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| Identifier |
uch.chemistry.phd//2002kouvarakis |
| Title |
Όζον και αιωρούμενα σωματίδια στην ανατολική Μεσόγειο |
| Alternative Title |
Ozon and aerosols in the eastern Mediterranean atmospherie |
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Author
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Κουβαράκης, Γιώργος
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Thesis advisor
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Μιχαλόπουλος, Νικόλαος
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| Abstract |
The present work focuses οn the study of tropospheric ozone and aerosols in the Eastern Mediterranean atmosphere. The sampling was performed at Finokalia station located on the island of Crete from September 1996 to October 1999 During the sampling period, the annual ozone mean concentration was 52.0 ± 10.1 ppbv and ranged from 41.6 ± 2.5 ppbv to 63.2 ± 1.0 ppbv during winter and summer respectively. The annual mass of particulate matter was 34.9 ± 16.2 mgr·m-3. Sulfate is by far the main anion whereas calcium and ammonium are the main cations. A clear chloride and bromide deficit was observed on aerosols which can reach up to 80% of the expected concentrations. By comparison with previous work performed at Finokalia a clear inteannual variability of sulphate levels was found. On the other hand no clear tendency is observed for nitrate and ammonium. The 70 to 75% of wet deposition is constituted by ions of marine origin. In air masses of northern origin the pH of rain was 4.8 ± 0.7 while in air masses of southern origin the corresponding value was 7.1 ± 0.9. Contrary to aerosols no deficit has been observed for chloride ions, although a deficit was seen for bromide. The dry deposition of sulphur dioxide accounts for 85% of total sulphur deposition. The contribution of natural sulphur to the total sulphur budget can account up to 25% during the summer months. Our results show that the atmospheric deposition of DIN can account for up to 370% of the measured PON in the sediment traps indicating that atmospheric pathway alone can sufficiently account for the measured new nitrogen production. Based on the primary productivity induced by the imported DIN and the productivity of the South Eastern Mediterranean derived from in situ measurements a mean f ratio of 0.24 is calculated indicating that, from the N point of view, the Eastern Mediterranean can no longer be considered as among the most oligotrophic seas of the world. Other elements, most probably phosphorus (P) can account for the oligotrophic character of the Eastern Mediterranean Sea.
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| Language |
Greek |
| Issue date |
2002-07-01 |
| Collection
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School/Department--School of Sciences and Engineering--Department of Chemistry--Doctoral theses
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Type of Work--Doctoral theses
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| Views |
298 |
Όζον και αιωρούμενα σωματίδια στην ανατολική Μεσόγειο
