Basic demo¶

This notebook gives a basic demonstration of how to use OpenSCM-Units.

For further details, see the rest of the notebooks.

In [1]:

import numpy as np

import openscm_units

import numpy as np import openscm_units

In [2]:

UR = openscm_units.unit_registry

UR = openscm_units.unit_registry

In [3]:

print(f"You are using openscm_units version {openscm_units.__version__}")

print(f"You are using openscm_units version {openscm_units.__version__}")

You are using openscm_units version 0.6.3

Usage¶

With OpenSCM-Units it is possible to attach units to quantities. This is all based on the the Pint library. For full details, see Pint's docs.

OpenSCM-Units adds a number of units relevant to simple climate modelling to Pint's standard registry.

Emissions¶

For example, we can define quantities with emissions units.

In [4]:

emissions_aus = UR.Quantity(np.array([350, 355, 358]), "Mt CO2 / yr")
emissions_aus

emissions_aus = UR.Quantity(np.array([350, 355, 358]), "Mt CO2 / yr") emissions_aus

Out[4]:

Magnitude	[350 355 358]
Units	CO2 megametric_ton/yr

We can then trivially convert these units to other, equivalent, units.

In [5]:

emissions_aus.to("GtC / yr")

emissions_aus.to("GtC / yr")

Out[5]:

Magnitude	[0.09545454545454547 0.09681818181818184 0.09763636363636366]
Units	gigatC/yr

Concentrations¶

We can also define quantities with concentrations units.

In [6]:

annual_co2_increase = UR.Quantity(2.2, "ppm / yr")
annual_co2_increase

annual_co2_increase = UR.Quantity(2.2, "ppm / yr") annual_co2_increase

Out[6]:

2.2 ppm/yr

We can then trivially convert these units to other, equivalent, units.

In [7]:

annual_co2_increase.to("ppb / yr")

annual_co2_increase.to("ppb / yr")

Out[7]:

2200.0 ppb/yr

Operations¶

Thanks to Pint, units are then carried through operations.

In [8]:

annual_co2_increase_erf_equiv = (
    UR.Quantity(4.0, "W / m^2")
    / np.log(2)
    / UR.Quantity(1, "yr")
    * np.log(1 + annual_co2_increase * UR.Quantity(1, "yr") / UR.Quantity(278, "ppm"))
)
annual_co2_increase_erf_equiv

annual_co2_increase_erf_equiv = ( UR.Quantity(4.0, "W / m^2") / np.log(2) / UR.Quantity(1, "yr") * np.log(1 + annual_co2_increase * UR.Quantity(1, "yr") / UR.Quantity(278, "ppm")) ) annual_co2_increase_erf_equiv

Out[8]:

0.045488291279792724 watt/(meter² yr)

Further details¶

This provides a very brief overview to the basic principles. For further details, see design principles and Pint's docs. The notebook on design principles is a good starting point.