Data are downloaded from the Environment Canada's historical data website and cached locally.
download.met( id, year, month, deltat, type = "xml", destdir = ".", destfile, force = FALSE, quiet = FALSE, debug = getOption("oceDebug") )
A number giving the "Station ID" of the station of interest. If not
A number giving the year of interest. Ignored unless
A number giving the month of interest. Ignored unless
Optional character string indicating the time step of the
desired dataset. This may be
String indicating which type of file to download, either
Optional string indicating the directory in which to store
downloaded files. If not supplied,
Optional string indicating the name of the file. If not supplied, the file name is constructed from the other parameters of the function call, so subsequent calls with the same parameters will yield the same result, thus providing the key to the caching scheme.
Logical value indicating whether to force a download, even if the file already exists locally.
Logical value passed to
an integer specifying whether debugging information is
to be printed during the processing. This is a general parameter that
is used by many
String indicating the full pathname to the downloaded file.
The data are downloaded from
pointed to the Environment Canada website (reference 1)
using queries that had to be devised by reverse-engineering, since the agency
does not provide documentation about how to construct queries. Caution: the
query format changes from time to time, so
download.met() may work one
day, and fail the next.
The constructed query contains Station ID, as provided in the
Note that this seems to be a creation of Environment Canada, alone;
it is distinct from the more standard "Climate ID" and "WMO ID".
To make things more difficult, Environment Canada states that the
Station ID is subject to change over time. (Whether this applies to existing
data is unclear.)
Given these difficulties with Station ID, users are advised to consult
the Environment Canada website (reference 1) before downloading any data,
and to check it from time to time
during the course of a research project, to see if the Station ID has changed.
Another approach would be to use Gavin Simpson's
canadaHCD package (reference 2) to look up Station IDs. This package maintains
a copy of the Environment Canada listing of stations, and its
find_station function provides an easy way to determine Station IDs.
After that, its
hcd_hourly function (and related functions) make
it easy to read data. These data can then be converted to the
met class with
as.met(), although doing so leaves
many important metadata blank.
Environment Canada website for Historical Climate Data http://climate.weather.gc.ca/index_e.html
canadaHCD package on GitHub
The work is done with
Other things related to met data: