It is shown that, over the grid-points where orography height is negative, there exists false sensible heat source that leads to warmer temperature and higher geopotential height.

• 本文通过理论分析，从多圈层相互作用的角度揭示了谱模式中负地形通过产生虚假的感热源而导致模式系统误差的产生的原因。