Principal sources of archive data

Historical weather data take many forms, and can be found in many different archives. This is not a comprehensive study, but an attempt to identify some high-priority items to work on, so we will consider only a subset of possible sources:

• Only observations of clear UK responsibility. Either from UK territory, or archived in the UK, or of particular interest to a UK team or project.
• Only observations made before about 1960. Data from the satellite era are much more likely to be digitised already, and have different user requirements.
• Only instrumental, in-situ, surface observations. Upper-air and subsurface ocean observations have a different user and expert community, they deserve their own study. The same is true for proxy observations (palaeoclimate) and exotic series such as rocketsondes.
• No autograph traces (barograph, thermograph, pluviograph, …). Digitisation of traces is a very different process in practice, and we have little experience in either doing the digitisation or using the results. So these are low priority for current digitisation projects.

That still leaves plenty of records to be considered, we can further divide them into four main groups:

• UK Station data sources
• Ships’ logs
• Foreign data in UK Archives
• Early and Irregular data