Quantifying atmospheric nitrogen deposition through a nationwide monitoring network across China

Abstract

Abstract. A Nationwide Nitrogen Deposition Monitoring Network (NNDMN) containing 43 monitoring sites was established in China to measure gaseous NH3, NO2, and HNO3 and particulate NH4+ and NO3− in air and/or precipitation from 2010 to 2014. Wet/bulk deposition fluxes of Nr species were collected by precipitation gauge method and measured by continuous-flow analyzer; dry deposition fluxes were estimated using airborne concentration measurements and inferential models. Our observations reveal large spatial variations of atmospheric Nr concentrations and dry and wet/bulk Nr deposition. On a national basis, the annual average concentrations (1.3–47.0 μg N m−3) and dry plus wet/bulk deposition fluxes (2.9–83.3 kg N ha−1 yr−1) of inorganic Nr species are ranked by land use as urban > rural > background sites and by regions as north China > southeast China > southwest China > northeast China > northwest China > Tibetan Plateau, reflecting the impact of anthropogenic Nr emission. Average dry and wet/bulk N deposition fluxes were 20.6 ± 11.2 (mean ± standard deviation) and 19.3 ± 9.2 kg N ha−1 yr−1 across China, with reduced N deposition dominating both dry and wet/bulk deposition. Our results suggest atmospheric dry N deposition is equally important to wet/bulk N deposition at the national scale. Therefore, both deposition forms should be included when considering the impacts of N deposition on environment and ecosystem health.

Ground Ammonia Concentrations over China Derived from Satellite and Atmospheric Transport Modeling

“…Monthly NH 3 concentrations (in units of µg N m −3 ) were measured at 44 sites from 2010 to 2013 (Figure 1). The network mainly covered farmland sites but also included some grassland (two) and forest (four) sites across China [29,30]. The ground NH 3 concentrations in NNDMN were monitored using both DEnuder for Long-Term Atmospheric (DELTA) systems as well as Adapted Low-cost, Passive High Absorption (ALPHA) samplers [30,31].…”

Atmospheric dry and wet nitrogen deposition in agro-pastoral catchments of the China and Mongolia Altay

“…Although some N deposition studies have been conducted in agricultural and 68 pastoral areas (Luo et al 2003;Li et al 2012;Du et al 2014;Basto et al 2015;Huang 69 et al 2015;Liu et al 2015;Wasiuta et al 2015), little research has been conducted to 70 quantify atmospheric N deposition in the agro-pastoral zone. In China over 12 71 provinces comprising 160 towns and around 117 million people depend on this 72…”

“…Chinese cropland had the highest NH 3 (3.1μg N m -3 ) and NO 2 (3.8μg N m deposition of atmospheric reactive nitrogen (Nr; Liu et al, 2013).Since the 1980s 48 atmospheric Nr emissions have more than doubled in north and southeast China after 49 more than 30years of strong economic development (Liu et al 2013) and current 50 atmospheric Nr deposition are very high (Pan et al, 2012;Xu et al 2015). From the 51…”

River export of nutrients to the coastal waters of China: the MARINA model to assess sources, effects and solutions

“…Point sources are considered large polluters of P in rivers as a result of inadequate treatment (e.g., Bao et al 2006;Liu et al 2008a;Qu & Kroeze 2010;Qu & Kroeze 2012;Shen et al 2012;Xing & Zhu 2002). Some studies indicate the importance of atmospheric N deposition on land ) and on seas (Xu et al 2015) as well as of aquaculture (Biao & Kaijin 2007;Cao et al 2007;Liu et al 2009a). Direct N deposition on seas and aquaculture are point sources of nutrients in local areas of China.…”

“…Thus, local pollution may occur, such as polluted fish ponds from aquaculture and lakes in cities. In addition, direct N deposition on the sea was found to be an important polluter for specific coastal areas according to an experimental study of Xu et al (2015). Thus, I realize that these local sources of water pollution are important to consider in local assessments.…”