mheslep said:
For clarity, some of the original raw station data has apparently been lost or destroyed as Evo's link states. The information supposedly derivative of that raw data is what has been made available.
For more clarity --- NO.
The original raw data
still exists and is maintained by the bodies that own it, and allowed the CRU to have use of it in their research. The CRU has merged all the raw data that was available to it into a single combined database, which has always existed and is being used all the time to get the final processed data products like CRUTEM.
The processing that was involved in the merge of raw data to a database is comparatively minor; for example it involves combining any duplicated records for a single station. Comments indicate that some of the original records may have been discarded by the CRU sometime after being merged into the combined database of underlying climate data.
The combined database cannot be released, because it contains all of that proprietary station data subject to binding non-disclosure arrangements, merged with all the data from other more open data providers. There is an ongoing work in progress to have this whole combined underlying record made available, but that requires permission from all the owners of the data that appears in the merged database.
You can think of it as a three step process.
Lots and lots of raw data --> combined database of merged raw data --> CRUTEM
The vast majority of the raw data is available. You get it from the holders of that raw data. I don't know that the CRU itself puts up any of it on its own website; that kind of duplication achieves little. You should get the raw data from the owners and maintainers of the raw data, and about 95% of what has been merged is easily available.
The CRU does not release its combined database of merged raw data. It would be a handy thing to have, not so much for auditing, but for use by scientists in other independent calculations of all kinds of things. However, because there is a small amount of data in that merged database that is subject to non-disclosure, you can't simply put up the database for release.
The final processed CRUTEM product is released, of course, and always has been. Other research groups have replicated the entire process as an independent calculation entirely, and obtained the same result to well within measurement errors. This replication is not an audit; but a normal independent repeat as normally done in science to check someone else's results. Such replication takes nothing at all from the CRU, but gets their own data and uses their own calculations to obtain a final result that can be compared with CRUTEM.
Summary:
- It really is the original raw data that is mostly available, not only the processed result. What is available is sufficient for replication in the normal scientific sense of the word.
- The original raw data still exists. It is all held by the appropriate bodies which made it available to the CRU. Scientific replication means taking nothing from the CRU, but doing an independent collection and processing of data.
- The CRU also has a merged database of underlying climate data, which cannot be released because it includes proprietary information that the CRU does not own.
Cheers -- sylas