Experimental enrichment of the sea surface microlayer from rising bubbles, the duality of breaking waves

Tiera-Brandy Robinson, Carl-von-Ossietzky Universität Oldenburg, Insitut für Chemie und Biologie des Meeres, Wilhelmshaven, Germany, Oliver Wurl, Carl-von-Ossietzky Universität Oldenburg, Institut für Chemie und Biologie des Meeres, Wilhelmshaven, Germany and Helge-Ansgar Giebel, University of Oldenburg, Institute for chemistry and biology of the marine environment, Oldenburg, Germany
Transparent exopolymer particles (TEP) act as a major transport mechanism for organic matter (OM) to the sea surface microlayer (SML) via bubble scavenging, and into the atmosphere via bubble bursting. However; little is known about the effects of bubble scavenging on TEP enrichment in the SML. This study examined the effects of several bubbling conditions and algae species on the enrichment of TEP in the SML. TEP enrichment in the SML was enhanced by bubbling, with a larger impact from bubbling rate than bubble size and increasing enrichment over time. Depth profiles showed that any TEP aggregates formed in the underlying water (ULW) were rapidly (<2 min) transported to the SML, and that TEP was entrained in the SML by bubbling. Species experiments determined that the presence of different phytoplankton species and their subsequent release of precursor material further enhance the effectiveness of TEP enrichment via bubble scavenging.