Re: CRU data accessibility.
National Meteorological Services (NMSs) have different rules on data exchange. The World Meteorological Organization (WMO) organizes the exchange of “basic data”, i.e. data that are needed for weather forecasts. For details on these see WMO resolution number 40 (see http://bit.ly/8jOjX1).
This document acknowledges that WMO member states can place restrictions on the dissemination of data to third parties “for reasons such as national laws or costs of production”. These restrictions are only supposed to apply to commercial use, the research and education community is supposed to have free access to all the data.
Now, for researchers this sounds open and fine. In practice it hasn’t proved to be so.
Most NMSs also can distribute all sorts of data that are classified as “additional data and products”. Restrictions can be placed on these. These special data and products (which can range from regular weather data from a specific station to maps of rain intensity based on satellite and radar data). Many nations do place restrictions on such data (see link for additional data on above WMO-40 webpage for details).
The reasons for restricting access is often commercial, NMSs are often required by law to have substantial income from commercial sources, in other cases it can be for national security reasons, but in many cases (in my experience) the reasons simply seem to be “because we can”.
What has this got to do with CRU? The data that CRU needs for their data base comes from entities that restrict access to much of their data. And even better, since the UK has submitted an exception for additional data, some nations that otherwise would provide data without question will not provide data to the UK. I know this from experience, since my nation (Iceland) did send in such conditions and for years I had problem getting certain data from the US.
The ideal, that all data should be free and open is unfortunately not adhered to by a large portion of the meteorological community. Probably only a small portion of the CRU data is “locked” but the end effect is that all their data becomes closed. It is not their fault, and I am sure that they dislike them as much as any other researcher who has tried to get access to all data from stations in region X in country Y.
These restrictions end up by wasting resources and hurting everyone. The research community (CRU included) and the public are the victims. If you don’t like it, write to you NMSs and urge them to open all their data.
I can update (further) this if there is demand. Please let me know in the comments, which, as always, should be substantive, non-insulting and on topic.