Station metadata are an essential part of climate information. Accurate metadata is are paramount for data users in understanding observational data and artificial discontinuities that invariably occur as a result of events beyond our control. Simply stated, metadata are "data about data."

Metadata provides the critical a historical record of how and where the data are collected over time. This includes such topics as the setup (exposure) of instruments, types of, and changes to instrumentation, changes in observing practices (time of observation, use of snow measurement boards), changes in the environmental site characteristics, dates of maintenance visits, changes in algorithms for processing and measuring the environment, and type of work performed, etc.

Metadata helps us understand and account for unwanted artificial discontinuities in the climate record.
What information should documented? Any factors that affects the data and/or the way we interpret the climate record. These include:

1) changes in the way measurements are made and recorded, and,
2) changes in the local physical environment.

Remember: Err on the side of over-documentation. There is no penalty for doing so, and once formed as a habit, it takes relatively little extra time to complete.

Recommended Metadata-Related Action:

The following actions are recommended to minimize unwanted discontinuities in the climate record:

1) Understand and honor the principle that metadata are as important a part of the data as the observations themselves. Keep a complete metadata record for each published climate station in compliance with Cooperative Station Service Accountability (CSSA) guidance and the "Ten Principles of Climate Monitoring (PCU6-1)."

2) Document any changes (sudden or slow) in site circumstances that can bias instrument measurements. Pay special attention to changes in the environment of the site such a forest cutting, changes in irrigation/fallow status of nearby crops, turf watering practices at the site, expansion or changes from gravel of asphalt driveways, roads and parking lots, encroachment of vegetation, new obstructions that affect wind flow, replaced or new sensors, changes in color or dirtiness of white shelter housing, vertical walls that provide additional infrared radiation at night, etc. Insure that the station's metadata archive include digital photographs of the site for the eight points of the compass, updated annually with scheduled preventative maintenance visits.

3) Insure that observing changes and the date of occurrence, such as the implementation of new snow measurement boards, changing observation times, moved equipment, replaced or new instrumentation, changes in the environment within 200 feet of the station, different processing algorithms, etc. are recorded in the metadata.

4) Coordinate with your RCSPM and other climate services partners (NCDC, RCCs, SCs) on any related issues.