Characterizing sampling biases in the trace gas climatologies of the SPARC Data Initiative

We characterize potential sampling biases in stratospheric trace gas climatologies of the Stratospheric Processes and Their Role in Climate (SPARC) Data Initiative using chemical fields from a chemistry climate model simulation and sampling patterns from 16 satellite-borne instruments.

The exercise is performed for the long-lived stratospheric trace gases O₃ and H₂O. Monthly sampling biases for O₃ exceed 10% for many instruments in the high-latitude stratosphere and in the upper troposphere/lower stratosphere, while annual mean sampling biases reach values of up to 20% in the same regions for some instruments. Sampling biases for H₂O are generally smaller than for O₃, although still notable in the upper troposphere/lower stratosphere and Southern Hemisphere high latitudes.