1. WMO Climate-relevant operational Metadata Peer Hechler, Omar Baddour WMO; WIS DMA

2. WMO Metadata requirements for climate (1/5)  Principles from a climate perspective: (i) Metadata should be managed in a way that allows for reflecting and retrieving all changes in the history of the observation/ instrument/ station/ network, such as siting, instrumentation, times of observations etc., but also establishment of station, commencement of observations, interruptions of operation, closure of station including one-to-one ID attribution (no use of same ID for different station through history); (ii) Metadata should allow for re-calculation of processed data.  Metadata should be accessible and exchangeable equally conveniently as the meteorological/climatological data itself  The below listed metadata requirements are subject to further discussion and might be prioritised (required, optional). Wording to be revised. List not exhaustive.

3. WMO Metadata requirements for climate (2/5)  Station identifier(s) incl. index number and name  Contact information (name, mailing address, Email address, phone numbers)  Station actors (owner, manager, observers incl. their level of experience/qualification etc.)  Station type (fixed land, fixed sea, mobile land etc.)  Location (exact geographical location incl. elevation)  Roughness, topography of station and environment, land use  Photography, site plan and skyline diagram of station and environment  Type(s) of soil incl. physical constants and profile of soil  Type(s) of vegetation  Observation programme (elements measured, reference time, times at which observations and measurements are made and reported, datum level to which atmospheric pressure data of the station refer)  Inspection reports

4. WMO Metadata requirements for climate (3/5)  Instruments (detailed instrument descriptions incl. manufacturer, model, serial number, date of installation )  Instrument and instrument maintenance status (active, out of service, under repair; maint. frequency, calibration results etc.)  Siting and exposure of instrument incl. photos  Description of parameters measured by the instrument incl. unit, range, resolution, format, frequency, accuracy, method, algorithm, time constant, output averaging time etc.  Principle of operation, method of measurement and observation, type of detection system, performance characteristics  Data acquisition incl. sampling interval, averaging interval  Correction procedures and calibration information  Type of AWS incl. manufacturer, model, serial number

5. WMO Metadata requirements for climate (4/5)  Measuring/observing programme of elements (times of observation, reporting frequency, data output  Data processing method and intervalls  Procedures, algorithms, calculation methods, constants, reported resolution  Data handling: Quality Control procedures and algorithms incl. corrections by the observer  Definition of QC-flags  Storage procedures  Method of transmission, data format, transmission time and frequency  ? Station network Metadata, such as mission, operator, principles…??