Abstract:Atmospheric nitrogen (N) deposition has been paid more and more attention due to the rapid increase of anthropogenic reactive N emissions. However, the information on atmospheric N deposition, especially the organic N deposition in Tibetan region, is still scarce. This paper reports the inputs and temporal variations of atmospheric organic N deposition in Linzhi area of Tibet from 2005 to 2007.
Monthly volume\|weighted concentrations of organic N varied from 0.15 to 0.53 mg/L and was 0.21mg/L on average. Significantly higher concentrations were found in July and August in 2006, which were up to 1.26 mg/L. In different seasons, organic N concentrations were higher in spring and summer, while lower in autumn and winter. Monthly averaged organic N deposition was 0.50 kg/hm2. Positive relationships between organic N deposition and precipitation in every rain event can be fitted by linear equations (r=0.46-0.77) in the three monitoring years. And relationship between organic N deposition and precipitation in different seasons can be fitted by a power equation (r=0.99). Large part of the organic N deposition was concentrated in the summer time, June and July, 2006 and June, July and September, 2007. Averaged deposition in summer is 0.93 kg/hm2, accounting for 46% of the whole year‘s deposition. Generally, organic N deposition accounted for 62% of the total N deposition in the whole monitoring period, which can not be neglected as an important composing of atmospheric nitrogen.rainfall; Tibet