New perspectives on observation operators for atmospheric chemical data assimilation

Improved observation operators for atmospheric remote sensing data - describing the geographical offset and spread of the retrieved information from an observation - are presented and applied on sample atmospheric fields to illustrate the impact of smoothing and sampling issues on data comparisons. The use of those operators to reduce biases and noise in comparisons is demonstrated in the context of ground-based satellite validation, and possible applications in chemical data assimilation are discussed.