Can Nitrous Oxide be Measured Using Space Borne Ultraviolet Spectrometers?

Abstract:

The photolysis of nitrous oxide (HONO) by longwave UV radiation has hydroxyl radicals (OH) and nitric oxide (NO) as products. Since HONO accumulates in the troposphere during the night hours it plays a major role in the production of OH in the early morning during the wake-up tropospheric photochemistry. Therefore HONO concentrations have strong implications for the formation of ozone (O₃) and peroxyacyl nitrates (PANs) in the early hours of the morning.

Given the diurnal variation of HONO concentration, measurements from space borne ultraviolet spectrometers have been unsuccessful. The upcoming geostationary instruments devoted to monitor air quality, including TEMPO, will open possibilities to systematically make early morning measurements of HONO. Here we present an observation experiment to analyze the feasibility of HONO measurements from geostationary instruments using a combination of chemical transport models, in situ DOAS measurements of HONO in Madrid and radiative transfer calculations.