src/metpy/constants/__init__.py
# Copyright (c) 2008,2015,2016,2018,2021 MetPy Developers.
# Distributed under the terms of the BSD 3-Clause License.
# SPDX-License-Identifier: BSD-3-Clause
r"""A collection of meteorologically significant constant and thermophysical property values.
Earth
-----
======================== =============== =========== ======================================= ===============================================================
Name Symbol Short Name Units Description
------------------------ --------------- ----------- --------------------------------------- ---------------------------------------------------------------
earth_avg_radius :math:`R_e` Re :math:`\text{m}` Avg. radius of the Earth [1]_
earth_gravity :math:`g` g :math:`\text{m s}^{-2}` Avg. gravity acceleration on Earth [2]_
gravitational_constant :math:`G` G :math:`\text{m}^{3} {kg}^{-1} {s}^{-2}` Gravitational constant [2]_
earth_avg_angular_vel :math:`\Omega` omega :math:`\text{rad s}^{-1}` Avg. angular velocity of Earth [1]_
earth_sfc_avg_dist_sun :math:`d` d :math:`\text{m}` Avg. distance of the Earth from the Sun [3]_
earth_solar_irradiance :math:`S` S :math:`\text{W m}^{-2}` Avg. solar irradiance of Earth [4]_
earth_max_declination :math:`\delta` delta :math:`\text{degrees}` Max. solar declination angle of Earth
earth_orbit_eccentricity :math:`e` :math:`\text{None}` Avg. eccentricity of Earth's orbit
earth_mass :math:`m_e` me :math:`\text{kg}` Total mass of the Earth (approx) [1]_ [2]_
======================== =============== =========== ======================================= ===============================================================
Water
-----
======================= ================ ========== ============================ ====================================================
Name Symbol Short Name Units Description
----------------------- ---------------- ---------- ---------------------------- ----------------------------------------------------
water_molecular_weight :math:`M_w` Mw :math:`\text{g mol}^{-1}` Molecular weight of water [5]_
water_gas_constant :math:`R_v` Rv :math:`\text{J (K kg)}^{-1}` Gas constant for water vapor [2]_ [5]_
density_water :math:`\rho_l` rho_l :math:`\text{kg m}^{-3}` Maximum recommended density of liquid water, 0-40C [5]_
wv_specific_heat_press :math:`C_{pv}` Cp_v :math:`\text{J (K kg)}^{-1}` Specific heat at constant pressure for water vapor
wv_specific_heat_vol :math:`C_{vv}` Cv_v :math:`\text{J (K kg)}^{-1}` Specific heat at constant volume for water vapor
water_specific_heat :math:`Cp_l` Cp_l :math:`\text{J (K kg)}^{-1}` Specific heat of liquid water at 0C [6]_
water_heat_vaporization :math:`L_v` Lv :math:`\text{J kg}^{-1}` Latent heat of vaporization for liquid water at 0C [7]_
water_heat_fusion :math:`L_f` Lf :math:`\text{J kg}^{-1}` Latent heat of fusion for liquid water at 0C [7]_
ice_specific_heat :math:`C_{pi}` Cp_i :math:`\text{J (K kg)}^{-1}` Specific heat of ice at 0C [7]_
density_ice :math:`\rho_i` rho_i :math:`\text{kg m}^{-3}` Density of ice at 0C
======================= ================ ========== ============================ ====================================================
Dry Air
-------
======================== ================ ============= ============================ ====================================================================
Name Symbol Short Name Units Description
------------------------ ---------------- ------------- ---------------------------- --------------------------------------------------------------------
dry_air_molecular_weight :math:`M_d` Md :math:`\text{g / mol}` Nominal molecular weight of dry air at the surface of th Earth [8]_
dry_air_gas_constant :math:`R_d` Rd :math:`\text{J (K kg)}^{-1}` Gas constant for dry air at the surface of the Earth
dry_air_spec_heat_press :math:`C_{pd}` Cp_d :math:`\text{J (K kg)}^{-1}` Specific heat at constant pressure for dry air
dry_air_spec_heat_vol :math:`C_{vd}` Cv_d :math:`\text{J (K kg)}^{-1}` Specific heat at constant volume for dry air
dry_air_density_stp :math:`\rho_d` rho_d :math:`\text{kg m}^{-3}` Density of dry air at 0C and 1000mb
======================== ================ ============= ============================ ====================================================================
General Meteorology Constants
-----------------------------
======================== ================= =========== ========================= =======================================================
Name Symbol Short Name Units Description
------------------------ ----------------- ----------- ------------------------- -------------------------------------------------------
pot_temp_ref_press :math:`P_0` P0 :math:`\text{Pa}` Reference pressure for potential temperature
poisson_exponent :math:`\kappa` kappa :math:`\text{None}` Exponent in Poisson's equation (Rd/Cp_d)
dry_adiabatic_lapse_rate :math:`\gamma_d` gamma_d :math:`\text{K km}^{-1}` The dry adiabatic lapse rate
molecular_weight_ratio :math:`\epsilon` epsilon :math:`\text{None}` Ratio of molecular weight of water to that of dry air
======================== ================= =========== ========================= =======================================================
.. [1] [Moritz2000]_
.. [2] [CODATA2018]_
.. [3] [IAU2012]_
.. [4] [Kopp2011]_
.. [5] [IAPWS2001]_
.. [6] [IAPWS1995]_
.. [7] [WMO1966]_
.. [8] [Picard2008]_
""" # noqa: E501
from . import nounit # noqa: F401
from .default import * # noqa: F403
from ..package_tools import set_module
__all__ = default.__all__[:] # pylint: disable=undefined-variable
set_module(globals())