Reviewing Global Estimates of Surface Reactive Nitrogen Concentration and Deposition Using Satellite Observation

Abstract

<p><strong>Abstract.</strong> Since the industrial revolution, human activities have dramatically changed the nitrogen (N) cycle in natural systems. Anthropogenic emissions of reactive nitrogen (N<sub>r</sub>) can return to the earth's surface through atmospheric N<sub>r</sub> deposition. Increased N<sub>r</sub> deposition may improve ecosystem productivity. However, excessive N<sub>r</sub> deposition can cause a series of negative effects on ecosystem health, biodiversity, soil, and water. Thus, accurate estimations of N<sub>r</sub> deposition are necessary for evaluating its environmental impacts. The United States, Canada and Europe have successively launched a number of satellites with sensors that allow retrieval of atmospheric NO<sub>2</sub> and NH<sub>3</sub> column density, and therefore estimation of surface N<sub>r</sub> concentration and deposition at an unprecedented spatiotemporal scale. Atmosphere NH<sub>3</sub> column can be retrieved from atmospheric infra-red emission measured by IASI, AIRS, CrIS or TES, while atmospheric NO<sub>2</sub> column can be retrieved from reflected solar radiation measured by GOME, GOME-2, SCIAMACHY, OMI, TEMPO, Sentinel and GEMS. In recent years, scientists attempted to estimate surface N<sub>r</sub> concentration and deposition using satellite retrieval of atmospheric NO<sub>2</sub> and NH<sub>3</sub> columns. In this study, we give a thorough review on recent advances of estimating surface N<sub>r</sub> concentration and deposition using the satellite retrievals of NO<sub>2</sub> and NH<sub>3</sub>, present a framework of using satellite data to estimate surface N<sub>r</sub> concentration and deposition based on recent works, and summarize the existing challenges for estimating surface N<sub>r</sub> concentration and deposition using the satellite-based methods. We believe that exploiting satellite data to estimate N<sub>r</sub> deposition has a broad and promising prospect.</p>