Database Reference
In-Depth Information
9
-0128 # air temperature (degrees Celsius x 10)
1 # quality code
-0139 # dew point temperature (degrees Celsius x 10)
1 # quality code
10268 # atmospheric pressure (hectopascals x 10)
1 # quality code
Datafiles are organized by date and weather station. There is a directory for each year
from 1901 to 2001, each containing a gzipped file for each weather station with its read-
ings for that year. For example, here are the first entries for 1990:
%
ls raw/1990 | head
010010-99999-1990.gz
010014-99999-1990.gz
010015-99999-1990.gz
010016-99999-1990.gz
010017-99999-1990.gz
010030-99999-1990.gz
010040-99999-1990.gz
010080-99999-1990.gz
010100-99999-1990.gz
010150-99999-1990.gz
There are tens of thousands of weather stations, so the whole dataset is made up of a large
number of relatively small files. It's generally easier and more efficient to process a smal-
ler number of relatively large files, so the data was preprocessed so that each year's read-
ings were concatenated into a single file. (The means by which this was carried out is de-
scribed in
Appendix C
.
)
