Dissolved organic materials in surface microlayers: Temporal and spatial variability and relation to sea state

Abstract

Microlayer samples were collected to assess the temporal and spatial variability of their dissolved organic materials (DOM). Dissolved organic carbon (DOC) was often enriched in microlayers but concentration differences between microlayers and bulkwaters were generally small. Ranges of DOC enrichments were large in oceanic samples. Enrichments diminished with increasing bulkwater DOC concentrations in coastal waters and were not influenced by wave states from Beaufort 0 to 4. Microlayer depletions of DOC occurred, but the removal processes responsible for them are unknown. UV‐absorbing phenolic fractions of microlayer DOM were consistently enriched, with the enrichments described by a partitioning relationship, and showed evidence of decreasing enrichment with increasing wave states. In general, over the temporal and spatial scales considered, microlayer DOM variabilities in clean surfaces were not greater than equivalent bulkwater variabilities.