Changes in wet nitrogen deposition in the United States between 1985 and   2012

doi:10.1088/1748-9326/9/9/095004

CORC > 北京大学 > 城市与环境学院

	Changes in wet nitrogen deposition in the United States between 1985 and 2012
	Du, Enzai ; de Vries, Wim ; Galloway, James N. ; Hu, Xueyang ; Fang, Jingyun
刊名	environmental research letters
	2014
关键词	nitrogen deposition ammonium:nitrate ratio Mann-Kendall test regional Kendall test PRECIPITATION CHEMISTRY AMMONIA EMISSIONS REACTIVE NITROGEN REDUCED NITROGEN CRITICAL LOADS TRENDS ENVIRONMENT FUTURE USA
DOI	10.1088/1748-9326/9/9/095004
英文摘要	The United States (US) is among the global hotspots of nitrogen (N) deposition and assessing the temporal trends of wet N deposition is relevant to quantify the effectiveness of existing N regulation policies and its consequent environmental effects. This study analyzed changes in observed wet deposition of dissolved inorganic N (DIN = ammonium + nitrate) in the US between 1985 and 2012 by applying a Mann-Kendall test and Regional Kendall test. Current wet DIN deposition (2011-2012) data were used to gain insight in the current pattern of N deposition. Wet DIN deposition generally decreased going from Midwest > Northeast > South > West region with a national mean rate of 3.5 kg N ha(-1) yr(-1). Ammonium dominated wet DIN deposition in the Midwest, South and West regions, whereas nitrate and ammonium both contributed a half in the Northeast region. Wet DIN deposition showed no significant change at the national scale between 1985 and 2012, but profound changes occurred in its components. Wet ammonium deposition showed a significant increasing trend at national scale (0.013 kg N ha(-1) yr(-2)), with the highest increase in the Midwest and eastern part of the South region. Inversely, wet nitrate deposition decreased significantly at national scale (-0.014 kg N ha(-1) yr(-2)), with the largest reduction in the Northeast region. Overall, ratios of ammonium versus nitrate in wet deposition showed a significant increase in all the four regions, resulting in a transition of the dominant N species from nitrate to ammonium. Distinct magnitudes, trends and patterns of wet ammonium and nitrate deposition suggest the needs to control N emissions by species and regions to avoid negative effects of N deposition on ecosystem health and function in the US.; Environmental Sciences; Meteorology & Atmospheric Sciences; SCI(E); EI; 0; ARTICLE; duez@pku.edu.cn; 9; 9
语种	英语
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/322191]
专题	城市与环境学院
推荐引用方式 GB/T 7714	Du, Enzai,de Vries, Wim,Galloway, James N.,et al. Changes in wet nitrogen deposition in the United States between 1985 and 2012[J]. environmental research letters,2014.
APA	Du, Enzai,de Vries, Wim,Galloway, James N.,Hu, Xueyang,&Fang, Jingyun.(2014).Changes in wet nitrogen deposition in the United States between 1985 and 2012.environmental research letters.
MLA	Du, Enzai,et al."Changes in wet nitrogen deposition in the United States between 1985 and 2012".environmental research letters (2014).