The DINAR (Development and Interpretation of Improved Nitrous Acid Retrievals) activity is a project funded by the European Space Agency (ESA) under the ATMOSPHERE SCIENCE CLUSTER - RESEARCH OPPORTUNITIES 2 - EXPRO+, which aims at further exploiting the capability of satellite instruments to measure nitrous acid (HONO), and advancing our understanding of HONO in the atmosphere.
The importance of nitrous acid (HONO) in atmospheric chemistry stems from its role as precursor of the OH radical. The latter is among the most important oxidizing molecules and controls the degradation of pollutants and greenhouse gases, and contributes to ozone formation and photochemical smog. Accurate representation of HONO sources is highly relevant to the modeling of climate and air quality. However, many uncertainties remain on the formation mechanisms, in part due to the lack of large-scale HONO measurements.