This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 640276.
G2.19
G2.19 Line of sight and vertical averaging kernel are only approximations of the real 3D averaging kernel of a FTIR retrieval
Gap detailed description
The line of sight (LOS) is an important `first order’ characterization of the horizontal averaging for FTIR measurements. Tools exist to calculate the line of sight for individual FTIR measurement. The UVVIS GEOMS templates have introduced variables and can be transferred to the FTIR GEOMS template to store the LOS information. This is planned for the next FTIR GEOMS template update. Comparisons cannot yet account fully for the representativeness of the data, even though the LOS is used in such a comparison. To further characterize the horizontal averaging, a more detailed study of the 3D kernels should be issued.
Activities within GAIA-CLIM related to this gap
This gap is not addressed within GAIA-CLIM.
Gap remedy(s)
Remedy #1
Specific remedy proposed
Enhance the existing retrieval software packages so that the forward model allows non-uniform atmospheric states.
Measurable outcome of success
Updated retrieval software packages along with horizontal averaging kernels.
Achievable outcomes
Technological / organizational viability: medium
Indicative cost estimate: medium (< 1 million).
Relevance
Horizontal averaging and off site location of the probed airmasses is important for validation activities.
Timebound
5 years.
Gap risks to non-resolution
Identified future risk / impact |
Probability of occurrence if gap not remedied |
Downstream impacts on ability to deliver high quality services to science / industry / society |
Non-optimal validation results for gases and sites with strong spatial gradients. |
High |
Ambiguity in interpretation of the observed measurements, particularly in the prescence of strong gradients in the measured parameters. |