NORS/NDACC UV-VIS Working Group Meeting Brussels, 04.07.2012

1. NORS/NDACC UV-VIS Working Group Meeting Brussels, 04.07.2012 NORS WP4: Advanced characterisation of NORS data products Andreas Richter, Folkard Wittrock and the WP4 Team Institute of Environmental Physics and Institute of Remote Sensing University of Bremen

2. Main Objectives of NORS WP4 “Ensure that the products provided by NORS are tailored so that the data can be used directly as validation data in the GMES atmospheric service (= GAS = MACC-II).” • Harmonization of data in terms of format and contents • Full characterisation of data with respect to integration volume, resolution, and sensitivity • Full description of uncertainties • Comparison to satellite data used for assimilation in GAS

3. Changes to current NDACC UV/vis approach Application of NDACC UV/vis data in GAS necessitates important changes in approach: Data of interest • Both stratospheric and tropospheric column amounts, profiles and surface concentrations Data formats • Common GEOMS HDF/netCDF format for all instruments and products Data provision • NRT or within a few weeks, not months / years Uncertainties • Detailed error budget needed for assimilation system Application • Automated use for daily validation

4. Structure of NORS WP4 Task 4.1 Data Formats Task 4.2 Information Content and Harmonization of Networks / Techniques Task 4.3 Uncertainties Task 4.4 Comparison to Satellite Observations

5. Structure of WP4 Task 4.1 Data Formats • Collection of current formats and contents • Iteration with data providers and GAS • Harmonisation of data files following GEOMS (Generic Earth Observation Metadata Standard) • Definition of new formats by all data providers for WP3 and WP7. If needed, development of conversion tools => GEOMS standards will beapplied ULg, UBremen, BIRA-IASB, INTA, UBern, KIT, CNRS, MPIC, UH, S&T

6. Structure of WP4 Task 4.2 Information Content and Harmonization of Networks / Techniques • Characterisation of vertical sensitivity and resolution • Analysis of horizontal displacement and averaging using different RTMs • Development of CH4 retrievals for NDACC and TCCON using overlapping windows • Standardisation of retrieval settings • Comparison of periods with parallel measurements of same quantity using different NORS techniques • Documentation of procedures and results U. Bremen, BIRA-IASB, INTA, UBern, KIT, CNRS, ULg, MPIC, UH

7. Structure of WP4 Task 4.3 Uncertainties • Collection of existing error assessments • Execution of additional sensitivity studies and theoretical uncertainty estimates • Consistent documentation of results • Recommendation for harmonized uncertainty reporting KIT, U Bremen, BIRA-IASB, INTA, UBern, CNRS, ULg, MPIC, UH

8. Structure of WP4 Task 4.4 Comparison to Satellite Observations • Evaluation of existing studies comparing satellite and NORS type data • Definition of validation approach and protocol • Execution of additional comparisons where possible and needed • Report on consistency INTA, UBremen, BIRA-IASB, INTA, UBern, KIT, CNRS, ULg, MPIC, UH

9. Summary • With NORS, a small subset of NDACC UV/vis stations will move to • Rapid data delivery • Use of GEOMS formats • Detailed measurement and error characterisation • Comparison between different NDACC measurement systems • As a result, data will be much more applicable for use in data assimilation and model / satellite data validation • It is foreseen to extend this approach to other stations after the project if resources are available => If successful, the NORS approach will substantially enhance the usability of NDACC UV/vis data and hopefully open an opportunity for future funding through link to the operational GAS service

10. Deliverables of WP4

11. Milestones of WP4