The Meteorological Service of Canada (MSC) is in the process of modernizing the National Climate and Water Archive (NAS). The goal is to create a paperless archive so that all the operational atmospheric and water quantity monitoring data will be captured and quality controlled in near real-time and will be made available to users in a timely fashion. The current MSC NAS contains long-term operational climate, weather, water, marine, lightning and some air quality monitoring data in both electronic digital format and paper format.

Metadata will play an important role in the modernization of NAS. Metadata is data about data. It describes the content, quality, condition, and other characteristics of data. With proper metadata, users can understand and use the data properly.

The NAS adopts a hierarchical approach to the creation and management of metadata employing the Dublin Core standards and the Content Standards for Digital Geospatial Metadata (CSDGM), which will provide three levels for users to search by. These three levels include Data Discovery, Data Access and Data Exchange. The Data Discovery level provides users with a very high level description of the NAS and information holdings (e.g., providing a description of a data collection). The Data Access level is a mid-level description of the NAS or information holdings that provides more detailed access to data holdings (e.g., where to get the data). The Data Exchange level provides detailed information of the data (e.g., the type of monitoring instrument used). Using these three levels will allow a user to search for more detailed information only when required and not be inundated by numerous returns of information if not needed, which will allow for more efficient and quicker searches. In addition, to ensure consistency in both the cataloguing or indexing and searching of Environment Canada metadata repositories, controlled vocabularies (such as keywords) from standardized thesauri will be used during subject searches.

In addition, NAS contains a detailed operational database on monitoring station information (station location, opening and closing dates, instrumentations and instrumentation changing dates, maintenance schedule, operational schedule, observing program, station owner, etc.). A lot of information contained in the station information database is required by the metadata system. We are in the process of interfacing the operational station information system with the standardized metadata to improve efficiency of development the metadata database.