Evaluation of the Relationship Between IASI NH3R-I Total Column and Terrestrial Vegetation Conditions

Abstract

The IASI NH3R-I total column products provide a new perspective for monitoring global atmospheric ammonia (NH3) concentration. However, there are few evaluations on its correlation with vegetation conditions. In this paper, we use binning and resampling to evaluate the relationship between IASI-retrieved NH3 concentration and MODIS-retrieved vegetation indices from 2008 to 2016. As the results show, there is a significant positive correlation between NH3 concentration and vegetation conditions. The relationship has a clear intraannual pattern, while it has great spatial heterogeneity. Another finding is that nighttime NH3 observations generally have a better correlation with vegetation conditions. Still, deeper investigations and model simulations are needed to explain the mechanism behind this relationship and its spatial and temporal patterns.