Non orographic gravity waves drag - Revision history

Dbardet: /* More advance description of the stochastic non-orographic gravity waves drag parametrization */

2025-04-30T09:22:25Z

‎More advance description of the stochastic non-orographic gravity waves drag parametrization

Dbardet: /* More advance description of the stochastic non-orographic gravity waves drag parametrization */

2025-04-30T09:18:48Z

‎More advance description of the stochastic non-orographic gravity waves drag parametrization

Dbardet: /* Description of the physical process */

2025-04-30T08:43:19Z

‎Description of the physical process

Dbardet at 08:38, 30 April 2025

2025-04-30T08:38:57Z

Dbardet at 08:36, 30 April 2025

2025-04-30T08:36:34Z

Dbardet: /* Description of the physical process */

2025-04-30T08:32:22Z

‎Description of the physical process

Dbardet: /* Underlying hypotheses and limitations */

2025-04-30T08:27:48Z

‎Underlying hypotheses and limitations

Dbardet: /* More advance description of the stochastic non-orographic gravity waves drag parametrization */

2025-04-30T08:16:30Z

‎More advance description of the stochastic non-orographic gravity waves drag parametrization

Dbardet: /* More advance description of the stochastic non-orographic gravity waves drag parametrization */

2025-04-30T08:06:11Z

‎More advance description of the stochastic non-orographic gravity waves drag parametrization

Dbardet: /* More advance description of the stochastic non-orographic gravity waves drag parametrization */

2025-04-30T08:03:10Z

‎More advance description of the stochastic non-orographic gravity waves drag parametrization

@@ Line 114: / Line 114: @@
-===== Reference papers =====
+'''Reference papers'''
 Lott et al. (2012) [https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2012GL051001]
 Lott and Guez (2013) [https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/jgrd.50705]
 [[Category: Generic-Model]] [[Category: Mars-Model]] [[Category: Venus-Model]]

@@ Line 112: / Line 112: @@
 The characteristics of each wave launched into the GCM are chosen at random with a prescribed probability distribution, the limits of which are the key parameters of the model.
 These are chosen on the basis of observational constraints (where available) and theoretical considerations.
 [[Category: Generic-Model]] [[Category: Mars-Model]] [[Category: Venus-Model]]

← Older revision		Revision as of 08:43, 30 April 2025
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	Inherited and adapted from Earth's model (F. Lott), this parametrization has been implemented in the Venus PCM (F. LOTT, and S. LEBONNOIS), in the Mars PCM (G.GILLI, F. FORGET and J.LIU), and in the Generic PCM (D.BARDET and J.LIU).		Inherited and adapted from Earth's model (F. Lott), this parametrization has been implemented in the Venus PCM (F. LOTT, and S. LEBONNOIS), in the Mars PCM (G.GILLI, F. FORGET and J.LIU), and in the Generic PCM (D.BARDET and J.LIU).
		+	However, we would like to draw the reader's attention to the fact that there may be some subtle differences from one model to another, which may be specific to Mars and/or Venus. But, the formalism in the Generic model is intended to remain very generic.

	== Dedicated flags to call in the ''callphys.def'' ==		== Dedicated flags to call in the ''callphys.def'' ==

← Older revision		Revision as of 08:38, 30 April 2025
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	These are chosen on the basis of observational constraints (where available) and theoretical considerations.		These are chosen on the basis of observational constraints (where available) and theoretical considerations.

−	[[Category: Generic-Model]] [[Category: Mars-~~model~~]] [[Category: Venus-~~model~~]]	+	[[Category: Generic-Model]] [[Category: Mars-Model]] [[Category: Venus-Model]]

← Older revision		Revision as of 08:36, 30 April 2025
Line 112:		Line 112:
	These are chosen on the basis of observational constraints (where available) and theoretical considerations.		These are chosen on the basis of observational constraints (where available) and theoretical considerations.

−	[[Category: Generic-Model]]	+	[[Category: Generic-Model]] [[Category: Mars-model]] [[Category: Venus-model]]

@@ Line 4: / Line 4: @@
 In the code, the FORTRAN file corresponding to this parametrization is <syntaxhighlight lang="fortran">nonoro_gwd_ran_mod.F90</syntaxhighlight>
-Inherited and adapted from Earth's model (F. Lott), Venus' model (F. LOTT, and S. LEBONNOIS) and Mars' model (G.GILLI, F. FORGET and J.LIU).
+Inherited and adapted from Earth's model (F. Lott), this parametrization has been implemented in the Venus PCM (F. LOTT, and S. LEBONNOIS), in the Mars PCM (G.GILLI, F. FORGET and J.LIU), and in the Generic PCM (D.BARDET and J.LIU).
 == Dedicated flags to call in the ''callphys.def'' ==

