The northward moving meridional wind is directed countergradient with respect to the maximum values of absolute vorticity
向北移动的经向风由绝对速度的最大值逆梯度引导.
这个句子使用了被动语态,主语是The northward moving meridional wind ,谓语部分是 is directed ；with respect to the maximum values of absolute vorticity在句子中充当方式状语.