透明胞外聚合颗粒物碳输运新途径

A new pathway for carbon transportation of transparent exopolymer particles

目前大家普遍认为,透明胞外聚合颗粒物(Transparent Exopolymer Particles,TEP)因其独特的凝聚效应导致碳通量向海底输出。但是,近几年的研究表明TEP不仅影响了碳沉降途径,其本身能够悬浮甚至向海水表层迁移,导致其在海洋微表层(SurfaceMicro-layer,SML)积累,最终显著影响海洋表层碳通量。TEP和其他颗粒物聚集形成凝聚物后,其运动趋势则由凝聚物中TEP的含量占比,即最终颗粒物密度所决定。一个新的值得注意的现象是,密度低的TEP通过与其他微粒聚合形成表面活性物质(Surface-active Substances,SAS),会在海洋–大气界面形成薄膜,显著影响海–气CO2交换通量,甚至对全球气候变化造成影响。

Previously, it was a broad consensus that transparent exopolymer particles (TEP) resulted in carbon flux output to the seabed due to its unique aggregation effect. Recently, some studies have shown that TEP could be retained in the water column and even ascend to the surface layer, which profoundly contributed to the elevated TEP concentrations and decreasing of air-sea carbon fluxes in the Surface Micro-layer (SML). The sinking or ascending of these TEP originated aggregates was finally depended on its density. TEP and further aggregated with other micro- particles became the surface-active substances in the SML, produce a thin layer film at the ocean-atmosphere interface, will heavily affect the exchange fluxes of sea-air CO2 and further the global climate changes.