Fig. 2: Global and regional maps with the observation sites for δ15N of ambient NH3 (a-NH3), particulate NH4+ (p-NH4+), and precipitation NH4+ (w-NH4+) in East Asia, North America, and Europe.
From: Significant contributions of combustion-related sources to ammonia emissions
Maps were created by using ArcGIS version 10.5 (Esri Inc., USA). The base map was download from https://hub.arcgis.com/datasets/esri::world-countries-generalized.
