morphing_epw() takes an epw_cmip6_data object generated using extract_data() and calculates future core EPW weather variables using Morphing Method.

morphing_epw(data, years = NULL, labels = NULL, methods = NULL)



An epw_cmip6_dataobject generated using extract_data()


An integer vector indicating the target years to be considered. If NULL, all years in input data will be considered. Default: NULL.


A character or factor vector used for grouping input years. Usually are the outputs of base::cut(). labels should have the same length as years. If given, climate data of years grouped by labels will be averaged. Default: NULL.


A named character giving the methods of morphing procedures of each variables. Possible variable names are tdb, rh, p, hor_ir, glob_rad, wind. Possible values are: "stretch", "shift" and "combined". For example: c(tdb = "stretch", rh = "shift"). "combined" is only applicable to tdb. The default morphing method for each variable is listed in the Return section. If NULL, the default methods will be used. Default: NULL.


An epw_cmip6_morphed object, which is basically a list of 12 elements:

No.ElementTypeMorphing MethodDescription
1epweplusr::EpwN/AThe original EPW file used for morphing
2tdbdata.table::data.table()StretchData of dry-bulb temperature after morphing
3tdewdata.table::data.table()DerivedData of dew-point temperature after morphing
4rhdata.table::data.table()StretchData of relative humidity after morphing
5pdata.table::data.table()StretchData of atmospheric pressure after morphing
6hor_irdata.table::data.table()StretchData of horizontal infrared radiation from the sky after morphing
7glob_raddata.table::data.table()StretchData of global horizontal radiation after morphing
8norm_raddata.table::data.table()DerivedData of direct normal radiation after morphing
9diff_raddata.table::data.table()StretchData of diffuse horizontal radiation after morphing
10winddata.table::data.table()StretchData of wind speed after morphing
11total_coverdata.table::data.table()DerivedData of total sky cover after morphing
12opaque_coverdata.table::data.table()DerivedData of opaque sky cover after morphing

Each data.table::data.table() listed above contains x columns

1activity_drsCharacterActivity DRS (Data Reference Syntax)
2institution_idCharacterInstitution identifier
3source_idCharacterModel identifier
4experiment_idCharacterRoot experiment identifier
5member_idCharacterA compound construction from sub_experiment_id and variant_label
6table_idCharacterTable identifier
7latDoubleThe averaged values of input latitude
8lonDoubleThe averaged values of input longitude
9intervalFactorThe year value of data morphed
10Variable NameDoubleThe morphed data, where Variable Name is the corresponding EPW weather variable name
11deltaDoubleThe shift factor. Will be NA for derivied values
12alphaDoubleThe stretch factor. Will be NA for derivied values


The EPW weather variables that get morphed are listed in details.


Belcher, S., Hacker, J., Powell, D., 2005. Constructing design weather data for future climates. Building Services Engineering Research and Technology 26, 49–61.