| Autor: |
Schmitt-Kopplin, P., Liger-Belair, G., Koch, B. P., Flerus, R., Kattner, G., Harir, M., Kanawati, B., Lucio, M., Tziotis, D., Hertkorn, N., Gebefügi, I. |
| Předmět: |
|
| Zdroj: |
Biogeosciences Discussions; 2011, Vol. 8 Issue 6, p11767-11793, 27p |
| Abstrakt: |
Atmospheric aerosols impose direct and indirect effects on the climate system, for example, by adsorption of radiation in relation to cloud droplets size, on chemical and organic composition and cloud dynamics. The first step in the formation of primary marine aerosols, i.e., the transfer of dissolved organic matter from the marine surface into the atmosphere was studied, and we present a molecular level description of this phenomenon using high resolution analytical tools (Fourier transform ion cyclotron resonance = FT-ICR MS and NMR). We could experimentally confirm the chemo-selective transfer of natural organic molecules, especially of aliphatic compounds from the sur face water into the atmosphere via bubble bursting processes. Transfer from marine surface water to the atmosphere involves a chemical gradient governed by the physicochemical properties of the involved molecules when comparing elemental compositions and differentiating CHO, CHNO, CHOS and CHNOS bearing compounds. Typical chemical fingerprints of concentrated compounds were CHO and CHOS type of molecules, smaller molecules of higher aliphaticity and lower oxygen content and typical surfactants. A non-targeted mass spectrometric analysis of the samples showed that many of these molecules correspond to homologous series of oxo-, hydroxyl-, methoxy-, branched fatty acids and mono-, di- and tricarboxylic acids as well as monoterpenes and sugars. These surface active biomolecules were preferentially transferred from surface water into the atmosphere via bubble bursting processes to form a significant fraction of primary organic aerosols. This way of production of sea spray leaves a specific biological signature of the surface water in the corresponding lower atmosphere that can be transported laterally in the context of global cycling. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
|
