Two decades variations of nutrients in precipitation at the Qianliyan island, the western Yellow Sea.

Precipitation is of great significance in the transport and removal of atmospheric nutrients. For the sake of the acquaintance of nutrient level, deposition flux and secular trend of marginal sea precipitation, two decades (1997–2019) atmospheric investigations were conducted at the Qianliyan island, the western Yellow Sea. Overall, the annual average wet deposition fluxes of nitrate (NO 3 −), ammonium (NH 4 +), phosphate (PO 4 3−), silicate (SiO 3 2−), dissolved organic nitrogen (DON) and organic phosphorus (DOP) ranged 9.17–42.80, 13.50–41.44, 0.06–1.88, 0.07–5.56, 14.20–42.14 and 0.09–0.62 mmol·m−2·a−1, respectively. The annual average concentrations of NO 3 − in precipitation showed a monotonic rising trend, while that of SiO 3 2− showed a monotonic decreasing trend. From the long-term observation, it found an alleviation of acidic precipitation of the Yellow Sea under the policy controls of sulfur dioxide (SO 2) and nitrogen oxide (NO x) emissions. Meanwhile, effective control of sand-dust largely reduced precipitation SiO 3 2− concentration. Source also effected precipitation nutrients. Average concentrations of NO 3 −, NH 4 + and SiO 3 2− in precipitation from the ocean were lower than those from the northern arid area, while average concentrations of PO 4 3−, DON and DOP in precipitation from the ocean were higher than those from the northern arid area. Qianliyan precipitation brought rich dissolved inorganic nitrogen (DIN) over PO 4 3− to the ocean surface, which might alter the phytoplankton community succession ultimately. [Display omitted] • The annual average concentration of NO 3 − in precipitation showed a monotonic rising trend. • The annual average concentration of SiO 3 2− in precipitation showed a monotonic decreasing trend. • Effective control of sand-dust largely reduced precipitation SiO 3 2− concentration. • Nutrients levels in precipitation of different air-masses had distinct characteristics. • China's environmental protection and development affected Qianliyan precipitation nutrient levels. [ABSTRACT FROM AUTHOR]