@@ Line 26: / Line 26: @@
 == Underlying hypotheses and limitations ==
-* input flux compensated in the deepest layers
+* Wave characteristic calculation using MOD
 * Variable EP-flux according to PBL variation (max velocity thermals)
-* reproductibility of the launching altitude calculation
+* Reproducibility of the launching altitude calculation
 == More advance description of the stochastic non-orographic gravity waves drag parametrization ==

@@ Line 80: / Line 80: @@
 In this scheme, $$\hat{\omega}_{n}$$ and the Eliassen Palm flow are randomly imposed at a given launch altitude $$z_0$$.
-A constant vertical viscosity $$\mu$$ (equation 4 in \cite{lott_2012}) controls the vertical distribution of gravity wave drag near the top of the model.
+A constant vertical viscosity $$\mu$$ (equation 4 in Lott et al. 2012) controls the vertical distribution of gravity wave drag near the top of the model.
 To move from one vertical level to the one just above, the Eliassen Palm flux is essentially conserved, but may undergo a small diffusivity, $$\nu = \mu/\rho_0$$, which can be included by replacing $$\Omega$$ by $$\Omega + i\nu m^{2}$$.
 This small diffusivity guarantees that the waves are finally dissipated on the last few levels of the model, if they have not been dissipated before (hence the division by the density $$\rho_0$$).

@@ Line 75: / Line 75: @@
 \end{equation}
 with $$k$$, $$l$$ the horizontal wavenumbers and $$w$$ the frequency of the vertical velocity field.
-This is included in the vertical wavenumber $$m = \frac{N \lvert \overrightarrow{k} \rvert}{\Omega} $$, according to the non-rotating WKB approximation, in the limit $$H \rightarrow \infty$$, with $$\Omega = v - \overrightarrow{k}\overrightarrow{u}$$ and $$N$$ the Brünt-Väisälä frequency \citep{lott_2012}.
+This is included in the vertical wavenumber $$m = \frac{N \lvert \overrightarrow{k} \rvert}{\Omega} $$, according to the non-rotating WKB approximation, in the limit $$H \rightarrow \infty$$, with $$\Omega = v - \overrightarrow{k}\overrightarrow{u}$$ and $$N$$ the Brünt-Väisälä frequency.
 In equation \ref{eq:GWD_EPflux}, $$\rho_{r}$$ is the density of the fluid at the reference pressure level $$P_r$$.
@@ Line 83: / Line 83: @@
 To move from one vertical level to the one just above, the Eliassen Palm flux is essentially conserved, but may undergo a small diffusivity, $$\nu = \mu/\rho_0$$, which can be included by replacing $$\Omega$$ by $$\Omega + i\nu m^{2}$$.
 This small diffusivity guarantees that the waves are finally dissipated on the last few levels of the model, if they have not been dissipated before (hence the division by the density $$\rho_0$$).
-Moreover, this new amplitude of the Eliassen Palm flux is limited to that produced by a saturated monochromatic $$\hat{\omega}_{s}$$ wave following \citep{lindzen_1981} :
+Moreover, this new amplitude of the Eliassen Palm flux is limited to that produced by a saturated monochromatic $$\hat{\omega}_{s}$$ wave following :
 \begin{equation}
@@ Line 97: / Line 97: @@
 Finally, the $$\rho^{-1}\delta_z \overrightarrow{F}^{z}_{n‘}$$ ($$n’$$=1, M) trends produced by the drag of the M generated gravity waves are calculated through the wind trends to be applied to the horizontal zonal wind.
 Since the $$\omega'_n$$ speeds are independent realisations, the mean trend produced is the average of these M trends.
-Thus, the average trend is first redistributed over the longest time scale $$\delta t$$ by rescaling it by $$\delta t / \Delta t$$ and then, the first-order autoregressive relationship (AR-1) described in \cite{lott_2012} is used as follows:
+Thus, the average trend is first redistributed over the longest time scale $$\delta t$$ by rescaling it by $$\delta t / \Delta t$$ and then, the first-order autoregressive relationship (AR-1) is used as follows:
 \begin{equation}

@@ Line 44: / Line 44: @@
 The $$\Delta t$$ life cycle of gravity waves, i.e. from their generation to their break-up, is significantly longer than the $$\delta t$$ time step of the GCM.
-On Earth, gravity wave theory indicates that atmospheric disturbances induced by convection have life cycles of about 1 day. \citep{lott_2013}.
+On Earth, gravity wave theory indicates that atmospheric disturbances induced by convection have life cycles of about 1 day.
 The spectrum, made up of triple discrete Fourier series, is discretised into 770 stochastic harmonics ($$\approx$$ M $$\times \Delta t/\delta t$$) which contribute to the wave field each day and at a given horizontal grid point.