如果我们在北半球,有一个高压点,用H表示,有一个低压点,用L表示,(为了简单起见,假设它们在纬度上,即H在西方,L在东方)。压力梯度力会驱使风从H到L,因为我们在北半球,风会被科里奥利力向右偏转。< / p >
The wind began with a velocity $\vec{V}$ initially directed towards L (that is in the direction of pressure gradient force P), but due to Coriolis force C, at right angles to the velocity, it turns rightwards and we get a geostrophic wind, that is a wind blowing parallel to isobars. But in all this, when did C get cancelled with P?
$\vec{V'}$是问题图中所示情况之后的速度。因此,这就是C和P如何相互抵消
如果一个压力梯度力凭空出现,那么它将像你建议的那样:
So initially $\overrightarrow{c}$ and $\overrightarrow{P}$ don't cancel at all, but as the wind turns, more and more of them cancels until it reaches a steady state when $\overrightarrow{c}$ and $\overrightarrow{P}$ are completely equal and opposite and so the velocity vector is unchanging (in magnitude and direction) as well.