Create a lower-resolution time series

This function creates a lower (or equal) resolution time series from
the one displayed above.
The options are quite general, and allow for
the computation of most standard derived time series.
You can transform into any of the time resolutions the Climate Explorer understands: annual, seasonal (DJF, MAM, JJA, SON), monthly, decadal (1-10, 11-20, 21-end), pentad, or daily (6-hourly is experimental). The pentad including February 29 in a leap year is over 6 days.

You can take the mean, standard deviation, min and max of the time series when going to a lower time resolution. The options sum above, sum below and number are used in combination with a threshold. This allows the construction of heating degree days (sum above 17°C), warm days (number of days with temperature above the 95th percentile), number of days with dense fog (number below 201m), etc. The threshold can be specified in the absolute units of the time series, as percentile, or relative to the 1971-2000 normals.

Note that the Climate Explorer cannot correlate two datasets with a different time resolution, you should always use this function (or its converse) to convert one of the two to the time scale of the other.