Under the direction of the Chair of INFCOM/SC-MINT, the Expert Team on Surface- and Sub-surface Measurement (ET-SSM) shall undertake tasks and provide advice on and support for the implementation of the WIGOS framework and the priority activities of the WIGOS operational phase 2020-2023, in accordance with the SC-MINT Terms of Reference for surface and sub-surface measurements1; in particular:
1. Develop and maintain guidance material, best practices, standards and specifications related to surface/sub-surface measurements and related technologies to meet requirements from Members. (Specific needs were identified for measurement of soil moisture, low-cost AWSs, generic tender specifications.)
2. Develop and maintain standards related to the ET activities, and related guidance on their use (for example, Siting Classification and Measurement Quality Classification). Contribute to the identification and development of standards in co-operation with other international standardization organizations, such as ISO and BIPM, where appropriate.
3. Regularly review, and update as required, relevant parts of WMO-No. 8 and other WMO guides related to surface/sub-surface measurements and instrumentation and ensure consistency with other WIGOS regulatory and guidance material.
4. Review and publish performance results and recommendations relating to state-of-the-art operational measurement technologies, their calibration and measurement methods and their required supporting infrastructure.
5. Monitor, investigate and report on the performance of emerging measurement technologies and techniques, including low cost technologies.
6. Promote developments related to instruments, automated measurement techniques and methods of manual observation of surface/sub-surface conditions suitable for all Members, including the least developed countries, in liaison with the Association of Hydro-Meteorological Equipment Industry, National Meteorological and Hydrological Services and other relevant scientific institutions.
7. Review outcomes of the Testbed(s) and/or Lead Centre(s) (TB/LC) assigned to this Expert Team, and in collaboration with the TB/LC(s), coordinate timely inclusion of guidance material on best practices and of training material in WMO publications.
8. Review and make proposals on development of more robust instruments with greater resilience to extreme weather and/or climate conditions, and instruments with increased measuring range.
9. Monitor, review and assist regional and national intercomparisons of surface/sub-surface instrumentation. Ensure that relevant findings from these intercomparisons are included in updated guidance material.
10. Liaise effectively with the Expert Team on Transition to Modern Measurements on developments of guidelines and training material for supporting activities relevant to the ET Terms of Reference.