Non-steady-state biological removal of atmospheric particles from Mediterranean surface waters
Non-steady-state biological removal of atmospheric particles from Mediterranean surface waters
复制标题
从地中海地表水中非稳态生物去除大气颗粒
作者：
P. Buat;J. Davies;E. Remoudaki;J. Miquel;G. Bergametti;C. Lambert;U. Ezat;C. Quétel;J. Rosa;S. Fowler
最近有人提出，矿物气溶胶颗粒的沉积，主要是在零星但强烈的事件期间从非洲运来的1,2，可能对地中海的地球化学和沉积学产生深远的影响1-3。在开阔海域进行的几项研究表明，这些半径一般小于5 μm的颗粒，与生物包装产生的大型有机颗粒一起，在几周内就能从地表水中去除。在这里，我们报告了从沉积物捕集器获得的200米深度的大气输入和水柱参与通量的时间序列测量数据，这些数据表明这种生物控制在地中海西北部水域也普遍存在。在短时间尺度上，上层水柱的浓度和通量在沙尘输送和沉积事件后显著增加，响应时间约为一周。在评估脉冲大气输入对水柱中微粒微量元素浓度和通量的影响时，必须考虑到这种非稳态行为。
IT has recently been suggested that the deposition of mineral aerosol particles, primarily transported from Africa during sporadic but intense events1,2, may have a profound influence on the geochemistry and the sedimentology of the Mediterranean Sea1-3. Several studies in the open ocean4-7 have shown that such particles, with radii generally less than 5 μm, are removed from the surface waters within a few weeks, together with large organic particles produced by biological packaging7. Here we report data from time-series measurements of both atmospheric inputs and water-column participate fluxes at 200m depth obtained from sediment traps, which show that such a biological control also prevails in northwestern Mediterranean waters. On short time-scales, concentrations and fluxes in the upper water column can increase significantly following dust transport and deposition events, with a response time of the order of one week. Such non-steady-state behaviour must be taken into account when assessing the impact of pulsed atmospheric inputs on particulate trace element concentrations and fluxes in the water column.