initialise Subroutine

  subroutine initialise(this, ice, sub_ice)
    !* Author: Christopher MacMackin
    !  Date: November 2016
    !
    ! Initialise a cryosphere object from the provided
    ! components. This object will model the evolution of a
    ! glacier/ice shelf/ice sheet and its surroundings.
    !
    class(cryosphere), intent(out) :: this
    class(glacier), allocatable, intent(inout)       :: ice
      !! An object modelling the ice sheet or shelf component of this
      !! system. Will be deallocated on return.
    class(basal_surface), allocatable, intent(inout) :: sub_ice
      !! An object modelling the component of this system beneath the
      !! ice. Will be deallocated on return.
    call move_alloc(ice, this%ice)
    call move_alloc(sub_ice, this%sub_ice)
    this%time = 0.0_r8
    this%first_integration = .true.
#ifdef DEBUG
    call logger%debug('cryosphere','Instantiated new cryosphere object.')
#endif
  end subroutine initialise