Abstract: NASA Langley Research Center is establishing a temporally- and spatially-ordered digital atlas of atmospheric chemistry fields, using data from historical and recent airborne missions and field campaigns, and from surface networks. Design of the atlas is based on fields, not point measurements, because of the differences in satellite vs. aircraft instrument fields of view and statistics. ... Information in the atlas will be searchable by geographical grid and time-of-year, and (where appropriate) by altitude. Because some of the input data will show the effects of ephemeral events such as volcanic eruptions, pollution plumes, and forest fires, those data will be tagged. This atlas will have widespread application for climate modeling, satellite validation, and the planning of future aircraft campaigns for atmospheric chemistry.