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User indices recipes#

Note

User indices are deprecated. You should switch to Generic indices recipes API.

import icclim
import datetime

Max of tas within the year#

from icclim.util import callback

my_index_params = {"index_name": "my_index", "calc_operation": "max"}

file_tas = "tas_day_CNRM-CM5_historical_r1i1p1_19010101-20001231.nc"
out_f = "my_index.nc"

icclim.index(
    user_index=my_index_params,
    in_files=file_tas,
    var_name="tas",
    slice_mode="year",
    out_file=out_f,
    callback=callback.defaultCallback2,
)

Min of positive values within the year and the date of this minimum#

Get minimum temperature which is above zero Celsius and find its date.

Warning

If input data are in Kelvin, then thresh must be in Kelvin too.

Note

An additional variable will be created in output netCDF file: “date_event” with the date of the first occurrence of min positive.

my_index_params = {
    "index_name": "my_index",
    "calc_operation": "min",
    "logical_operation": "gt",
    "thresh": 0 + 273.15,  ### input data in Kelvin ==> threshold in Kelvin!
    "date_event": True,
}

file_tasmin = "tasmin_day_CNRM-CM5_historical_r1i1p1_19010101-20001231.nc"
out_f = "my_index.nc"

icclim.index(
    user_index=my_index_params,
    in_files=file_tasmin,
    var_name="tasmin",
    slice_mode="year",
    out_file=out_f,
    callback=callback.defaultCallback2,
)

Mean of a selected period#

Note

slice_mode must be None to apply the operation to the whole period of selected time range.

my_index_params = {"index_name": "my_index", "calc_operation": "mean"}

file_tas = "tas_day_CNRM-CM5_historical_r1i1p1_19010101-20001231.nc"
out_f = "my_index.nc"

tr = [datetime.datetime(1901, 1, 1), datetime.datetime(1920, 12, 31)]

icclim.index(
    user_index=my_index_params,
    in_files=file_tas,
    var_name="tas",
    slice_mode=None,
    time_range=tr,
    out_file=out_f,
    callback=callback.defaultCallback2,
)

Number of days when tas < 15 degrees Celsius of each Autumn#

Note

If ‘calc_operation’ is ‘max_nb_consecutive_events’, then max number of consecutive days for the same condition will be computed.

my_index_params = {
    "index_name": "my_index",
    "calc_operation": "nb_events",  ### 'calc_operation': 'max_nb_consecutive_events'
    "logical_operation": "lt",
    "thresh": 15 + 273.15,  ### input data in Kelvin ==> threshold in Kelvin!
}

file_tas = "tas_day_CNRM-CM5_historical_r1i1p1_19010101-20001231.nc"
out_f = "my_index.nc"

icclim.index(
    user_index=my_index_params,
    in_files=file_tas,
    var_name="tas",
    slice_mode="SON",
    out_unit="days",
    out_file=out_f,
    callback=callback.defaultCallback2,
)

Percentage of days when tasmax > 80th pctl and at which date it happens#

Note

If ‘calc_operation’ is ‘max_nb_consecutive_events’, then max number of consecutive days for the same condition will be computed.

Note

80th pctl: 80th percentile of tasmax in base period

Note

Two additional variables will be created in output netCDF file: “date_event_start” (the date of the first occurence of tasmax > 80th pctl) and “date_event_end” (the date of the last occurence of tasmax > 80th pctl).

my_index_params = {
    "index_name": "my_index",
    "calc_operation": "nb_events",
    "logical_operation": "gt",
    "thresh": "p80",
    "var_type": "t",
    "date_event": True,
}

file_tasmax = "tasmax_day_CNRM-CM5_historical_r1i1p1_19010101-20001231.nc"
out_f = "my_index.nc"
bp = [datetime.datetime(1960, 1, 1), datetime.datetime(1969, 12, 31)]

icclim.index(
    user_index=my_index_params,
    in_files=file_tasmax,
    var_name="tasmax",
    slice_mode="year",
    base_period_time_range=bp,
    out_unit="%",
    out_file=out_f,
    callback=callback.defaultCallback2,
)

Number of days when daily precipitation amount > 85th pctl#

Note

If ‘calc_operation’ is ‘max_nb_consecutive_events’, then max number of consecutive days for the same condition will be computed.

