/**
\page GFS_SAMFshal GFS SAS-based Mass-Flux Scheme for Shallow convection (sa-MF)

\section des_shal Description
 \ref SAMF_shal is an updated version of the previous mass-flux shallow
 convection scheme with scale and aerosol awareness and
 parameterizes the effect of shallow convection on the environment.
 \ref SAMF_shal is similar to \ref SAMFdeep
 but with a few key differences. First, no quasi-equilibrium assumption
 is used for any grid size and the shallow cloud base mass flux is
 parameterized using a mean updraft velocity. Further, there are no
 convective downdrafts, the entrainment rate is greater than for deep
 convection, and the shallow convection is limited to not extend over
 the level where \f$p=0.7p_{sfc}\f$. The paramerization of scale and
 aerosol awareness follows that of the SAMF deep convection scheme,
 although it can be interpreted as only having the "static" and "feedback" control
 portions, since the "dynamic" control is not necessary to find the 
 cloud base mass flux. 

 The previous version of the shallow convection scheme (shalcnv.f)
 is described in Han and Pan (2011) \cite han_and_pan_2011 and differences
 between the shallow and deep convection schemes are presented in
 Han and Pan (2011) \cite han_and_pan_2011 and Han et al. (2017) \cite han_et_al_2017 . 
 Details of scale- and aerosol-aware parameterizations
 are described in Han et al. (2017) \cite han_et_al_2017 .

 In further update for FY19 GFS implementation, interaction with turbulent
 kinetic energy (TKE), which is a prognostic variable used in a scale-aware
 TKE-based moist EDMF vertical turbulent mixing scheme, is included.
 Entrainment rates in updrafts are proportional to sub-cloud mean TKE. TKE is
 transported by cumulus convection. TKE contribution from cumulus convection
 is deduced from cumulus mass flux. On the other hand, tracers such as ozone
 and aerosol are also transported by cumulus convection.

 To reduce too much convective cooling at the cloud top, the convection
 schemes have been modified for the rain conversion rate, entrainment and
 detrainment rates, overshooting layers, and maximum allowable cloudbase mass
 flux (as of June 2018).


\section intr_shal Intraphysics Communication
\ref arg_table_samfshalcnv_run

\section gen_shal General Algorithm
\ref gen_samfshalcnv


*/