Naslov
Reflection of light from the air/water interface covered with sea-surface microlayer

Autori
Kozarac, Zlatica ; Frka, Sanja ; Risović, Dubravko ; Moebius, Dietmar

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Book of Abstracts 1st International Meeting on Applied Physics, APHYS-2003 / Mendez-Vilas, A., Gonzalez-Mesa, J. A. - Badajoz : Departamento de Fisica, Universidad de Extremadura, 2003, 988-988

Skup
First International Meeting on Applied Physics ; APHYS-2003

Mjesto i datum
Badajoz, Španjolska, 13.10.2003. - 18.10.2003

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
sea-surface microlayer; reflection spectroscopy; Brewster angle microscopy

Sažetak
The sea-surface microlayer represents a boundary between the ocean and the atmosphere where important physicochemical, biological and photochemical processes take place. It is now widely recognized that it plays a major role in the exchange processes of gases, material and energy. Thus, the sea microlayer has an important role in the global climate and the overall balance of the Earth. Regarding optical properties of sea-surface the material known as chromophoric dissolved organic matter (CDOM), represents the predominant light absorbing part of dissolved organic material, which is a chemically complex and not very well defined mixture of anionic organic oligoelectrolytes containing phenolic surface active moieties. The enrichment in light absorbing material in the microlayers has significant effect on transformation processes at the interface and on the properties of interface itself. Recently we used reflection spectroscopy and Brewster angle microscopy (BAM) for physico-chemical characterization and optical visualization of sea-surface microlayers. Both techniques are based on reflection of the light from the air-water interface. The reflection spectra  R, are measured at normal incidence of light from the air/water interface. In Brewster angle microscopy (BAM) p-polarized light is incident on the air/water interface at the Brewster angle (53 ). In the case of the clean aqueous surface there is no reflection. In the presence of a thin layer reflection can be observed. BAM provides information about the homogeneity of the film, existence and formation of domains, phase transitions and adsorption of material from the aqueous phase. BAM images of considered microlayer were subject to fractal analysis using Box counting method in order to estimate the fractal dimension of a microlayer and its change during compression. We have established that the microlayer is indeed a fractal structure with dimension D=1.63. The gradual increase of fractal dimension proportional to compression is observed. The process ends in rather compact and homogenous non-fractal film with D =2.

Izvorni jezik
Engleski

Znanstvena područja
Fizika, Geologija, Kemija

POVEZANOST RADA