scholarly journals Characterization and longitudinal study of aerosol particles using a synergy of lidar techniques and passive remote sensing methods in the Mediterranean basin

2020 ◽  
Author(s):  
Ουρανία Σουπιωνά
Keyword(s):  
Remote Sensing ◽  
Longitudinal Study ◽  
Mediterranean Basin ◽  
Aerosol Particles ◽  
Light Detection And Ranging ◽  
Light Detection ◽  
Passive Remote Sensing ◽  
The Mediterranean ◽  
Remote Sensing Methods ◽  
The Mediterranean Basin

H παρούσα Διδακτορική Διατριβή έχει ως αντικείμενο τη μελέτη των τροποσφαιρικών αερολυμάτων με τη χρήση επίγειων και δορυφορικών τεχνικών, για την ανάκτηση των οπτικών ιδιοτήτων των αιωρούμενων σωματιδίων και την στατιστική ανάλυσή τους. Παράλληλα, εφαρμόζονται μαθηματικοί αλγόριθμοι για την ανάκτηση των μικροφυσικών τους ιδιοτήτων, καθώς και γίνεται χρήση προγνωστικών μοντέλων για ανάκτηση επιπλέον πληροφοριών, όπως ο προσδιορισμός της πηγής προέλευσης των αιωρούμενων σωματιδίων, αλλά και η επίδρασή τους στο ατμοσφαιρικό ενεργειακό ισοζύγιο. Στο πρώτο κεφάλαιο (Κεφάλαιο 1) περιλαμβάνεται το θεωρητικό υπόβαθρο των ατμοσφαιρικών αερολυμάτων, ο ρόλος τους στην ατμοσφαιρική Φυσική, καθώς και οι διάφοροι τύποι αερολυμάτων, δίνοντας τη συνολική εικόνα του πεδίου μελέτης. Στο Κεφάλαιο 2 αναφέρονται οι θεμελιώδεις πτυχές της ατμοσφαιρικής Φυσικής και της Οπτικής, με έμφαση στους μηχανισμούς αλληλεπίδρασης του φωτός με τα ατμοσφαιρικά στοιχεία (αερολύματα και μόρια). Οι τεχνικές τηλεπισκόπησης αερολυμάτων που έχουν χρησιμοποιηθεί ευρέως σε αυτή τη διατριβή παρουσιάζονται στο Κεφάλαιο 3, μαζί με λοιπά διαθέσιμα όργανα που χρησιμοποιήθηκαν για τη λήψη δεδομένων των προς εξαγωγή αποτελεσμάτων. Συγκεκριμένα παρουσιάζεται η τεχνική light detection and ranging (lidar), καθώς και τα διάφορα στάδια επεξεργασίας των σημάτων lidar. Τα ατμοσφαιρικά προγνωστικά μοντέλα αλλά και εργαλεία που αξιοποιούν δορυφορικές μετρήσεις και χρησιμοποιήθηκαν για την ενίσχυση των αποτελεσμάτων μας παρουσιάζονται εν συντομία στο Κεφάλαιο 4. Η περιεκτική ανάλυση των αποτελεσμάτων παρουσιάζεται στο Κεφάλαιο 5, ενώ τα συμπεράσματα παρατίθενται στο Κεφάλαιο 6, που αποτελεί το τελευταίο κεφάλαιο αυτής της Διατριβής.

SMOS-based estimation and validation of Total Alkalinity in the Mediterranean basin

2020 ◽  
Author(s):  
Roberto Sabia ◽  
Estrella Olmedo ◽  
Giampiero Cossarini ◽  
Aida Alvera-Azcárate ◽  
Veronica Gonzalez-Gambau ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Mediterranean Sea ◽  
Mediterranean Basin ◽  
Sea Surface ◽  
Sea Surface Salinity ◽  
Total Alkalinity ◽  
Surface Salinity ◽  
Carbonate System ◽  
The Mediterranean ◽  
The Mediterranean Basin

