Size partitioning of particulate inorganic nitrogen species between the fine and coarse mode ranges and its implication to their deposition on the surface ocean

作者：Matsumoto Kiyoshi^*; Minami Hideki; Uyama Yukiko; Uematsu Mitsuo

来源：Atmospheric Environment, 2009, 43(28): 4259-4265.

DOI：10.1016/j.atmosenv.2009.06.014

• Atmospheric input
• Dry deposition flux
• Fixed nitrogen species
• Nitrate
• Ammonium

In order to discuss the dry deposition fluxes of atmospheric fixed nitrogen species, observations of aerosol chemistry including nitrate (NO3-) and ammonium (NH4 ) were conducted at two islands, Rishiri Island and Sado Island, over the Sea of japan. Although the atmospheric concentrations of particulate NH4 -N showed higher values than those of particulate NO3--N at both sites, the dry deposition fluxes of the particulate NO3--N were estimated to be higher than those of the particulate NH4 -N. This was caused by the difference of particle sizes between the particulate NO3- and NH4 ; NH4 was almost totally contained in fine particles (d < 2.5 mu m) with smaller deposition velocity, whereas NO3- was mainly contained in coarse particles (d > 2.5 mu m) with greater deposition velocity. Fine mode NO3- was strongly associated with fine mode sea-salt and mineral particles, of which higher concentrations shifted the size of particulate NO3- toward the fine mode range. This size shift would decrease the dry deposition flux of the fixed nitrogen species on coastal waters and accelerate atmospheric transport of them to the remote oceanic areas.

• 出版日期2009-9