properties (absorbance and fluorescence). By combining excitation-emission fluorescence with parallel factor analysis (EEM-PARAFAC), four fluorescent components were identified corresponding to three humic – like components and one amino acid – like. The latter was dominant during all seasons. Chromophoric DOM (CDOM) and dissolved organic carbon (DOC) were found to be strongly coupled only in early spring when conservative conditions prevailed and the two water masses present (Black Sea Waters – BSW and Levantine Waters – LW) could be identified by their absorption coefficients (a300) and spectral slopes S275–295. In summer and autumn the relationships collapsed. During summer two features appear to dominate the dynamics of CDOM: i) photodegradation that acts as an important sink for both the absorbing DOM and the terrestrially derived fluorescent humic substances and ii) the release of marine humic like fluorescent substances from bacterial transformation of DOM. Autumn results revealed a source of fluorescent CDOM of high molecular weight, which was independent of water mass sources and related to particle and sedimentary processes. The removal of the amino acid-like fluorescence during autumn provided evidence that although DOC was found to accumulate under low inorganic nutrient conditions, dissolved organic nitrogenous compounds could serve as bacterial substrate.
Τίτλος πηγής δημοσίευσης:	Continental Shelf Research
Τόμος/Κεφάλαιο:	149
Σελίδες:	82-95
Θεματική Κατηγορία:	[EL] Φυσική και θεωρητική χημεία[EN] Physical and theoretical chemistry [EL] Φασματοσκοπία[EN] Spectroscopy
Λέξεις-Κλειδιά:	Carbon specific absorbance Chromophoric Dissolved Organic Matter (CDOM) Fluorescence indices Mediterranean Sea Parafac model Spectral slope
Αξιολόγηση από ομότιμους (peer reviewed):	Ναι
Κάτοχος πνευματικών δικαιωμάτων:	© 2016 Elsevier Ltd
Εμφανίζεται στις συλλογές:	Ινστιτούτο Θεωρητικής και Φυσικής Χημείας (ΙΘΦΧ) - Επιστημονικό έργο