Saturday, March 27, 2010

More Holes than a Swiss Cheese

It seems that looking at the effective data start date is not the only yardstick by which to evaluate the BoM "high quality" RCS stations. It is also necessary to graph the data to look for the additional holes in the data.

In the previous post, we noticed that several stations had data missing for 40 or more years beyond their notional commencement date. One of the stations looked at was 008039-Dalwallinu, which has a notional start date of 1912, but a data start date of 1955 - or 43 years of missing data. Upon closer examination it appears that the continuous data start date is actually 1957. A closer look again shows that there is missing data for 1970 as well, which clearly shows on the graph of the data:

There are several stations that have incomplete data in the early years, including:
As bad as they are, the sample above are by no means the worst of the bunch. Several of the stations have large gaps in the middle of the data as well, including:

014508 - Gove Airport - [data] [graph]

017043 - Oodnadatta Airport - [data] [graph]

063005 - Bathurst Agricultural Station - [data] [graph]

200790 - Christmas Island Airport - [data] [graph]

... and even 300000 - Davis Station - [data] [graph]

As noted in the previous post, there are 32 RCS stations that have data missing from the beginning of the dataset. From this analysis, we see that there are 22 RCS stations that have data missing beyond the initial start date. Eight of these RCS stations are in the same list as the previous post, which means that there is a total of 46 RCS stations (or a staggering 44.6%) that have significant missing data.

In the HARRY_READ_ME.txt file from the CRU ("Climategate") files, the author of the READ_ME makes the following telling comments:

"getting seriously fed up with the state of the Australian data. so many new stations have been introduced, so many false references.. so many changes that aren't documented."
"Now looking at the dates.. something bad has happened, hasn't it. COBAR AIRPORT AWS cannot start in 1962, it didn't open until 1993!"
"I am very sorry to report that the rest of the databases seem to be in nearly as poor a state as Australia was."
It is very hard to disagree with these comments. In this and the last two posts it has become apparent that:
  • Cunderdin station has been summarily dropped out of the RCS network and substituted by Cunderdin Airport (with no documentation to indicate the change).
  • Many stations exhibit the same problems as "Harry" observed with Cobar Airport
  • Over 44% of the stations have sigificant amounts of data missing - in a number of cases, enough to make the data that is left unusable.
One does not have to be a rocket scientist to appreciate the frustration that "Harry" must have gone through in attempting to make sense of the RCS data. How bad is the RCS data? It's all hidden in plain view for anyone who takes the time to look.

1 comment:

  1. Hello,

    This is good work - keep at it.