<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def dewpoint_rh(temperature, rh):
 r"""Calculate the ambient dewpoint given air temperature and relative humidity. Parameters temperature : `pint.Quantity` Air temperature rh : `pint.Quantity` Relative humidity expressed as a ratio in the range 0 < rh <= 1 Returns ------- `pint.Quantity` The dew point temperature See Also -------- dewpoint, saturation_vapor_pressure """

    if np.any(rh > 1.2):
        warnings.warn('Relative humidity >120%, ensure proper units.')
    return dewpoint(rh * saturation_vapor_pressure(temperature))