Thursday, October 9, 2014

Portal for GHCN Daily

Many people are aware of GHCN Monthly. This is the large compilation of station monthly averages used for making global indices. I posted a portal here. Fewer know about GHCN daily, which is a very large compilation of daily records. Partly because of its size, it is less accessible. Each station record is in a separate file, and even listing the "all" directory takes a long time.

It is far less organized than GHCN Monthly. Many records are very short and incomplete. There is a mixture of TMAX, TMIN, precipitation, and various things like snow. Not easy. It is, however, for those who like that sort of thing, unadjusted. Very raw data.

So I've organised some links. I've split into US1, USC, Australia, Canada and others. US1 seems to have little or no temp data. USC is basically the Co-op network. The Australia record is huge, but a lot is rainfall. Canada is also large. So I've broken down those by states, and other countries are in the "World" list. Even there, some very significant countries are in the "Other" group at the end. Coverage is very uneven.

I've marked the files that have temp data (well, TMAX) with the years of record. As I mentioned, these can be short, and full of gaps at that. Entries without years probably don't have temperature. On the "Other" list, I've also marked where each country block begins.

So it's below the jump. You request by selecting from one of the menus. Clicking on a link will make the actual record pop up in a separate window or tab. I'm planning to create a permanent page for the various portals.

Update: I've added buttons that with Chrome will force the selection to take effect.



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