<p>ESA SMOS satellite [1] has been providing first-ever Sea Surface Salinity (SSS) measurements from space for over a decade now. Until recently, inherent algorithm limitations or external interferences hampered a reliable provision of satellite SSS data in semi-enclosed basin such as the Mediterranean Sea. This has been however overcome through different strategies in the retrieval scheme and data filtering approach [2, 3]. This recent capability has been in turn used to infer the spatial and temporal distribution of Total Alkalinity (TA - a crucial parameter of the marine carbonate system) in the Mediterranean, exploiting basin-specific direct relationships existing between salinity and TA.</p><p>Preliminary results [4] focused on the differences existing in several parameterizations [e.g, 5] relating these two variables, and how they vary over a seasonal to interannual timescale.</p><p>Currently, to verify the consistency and accuracy of the derived products, these data are being validated against a proper ensemble of in-situ, climatology and model outputs within the Mediterranean basin. An error propagation exercise is also being planned to assess how uncertainties in the satellite data would translate into the final products accuracy.</p><p>The resulting preliminary estimates of Alkalinity in the Mediterranean Sea will be linked to the overall carbonate system in the broader context of Ocean Acidification assessment and marine carbon cycle.</p><p>References:</p><p>[1] J. Font et al., "SMOS: The Challenging Sea Surface Salinity Measurement From Space," in Proceedings of the IEEE, vol. 98, no. 5, pp. 649-665, May 2010. doi: 10.1109/JPROC.2009.2033096</p><p>[2] Olmedo, E., J. Martinez, A. Turiel, J. Ballabrera-Poy, and M. Portabella,  “Debiased non-Bayesian retrieval: A novel approach to SMOS Sea Surface Salinity”. Remote Sensing of Environment 193, 103-126 (2017).</p><p>[3] Alvera-Azcárate, A., A. Barth, G. Parard, J.-M. Beckers, Analysis of SMOS sea surface salinity data using DINEOF, In Remote Sensing of Environment, Volume 180, 2016, Pages 137-145, ISSN 0034-4257, https://doi.org/10.1016/j.rse.2016.02.044.</p><p>[4] Sabia, R., E. Olmedo, G. Cossarini, A. Turiel, A. Alvera-Azcárate, J. Martinez, D. Fernández-Prieto, Satellite-driven preliminary estimates of Total Alkalinity in the Mediterranean basin, Geophysical Research Abstracts, Vol. 21, EGU2019-17605, EGU General Assembly 2019, Vienna, Austria, April 7-12, 2019.</p><p>[5] Cossarini, G., Lazzari, P., and Solidoro, C.: Spatiotemporal variability of alkalinity in the Mediterranean Sea, Biogeosciences, 12, 1647-1658, https://doi.org/10.5194/bg-12-1647-2015, 2015.</p><p> </p><p> </p>

Air Pollution and Climate

2009 ◽  
Author(s):  
Jos Lelieveld
Keyword(s):  
Air Pollution ◽  
Nitrogen Oxides ◽  
Solar Radiation ◽  
Greenhouse Gases ◽  
Radiative Forcing ◽  
Mediterranean Basin ◽  
Aerosol Particles ◽  
Transport Pathways ◽  
The Mediterranean ◽  
The Mediterranean Basin

It has long been known that atmospheric pollutants can be hazardous to human health and ecosystems. This includes effects from episodic peak levels as well as the long-term exposure to relatively moderate concentration enhancements. Environmental issues related to air pollution include acidification, mostly by the strong acids from sulphur and nitrogen oxides, eutrophication by the deposition of reactive nitrogen compounds, the reduction of air quality by photo-oxidants and particulate matter, and the radiative forcing of climate by increasing greenhouse gases and by aerosol particles. Many air pollutants are photochemically formed within the atmosphere from emissions by traffic, energy generation, industry, the burning of wastes, and forest fires. The Mediterranean basin in summer is largely cloudfree, and the relatively intense solar radiation promotes the photochemical formation of ozone (O3) and peroxyacetyl nitrate (PAN); O3 being health hazardous at levels in excess of about 100 μg/m3. Ozone is formed in the lower atmosphere as a by-product in the oxidation of reactive carbon compounds such as carbon monoxide (CO) and non-methane volatile organic compounds (NMVOC), catalysed by nitrogen oxides (NOx ≡ NO + NO2). In summer, notably the period from June to August, transport pathways of air pollution near the earth’s surface are typically dominated by northerly winds, carrying photo-oxidants and aerosol particles from Europe into the Mediterranean basin. Aerosol particles with a diameter of less than ∼10 μm (PM10) can have adverse health effects at a concentration of about 30 μg/m3 or higher. The fine mode particles (<2 μm diameter) are mostly composed of sulphates, nitrates, and particulate organic matter, whereas the coarse mode particles (≥2 μm) often contain substantial amounts of sea salt, Saharan dust (Chapter 14), and other mineral components. The aerosols can form widespread hazes that scatter and absorb solar radiation, thus reducing downward energy transfer and surface heating. Increased aerosol scattering causes a negative radiative forcing of climate (cooling tendency), to be weighted against the positive radiative forcing (warming tendency) by increasing greenhouse gases such as carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), halocarbons, and tropospheric ozone (IPCC 2001).

