Fig. 3: Spatial distribution and trends of total reactive nitrogen and NH4T deposition. | Nature Geoscience

Fig. 3: Spatial distribution and trends of total reactive nitrogen and NH4T deposition.

From: Regime shift in secondary inorganic aerosol formation and nitrogen deposition in the rural United States

Fig. 3

a, The average annual total reactive nitrogen (Nr) deposition (dep) in the United States between 2010 and 2019. Solid, dashed and dotted lines show the boundaries of the areas within 50 km, 150 km and 300 km of an NH3-emission hotspot (Supplementary Text 2). The base map was obtained from Natural Earth. b–d, The 2010–2019 trends of annual total Nr deposition (b), NO3T deposition (c) and NH4T deposition normalized by NH3 emission (emis) (d) trends relative to the 2010 level (emis2010). The trends and relative annual change rates are determined using the Mann–Kendall test and Theil–Sen regression with a sample size of 10 (ref. 50). Numbers in the brackets are the 95% confidence intervals of the regressions (mean ± 1.96 s.d.). ‘↑’, ‘↓’ and ‘~’ indicate increasing trend, decreasing trend and no trend, respectively. *Statistically significant trend with P < 0.05 based on the Mann–Kendall test.

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