Output metadata#

Output metadata contains at least the following variables:

lat
lat_bnds
lon_bnds
lon
time
time_bnds
index

lat, lon, lat_bnds, lon_bnds#

They are copied from source file with all their attributes.

time and time_bnds#

Slice_mode	time	time_bnds
`year`	YYYY-07-01	YYYY-01-01	(YYYY+1)-01-01
`month`	YYYY-MM-16	YYYY-MM-01	YYYY-(MM+1)-01
`ONDJFM`	YYYY-01-01	YYYY-10-01	(YYYY+1)-04-01
`AMJJAS`	YYYY-07-01	YYYY-04-01	YYYY-10-01
`DJF`	YYYY-01-16	YYYY-12-01	(YYYY+1)-03-01
`MAM`	YYYY-04-16	YYYY-03-01	YYYY-06-01
`JJA`	YYYY-07-16	YYYY-06-01	YYYY-09-01
`SON`	YYYY-10-16	YYYY-09-01	YYYY-12-01

Note

The second bound in time_bnds is excluded!

Example: annual time steps#

$ ncdump -v time indice_FD_year_1950-1955.nc -t

time = "1950-07-01", "1951-07-01", "1952-07-01", "1953-07-01",
    "1954-07-01", "1955-07-01" ;

$ ncdump -v time_bnds indice_FD_year_1950-1955.nc -t

time_bnds =
    "1950-01-01 12", "1951-01-01 12",
    "1951-01-01 12", "1952-01-01 12",
    "1952-01-01 12", "1953-01-01 12",
    "1953-01-01 12", "1954-01-01 12",
    "1954-01-01 12", "1955-01-01 12",
    "1955-01-01 12", "1956-01-01 12" ;

Example: monthly time steps#

$ ncdump -v time indice_FD_month_1950-1955.nc -t

time = "1950-01-16", "1950-02-16", "1950-03-16", "1950-04-16",
    "1950-05-16", "1950-06-16", "1950-07-16", "1950-08-16",
    "1950-05-16", "1950-06-16", "1950-07-16", "1950-08-16",
    [...]

$ ncdump -v time_bnds indice_FD_month_1950-1955.nc -t

time_bnds =
    "1950-01-01 12", "1950-02-01 12",
    "1950-02-01 12", "1950-03-01 12",
    "1950-03-01 12", "1950-04-01 12",
    "1950-04-01 12", "1950-05-01 12",
    [...]

Example: seasonal time steps#

$ ncdump -v time indice_FD_DJF_1950-1955.nc -t

time = "1951-01-16", "1952-01-16", "1953-01-16", "1954-01-16",
    "1955-01-16" ;

$ ncdump -v time_bnds indice_FD_DJF_1950-1955.nc -t

time_bnds =
    "1950-12-01 12", "1951-03-01 12",
    "1951-12-01 12", "1952-03-01 12",
    "1952-12-01 12", "1953-03-01 12",
    "1953-12-01 12", "1954-03-01 12",
    "1954-12-01 12", "1955-03-01 12" ;

$ ncdump -v time indice_FD_SON_1950-1955.nc -t

time = "1950-10-16", "1951-10-16", "1952-10-16", "1953-10-16",
    "1954-10-16", "1955-10-16" ;

$ ncdump -v time_bnds indice_FD_SON_1950-1955.nc -t

time_bnds =
    "1950-09-01 12", "1950-12-01 12",
    "1951-09-01 12", "1951-12-01 12",
    "1952-09-01 12", "1952-12-01 12",
    "1953-09-01 12", "1953-12-01 12",
    "1954-09-01 12", "1954-12-01 12",
    "1955-09-01 12", "1955-12-01 12" ;

index#

The index variable has the same name as index_name parameter (e.g. “FD”). It has the following attributes:

long_name

units

_FillValue

missing_value

( grid_mapping )

Example:

float FD(time, lat, lon) ;
        FD:_FillValue = 1.e+20f ;
        FD:long_name = "Frost days (minimum temperature < 0 degrees)" ;
        FD:units = "days" ;
        FD:missing_value = 1.e+20f ;
        FD:standard_name = "ECA_index" ;

Note

The _FillValue and missing_value are the same as in source files.

Global attributes#

According to the CF convention, the output NetCDF file contains 6 main global attributes:

title
institution
source
history
references
comment

Example:

// global attributes:
    :title = "ECA cold index FD" ;
    :institution = "Climate impact portal (https://climate4impact.eu)" ;
    :source =  ;
    :references = "ATBD of the ECA indices calculation (https://knmi-ecad-assets-prd.s3.amazonaws.com/documents/atbd.pdf)" ;
    :comment = " " ;
    :history = "2011-04-07T06:39:36Z CMOR rewrote data to comply with CF standards and CMIP5 requirements. \n",
                    "2014-04-01 12:16:03 Calculation of FD index (monthly time series) from 1950-1-1 to 1955-12-31." ;