earthkit.meteo.thermo.array.specific_humidity_from_dewpoint
===========================================================

.. py:function:: earthkit.meteo.thermo.array.specific_humidity_from_dewpoint(td, p)

   Compute the specific humidity from dewpoint.

   :param td: Dewpoint (K)
   :type td: :class:`array-like`
   :param p: Pressure (Pa)
   :type p: :class:`array-like`

   :returns: Specific humidity (kg/kg)
   :rtype: :class:`array-like`

   The computation starts with determining the vapour pressure:

   .. math::

       e(q, p) = e_{wsat}(td)

   where:

       * :math:`e` is the vapour pressure (see :func:`vapour_pressure_from_specific_humidity`)
       * :math:`e_{wsat}` is the :func:`saturation_vapour_pressure` over water
       * :math:`q` is the specific humidity

   Then `q` is computed from :math:`e` using :func:`specific_humidity_from_vapour_pressure`.