Note

daily precipitation amount: daily precipitation amount on a wet day (RR >= 1.0 mm)

Note

85th pctl: percentile of precipitation on wet days in base period

my_index_params = {
    "index_name": "my_index",
    "calc_operation": "nb_events",  ### 'calc_operation': 'max_nb_consecutive_events'
    "logical_operation": "gt",
    "thresh": "p85",
    "var_type": "p",
}

file_pr = "pr_day_CNRM-CM5_historical_r1i1p1_19010101-20001231.nc"
out_f = "my_index.nc"

icclim.index(
    user_index=my_index_params,
    in_files=file_pr,
    var_name="pr",
    slice_mode="year",
    base_period_time_range=bp,
    out_unit="days",
    out_file=out_f,
    callback=callback.defaultCallback2,
)

Max number of consecutive days when tasmax >= 25 degrees Celsius + date of the events#

Note

Two additional variables will be created in output netCDF file: “date_event_start” (the first date of the found sequence) and “date_event_end” (the last date of the found sequence).

Warning

If there are several sequences of the same length, the “date_event_start” and “date_event_end” will correspond to the first sequence.

my_index_params = {
    "index_name": "my_index",
    "calc_operation": "max_nb_consecutive_events",
    "logical_operation": "get",
    "thresh": 25 + 273.15,  ### input data in Kelvin ==> threshold in Kelvin!
    "date_event": True,
}

file_tasmax = "tasmax_day_CNRM-CM5_historical_r1i1p1_19010101-20001231.nc"
out_f = "my_index.nc"

icclim.index(
    user_index=my_index_params,
    in_files=file_tasmax,
    var_name="tasmax",
    slice_mode="year",
    out_file=out_f,
    callback=callback.defaultCallback2,
)

Max of sum of precipitation in 10 consecutive days#

my_index_params = {
    "index_name": "my_index",
    "calc_operation": "run_sum",
    "extreme_mode": "max",
    "window_width": 10,
}

file_pr = "pr_day_CNRM-CM5_historical_r1i1p1_19010101-20001231.nc"
out_f = "my_index.nc"

icclim.index(
    user_index=my_index_params,
    in_files=file_pr,
    var_name="pr",
    slice_mode=["season", [4, 5, 6, 7, 8]],
    out_file=out_f,
    callback=callback.defaultCallback2,
)

Min of mean of tasmin in 7 consecutive days + date of the events#

Note

Two additional variables will be created in output netCDF file: “date_event_start” (the date corrsponding to the beggining of the “window” satisfying the condition) and “date_event_end” (the date corrsponding to the end of the “window” satisfying the condition).

Warning

If several “windows” with the same result are found, the “date_event_start” and “date_event_end” will correspond to the first one.

my_index_params = {
    "index_name": "my_index",
    "calc_operation": "run_mean",
    "extreme_mode": "min",
    "window_width": 7,
    "date_event": True,
}

file_tasmin = "tasmin_day_CNRM-CM5_historical_r1i1p1_19010101-20001231.nc"
out_f = "my_index.nc"

icclim.index(
    user_index=my_index_params,
    in_files=file_tasmin,
    var_name="tasmin",
    slice_mode=["season", ([11, 12], [1, 2])],
    out_file=out_f,
    callback=callback.defaultCallback2,
)

Anomaly of tasmax between 2 period of 30 years#

Note

Result could be returned as percentage value relative to mean value of reference period, if out_unit='%'.

my_index_params = {"index_name": "my_index", "calc_operation": "anomaly"}

file_tasmax = "tasmax_day_CNRM-CM5_historical_r1i1p1_19010101-20001231.nc"
out_f = "my_index.nc"
# studied period: future period
tr = [datetime.datetime(1971, 1, 1), datetime.datetime(2000, 12, 31)]
# reference period: past period
tr_base = [datetime.datetime(1901, 1, 1), datetime.datetime(1930, 12, 31)]

icclim.index(
    user_index=my_index_params,
    in_files=file_tasmax,
    var_name="tasmax",
    time_range=tr,
    base_period_time_range=tr_base,
    out_file=out_f,
    callback=callback.defaultCallback2,
)

Number of days when tasmin >= 10 degrees Celsius and tasmax > 25 degrees Celsius#

Note

If ‘calc_operation’ is ‘max_nb_consecutive_events’, then max number of consecutive days for the same condition will be computed.

my_index_params = {
    "index_name": "my_index",
    "calc_operation": "nb_events",  ### 'calc_operation': 'max_nb_consecutive_events'
    "logical_operation": ["get", "gt"],
    "thresh": [
        10 + 273.15,
        25 + 273.15,
    ],  ### input data in Kelvin ==> threshold in Kelvin!
    "link_logical_operations": "and",
}

file_tasmin = "tasmin_day_CNRM-CM5_historical_r1i1p1_19010101-20001231.nc"
file_tasmax = "tasmax_day_CNRM-CM5_historical_r1i1p1_19010101-20001231.nc"
out_f = "my_index.nc"

icclim.index(
    user_index=my_index_params,
    in_files=[file_tasmin, file_tasmax],
    var_name=["tasmin", "tasmax"],
    slice_mode="JJA",
    out_unit="days",
    out_file=out_f,
    callback=callback.defaultCallback2,
)

Percentage of days when tasmin >= 10 degrees Celsius and tasmax > 90th pctl + date of the events#

Note

If ‘calc_operation’ is ‘max_nb_consecutive_events’, then max number of consecutive days for the same condition will be computed.

