Chapter 9 – Photochemistry and the Cycling of Carbon, Sulfur, Nitrogen and Phosphorus

摘要: This chapter presents a discussion on photochemistry and the cycling of carbon, sulfur, nitrogen, Phosphorus. Dissolved organic matter (DOM) plays dominant role in absorption ultraviolet (UV) visible light open ocean. As DOM absorbance is regulated part by photobleaching processes, availability for photosynthesis penetration UV radiation within marine environment are influenced photochemical transformations. In addition to its control fields, strongly impacts biogeochemical biologically important elements surface seawater. By conversion into volatile species such as carbonyl sulfide, influences atmospheric chemistry climate. The illustrates an light-driven chemical reaction photic zone—that is, reduction trace metals iron, manganese, copper. these reduced quite different from their oxidized counterparts. Photochemical oxidation also produces suite free radicals other short-lived including superoxide anion, carbonate radical, singlet oxygen, hydroxyl di-bromide radical number poorly described excited state triplets. These much more reactive than corresponding diamagnetic ground expected influence biological processes sunlit waters. Furthermore, photolysis source or sink variety atmospherically gases that emitted ocean, some which affect Earth's radioactive balance. Concentrations—and hence emissions—of carbon monoxide (CO), dioxide (CO 2 ), sulfide (OCS), di-methyl (DMS) all partly through involving DOM.