Ageostrophic风仅仅是组件的实际非地转风。换句话说,考虑到实际风($ \ mathbf v $)和地转风($ \ mathbf v_g $), ageostrophic风($ \ mathbf v_a $)是向量之间的区别。ageostrophic风代表摩擦和和其他影响。比如,负责表面风穿越等压线,而不是跟着他们。$ $ \ mathbf v_a = \ mathbf v - \ mathbf v_g $ $ * * *准地转是指一组修改做出许多假设方程,近似和忽视由于扩展条款。方程仅适用罗斯比数字远低于1 (Ro < < 1)其中包括:美元——忽视平流\ mathbf v_a美元——忽视平流垂直速度,忽视美元的时间趋势\ mathbf v_a——忽视平流\美元mathbf v_a由美元\ mathbf v_g与β-取代f $美元平面近似(f = f_0 +β\ y)美元——忽略摩擦水平不变的静态稳定性(\σ美元)从无摩擦水平动量方程得到的“Q-G”方程:一个热力学能量方程,涡度方程和ω方程。Q-Gω方程:$ $ \离开(\微分算符^ 2 _p + \ dfrac {f ^ 2 _0}{\σ}\ dfrac{\部分^ 2}{\部分p ^ 2} \) \ω= - \ dfrac {f_0}{\σ}\ dfrac{\部分}{\部分p} \离开[- \ mathbf v_g \ cdot \ mathbf \ nabla_p (\ zeta_g + f) \] + \ dfrac {R}{\σp} \离开[- \微分算符^ 2 _p (- \ mathbf v_g \ cdot \ mathbf \ nabla_p T) \右]$ $第一项的皇家垂直变化的地转绝对涡度平流地转风。正涡度平流随高度增加导致向上的垂直运动。负涡度平流随高度增加导致向下的垂直运动。第二项上的皇家有关温度平流的地转风。 Cool air advection (CAA) correlates with upward vertical motion. This is the traditional form of the equation and other forms exist to aid in diagnosing vertical motion with specific variables (e.g. the Sutcliffe-Trenberth recasts the equation using the thermal wind and Hoskins et al. (1978) defines the equation in terms of $\vec Q$, "Q vectors"). There isn't much NWP utility to the Q-G equations with todays computers, but they are good for diagnosing vertical motion in hand map analysis. (will add the QG chi equation here) Further reading: - [Real-time anlyses and forecasts of the QG diagnostic equations][1] - [The QG equations][2] (Thanks @DrewP84) - [An abbreviated derivation][3] [1]: http://www.mmm.ucar.edu/people/tomjr/files/realtime/diagnostics.html [2]: http://www.geos.ed.ac.uk/~rharwood/teaching/phys4/dynamics/ch_13.pdf [3]: http://en.wikipedia.org/wiki/Quasi-geostrophic_equations