Note

It is possible to use numeric and percentile threshold at the time.

my_index_params = {
    "index_name": "my_index",
    "calc_operation": "nb_events",  ### 'calc_operation': 'max_nb_consecutive_events'
    "logical_operation": ["get", "gt"],
    "thresh": [
        10 + 273.15,
        "p90",
    ],  ### input data in Kelvin ==> threshold in Kelvin!
    "var_type": "t",  ### or ['-','t']
    "link_logical_operations": "and",
    "date_event": True,
}

file_tasmin = "tasmin_day_CNRM-CM5_historical_r1i1p1_19010101-20001231.nc"
file_tasmax = "tasmax_day_CNRM-CM5_historical_r1i1p1_19010101-20001231.nc"
out_f = "my_index.nc"

bp = [datetime.datetime(1960, 1, 1), datetime.datetime(1969, 12, 31)]
icclim.index(
    user_index=my_index_params,
    in_files=[file_tasmin, file_tasmax],
    var_name=["tasmin", "tasmax"],
    slice_mode="JJA",
    base_period_time_range=bp,
    out_unit="%",
    out_file=out_f,
    callback=callback.defaultCallback2,
)

Number of days when tas < 25th pctl and precip. > 75th pctl#

Note

If ‘calc_operation’ is ‘max_nb_consecutive_events’, then max number of consecutive days for the same condition will be computed.

4 compound indices defined in https://knmi-ecad-assets-prd.s3.amazonaws.com/documents/atbd.pdf (see the section 5.3.3 “Compound indices”) are based on daily precipitation (RR) and mean temperature (TG) variables:

  • CD (cold/dry days): (TG < 25th pctl) and (RR < 25th pctl)

  • CW (cold/wet days): (TG < 25th pctl) and (RR > 75th pctl)

  • WD (warm/dry days): (TG > 75th pctl) and (RR < 25th pctl)

  • WW (warm/wet days): (TG > 75th pctl) and (RR > 75th pctl)

Note

RR is a daily precipitation on a wet day, and its percentile value is computed from set of wet days also.

Note

Percentiles thresholds computing uses differents methods as it was described here.

my_index_params = {
    "index_name": "my_index",
    "calc_operation": "nb_events",  ### 'calc_operation': 'max_nb_consecutive_events'
    "logical_operation": ["lt", "gt"],
    "thresh": ["p25", "p75"],
    "var_type": ["t", "p"],
    "link_logical_operations": "and",
}

file_pr = "pr_day_CNRM-CM5_historical_r1i1p1_19010101-20001231.nc"
file_tas = "tas_day_CNRM-CM5_historical_r1i1p1_19010101-20001231.nc"
out_f = "my_index.nc"

bp = [datetime.datetime(1960, 1, 1), datetime.datetime(1969, 12, 31)]
icclim.index(
    user_index=my_index_params,
    in_files=[file_tas, file_pr],
    var_name=["tas", "pr"],
    slice_mode="year",
    out_unit="days",
    base_period_time_range=bp,
    out_file=out_f,
    callback=callback.defaultCallback2,
)

Number of days when tasmax > 90th pctl and tasmin >= 10 and precipitation < 30th pctl#

Note

If ‘calc_operation’ is ‘max_nb_consecutive_events’, then max number of consecutive days for the same condition will be computed.

my_index_params = {
    "index_name": "my_index",
    "calc_operation": "nb_events",  ### 'calc_operation': 'max_nb_consecutive_events'
    "logical_operation": ["gt", "get", "lt"],
    "thresh": ["p90", 10 + 273.15, "p30"],
    "var_type": ["t", "-", "p"],
    "link_logical_operations": "and",
}
file_pr = "pr_day_CNRM-CM5_historical_r1i1p1_19010101-20001231.nc"
file_tasmax = "tasmax_day_CNRM-CM5_historical_r1i1p1_19010101-20001231.nc"
file_tasmin = "tasmin_day_CNRM-CM5_historical_r1i1p1_19010101-20001231.nc"
out_f = "my_index.nc"

bp = [datetime.datetime(1960, 1, 1), datetime.datetime(1969, 12, 31)]
icclim.index(
    user_index=my_index_params,
    in_files=[file_tasmax, file_tasmin, file_pr],
    var_name=["tasmax", "tasmin", "pr"],
    slice_mode="SON",
    out_unit="days",
    base_period_time_range=bp,
    out_file=out_f,
    callback=callback.defaultCallback2,
)
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