Piracy and Law in the Ottoman Mediterranean

2017 ◽  
Author(s):  
Joshua M. White
Keyword(s):  
International Law ◽  
Mediterranean Basin ◽  
Islamic Law ◽  
Comprehensive Examination ◽  
Legal Space ◽  
The Mediterranean ◽  
First Time ◽  
Eastern Half ◽  
The Mediterranean Basin

This book offers a comprehensive examination of the shape and impact of piracy in the eastern half of the Mediterranean and the Ottoman Empire’s administrative, legal, and diplomatic response. In the late sixteenth and seventeenth centuries, piracy had a tremendous effect on the formation of international law, the conduct of diplomacy, the articulation of Ottoman imperial and Islamic law, and their application in Ottoman courts. Piracy and Law draws on research in archives and libraries in Istanbul, Venice, Crete, London, and Paris to bring the Ottoman state and Ottoman victims into the story for the first time. It explains why piracy exploded after the 1570s and why the Ottoman state was largely unable to marshal an effective military solution even as it responded dynamically in the spheres of law and diplomacy. By focusing on the Ottoman victims, jurists, and officials who had to contend most with the consequences of piracy, Piracy and Law reveals a broader range of piratical practitioners than the Muslim and Catholic corsairs who have typically been the focus of study and considers their consequences for the Ottoman state and those who traveled through Ottoman waters. This book argues that what made the eastern half of the Mediterranean basin the Ottoman Mediterranean, more than sovereignty or naval supremacy—which was ephemeral—was that it was a legal space. The challenge of piracy helped to define its contours.

Unfinished and Less Authored Texts

2018 ◽  
Author(s):  
Matthew D. C. Larsen
Keyword(s):  
Late Antiquity ◽  
Mediterranean Basin ◽  
Written Texts ◽  
The Mediterranean ◽  
The Mediterranean Basin ◽  
Jewish Writers

The concept of textual unfinishedness played a role in a wide variety of cultures and contexts across the Mediterranean basin in antiquity and late antiquity. Chapter 2 documents examples of Greek, Roman, and Jewish writers reflecting explicitly in their own words about unfinished texts. Many writers claimed to have written unfinished texts on purpose for specific cultural reasons, while others claimed to have written texts that slipped out of their hands somehow with their permission.

The Alphabet and its Legacy

2019 ◽  
pp. 240-255
Author(s):  
Madadh Richey
Keyword(s):  
Mediterranean Basin ◽  
Technological Development ◽  
Greek Language ◽  
Writing Systems ◽  
Present Contribution ◽  
Generative Power ◽  
The Mediterranean ◽  
Alphabetic Writing ◽  
The Mediterranean Basin

The alphabet employed by the Phoenicians was the inheritor of a long tradition of alphabetic writing and was itself adapted for use throughout the Mediterranean basin by numerous populations speaking many languages. The present contribution traces the origins of the alphabet in Sinai and the Levant before discussing different alphabetic standardizations in Ugarit and Phoenician Tyre. The complex adaptation of the latter for representation of the Greek language is described in detail, then some brief attention is given to likely—Etruscan and other Italic alphabets—and possible (Iberian and Berber) descendants of the Phoenician alphabet. Finally, it is stressed that current research does not view the Phoenician and other alphabets as inherently simpler, more easily learned, or more democratic than other writing systems. The Phoenician alphabet remains, nevertheless, an impressive technological development worthy, especially by virtue of its generative power, of detailed study ranging from paleographic and orthographic specifications to social and political contextualization.

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