def plot_vertical_momentum_flux(self,data,xdata,terrain):
met=data[['wdir','wspd','wvert','lats','lons']]
# topo=np.asarray(Terrain.get_topo(lats=met['lats'], lons=met['lons']))
topo2=np.asarray(Terrain.get_topo2(lats=met['lats'], lons=met['lons'],terrain=terrain))
u_comp,v_comp = get_wind_components(met.wspd,met.wdir)
w_comp=met.wvert
u_moflux = pd.rolling_cov(u_comp, w_comp, 60, center=True)
v_moflux = pd.rolling_cov(v_comp, w_comp, 60, center=True)
fig, ax = plt.subplots(2,1, sharex=True)
l1=ax[0].plot(xdata,u_moflux,label='U-moment')
l2=ax[0].plot(xdata,v_moflux,label='V-moment')
ax[0].set_ylim([-1.0,1.0])
ax[0].set_ylabel('Vertical momentum flux [ m2 s-2]',color='b',fontsize=15)
# plt.legend(handles=[l1,l2])
ax[0].legend()
spl=UnivariateSpline(xdata[::5],topo2[::5],k=5)
xsmooth=np.linspace(0.,xdata[-1],int(len(xdata)))
ysmooth=spl(xsmooth)
ysmooth[ysmooth<0]=0
ax[1].plot(xsmooth, ysmooth,color='black')
ax[1].set_xlabel('Distance from flight start [km]',fontsize=15)
plt.draw()
