Scratch for derived omega in hybrid coordinates

Define p=akP0+bkps(ϕ,λ) p = a_kP_0 + b_k p_s(\phi, \lambda) where we assume that we're working on a single model level.

ω\omega =DpDt=pt+vhηp+DηDtpη= \frac{\mathrm{D}p}{\mathrm{D}t} = \frac{\partial p}{\partial t} + \mathbf{v}_h \cdot \nabla_{\eta} p + \frac{\mathrm{D}\eta}{\mathrm{D}t} \frac{\partial p}{\partial \eta}
=0+vhηp0= 0 + \mathbf{v}_h \cdot \nabla_{\eta} p - 0
=uacosϕηλp+0ηϕp= \frac{u}{a\cos\phi} \frac{\partial}{\partial_{\eta} \lambda}p + 0 \cdot \frac{\partial}{\partial_{\eta} \phi}p
=uacosϕηλp= \frac{u}{a\cos\phi} \frac{\partial}{\partial_{\eta} \lambda}p
=uacosϕηλ(akp0+bkps(ϕ,λ))= \frac{u}{a\cos\phi} \frac{\partial}{\partial_{\eta} \lambda} \left(a_k p_0 + b_k p_s(\phi, \lambda) \right)
=bkuacosϕηλ(ps(ϕ,λ))= b_k \frac{u}{a\cos\phi} \frac{\partial}{\partial_{\eta} \lambda} \left(p_s(\phi, \lambda) \right)

Using the definition ps(ϕ,λ)=p0exp[gRd(τint,1(zs(ϕ,λ))τint,2(zs(ϕ,λ))IT(ϕ))] p_s(\phi, \lambda) = p_0 \exp \left[ -\frac{g}{R_d}\left(\tau_{\textrm{int}, 1}(z_s(\phi, \lambda)) - \tau_{\textrm{int},2}(z_s(\phi, \lambda))I_T(\phi)\right)\right]

We get that

ηλps \frac{\partial}{\partial_\eta \lambda} p_s=ηλp0exp[gRd(τint,1(zs(ϕ,λ))τint,2(zs(ϕ,λ))IT(ϕ))]= \frac{\partial}{\partial_\eta \lambda} p_0 \exp \left[ -\frac{g}{R_d}\left(\tau_{\textrm{int}, 1}(z_s(\phi, \lambda)) - \tau_{\textrm{int},2}(z_s(\phi, \lambda))I_T(\phi)\right)\right]
=gp0Rdexp[gRd(τint,1(zs(ϕ,λ))τint,2(zs(ϕ,λ))IT(ϕ))][([zτint,1](zs(ϕ,λ))IT(ϕ)[zτint,2](zs(ϕ,λ)))][ηλzs](ϕ,λ) = -\frac{gp_0}{R_d} \exp \left[ -\frac{g}{R_d}\left(\tau_{\textrm{int}, 1}(z_s(\phi, \lambda)) - \tau_{\textrm{int},2}(z_s(\phi, \lambda))I_T(\phi)\right)\right] \left[ \left(\left[\frac{\partial}{\partial z}\tau_{\textrm{int}, 1}\right](z_s(\phi, \lambda)) - I_T(\phi) \left[\frac{\partial}{\partial z}\tau_{\textrm{int},2}\right](z_s(\phi, \lambda))\right) \right]\left[\frac{\partial}{\partial_\eta \lambda}z_s\right](\phi, \lambda)
zτint,1(z) \partial_z \tau_{\mathrm{int},1}(z) =z1Γ[exp(ΓzT0)1]+z(T0TPT0TP)exp[(zgbRdT0)2] = \partial_z\frac{1}{\Gamma} \left[\exp \left(\frac{\Gamma z}{T_0} \right) - 1 \right] + z \left( \frac{T_0 - T_\mathrm{P}}{T_0T_\mathrm{P}} \right) \exp\left[ -\left(\frac{zg}{bR_dT_0} \right)^2\right]
zτint,2\partial_z \tau_{\mathrm{int},2} =zK+22(TETPTETP)zexp[(zgbRdT0)2] = \partial_z \frac{K+2}{2} \left(\frac{T_\mathrm{E} - T_\mathrm{P}}{T_\mathrm{E} T_\mathrm{P}} \right)z\,\exp \left[-\left(\frac{zg}{bR_dT_0} \right)^2 \right]