Extended Data Fig. 3: The relationships between MDA8 ozone, satellite-based NO2 and HCHO TVCD in the five key regions for selected years during 2013–2021.
From: Sustained emission reductions have restrained the ozone pollution over China
MDA8 ozone are predicted with machine learning model in this work, and NO2 and HCHO TVCD are obtained from OMI products (see Methods of the article). The solid, dashed and dotted lines indicate the HCHO/NO2 ratio at 1, 2 and 4.
