Nutrients of atmospheric wet deposition from the Qianliyan Island of the Yellow Sea

Rainwater samples were collected at the Qianliyan Island of the Yellow Sea for the period of 2009-2010 and analysed for pH and nutrient concentrations (i.e. NH₄₊, NO_3- + NO_2-, SiO_32- and PO_43-). The results showed that the pH values in 58% samples ranged from 5.6 to 7.0, dominated by neutral depositions. Concentrations of nutrients had seasonal variations, higher in spring and winter but relatively low in summer and autumn. Based on comparison of inorganic nitrogen concentrations in rainwater at different regions, the air-mass back-trajectory and annual variations, atmospheric wet depositions over the Yellow Sea were affected by the anthropogenic emissions as well as sand-dust storms. Furthermore, the historical overview of existing data indicated that atmospheric dry and wet depositions of NH₄₊-N, DI(NO_3- + NO_2-), SiO_32--Si and PO_43--P account for 87%, 47%, 3% and 53%, respectively, of total terrestrial (i.e. atmospheric depositions and riverine influx) input. Rainfall in this region can dramatically increase surface water nutrient level that enhance the primary productivity.