def atmosphere(dp):
return const.cp * dp * const.mb_to_Pa / const.g<EOL>
Returns heat capacity of a unit area of atmosphere, in units J /m**2 / K.

    .. math::

        C_a = \\frac{c_p \\cdot dp \\cdot f_{\\textrm{mb-to-Pa}}}{g}

    where

    ==============================  ==============  ==================================================  ===============================================
    variable                        value           unit                                                description
    ==============================  ==============  ==================================================  ===============================================
    :math:`C_a`                     *output*        :math:`\\textrm{J} / \\textrm{m}^2 / \\textrm{K}`      heat capacity for atmospheric cell
    :math:`c_p`                     :math:`1004.`   :math:`\\textrm{J} / \\textrm{kg} / \\textrm{K}`       specific heat at constant pressure for dry air
    :math:`dp`                      *input*         :math:`\\textrm{mb}`                                 pressure for atmospheric cell
    :math:`f_{\\textrm{mb-to-Pa}}`   :math:`100`     :math:`\\textrm{Pa} / \\textrm{mb}`                   conversion factor from mb to Pa
    :math:`g`                       :math:`9.8`     :math:`\\textrm{m} / \\textrm{s}^2`                   gravitational acceleration
    ==============================  ==============  ==================================================  ===============================================

    **Function-call argument** \n

    :param array dp:    pressure intervals (*unit:* mb)
    :returns:           the heat capacity for atmosphere cells correspoding to
                        pressure input (*unit:* J /m**2 / K)
    :rtype:             array

    :Example:

        Calculate atmospheric heat capacity for pressure intervals of
        1, 10, 100 mb::

            >>> from climlab.utils import heat_capacity

            >>> pressure_interval = array([1,10,100]) # in mb
            >>> heat_capacity.atmosphere(pressure_interval) # in J /m**2 / K
            array([   10244.89795918,   102448.97959184,  1024489.79591837])