Unit:
Κατεύθυνση Φυσική ΠεριβάλλοντοςLibrary of the School of Science
Author:
Kourakos Dimitrios
Supervisors info:
Μποσιώλη Ελισάβετ, Επίκουρη Καθηγήτρια, Τμήμα Φυσικής, ΕΚΠΑ,
Σοφιανός Σαράντης, Αναπληρωτής Καθηγητής, Τμήμα Φυσικής, ΕΚΠΑ,
Σωτηροπούλου Γεωργία, Επίκουρη Καθηγήτρια, Τμήμα Φυσικής, ΕΚΠΑ
Original Title:
Παραμετροποίηση ροής οργανικών βιογενών εκπομπών από την επιφάνεια της θάλασσας στην Ανατολική Μεσόγειο
Translated title:
Parameterization of biogenic organic emissions fluxes from the sea surface in the Eastern Mediterranean
Summary:
The production of biogenic volatile organic compounds (BVOC) at the sea surface depends on biological activity and meteorological parameters. These compounds influx from the sea surface to the atmosphere, participate in photochemical reactions and contribute to photochemical pollution and the formation of secondary organic aerosols (SOAs) which in turn affect radiation, cloud formation and therefore climate. The estimation of BVOC sea to air fluxes has been mainly conducted in global scale models. The aim of this study is to estimate the sea surface concentrations of two important BVOCs, dimethyl sulfide (DMS) and isoprene, and their fluxes from the sea surface to the atmosphere of the Eastern Mediterranean in high spatial and temporal resolution. The methodology is based on literature parameterizations validated on global scale. The parameterizations for the sea-surface concentrations make use of satellite data of parameters such as chlorophyll-a (Chl-a) surface concentrations, sea surface temperature (SST), and Photosynthetically Available Radiation (PAR). For the fluxes, reanalysis data such as wind speed at 10 m, and ocean-model data such as euphotic zone depth and ocean mixed layer depth are also used. Our estimates are compared with measurements conducted in the marine area north of Heraklion Crete during the period September 1997 - August 1998 for DMS and February to October 2004 for isoprene. The sea-surface concentrations of DMS were estimated to be 0.30-1.53nM and the sea-to-air fluxes were 0.32-2.8 μmol m^(-2) d^(-1), in the period in the marine area near Finokalia, Crete. The sea-surface concentrations of isoprene were estimated to be 16.44 – 21.84 pM and the sea-to-air fluxes 10^7 – 2.4·10^7 molecules cm^(-2) s^(-1). The comparison with the measurements and climatologies shows that the estimates follow the seasonal variation of the measurements however they underestimate the summer values. The highest concentrations of DMS and isoprene are estimated in areas of high wind speeds and of increased chlorophyll. Our results indicate the need for further research and comparison with measurements from other sites in the Eastern Mediterranean.
Main subject category:
Science
Keywords:
biogenic, VOC, DMS, isoprene, ocean, fluxes, satellite data, chlorophyll
File:
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thesis_final.pdf
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File access is restricted until 2024-10-18.
