/**
\page GFS_NOAH GFS Noah Land Surface Model
\section des_noah  Description
 Land-atmosphere interactions are a main driver of Earth's surface
 water and energy budgets. The importance of the land surface is
 rather intuitive, and has been demonstrated not only in terms of
 predictability on daily to seasonal timescale (Betts et al. (2017) \cite betts_et_al_2017), but also in terms
 of influencing extremes such as drought and heatwaves (Paimazumder and Done (2016) \cite paimazumder_and_done_2016),
 PBL evolution and cloud
 formation (Milovac et al. (2016) \cite milovac_et_al_2016) and afternoon
 convection (Guillod et al. (2015) \cite guillod_et_al_2015), and
 tropical cyclone re-intensification (Andersen and Shepherd (2014) \cite andersen_and_shepherd_2014). 
 Other linkages, such as the role of soil
 moisture (SM) or vegetation heterogeneity in mesoscale circulation
  (Hsu et al. (2017) \cite hsu_et_al_2017) and planetary waves (Koster et al. (2014) \cite koster_et_al_2014), 
 and those driven by land use
 and land cover change or management (Hirsch et al. (2015) \cite hirsch_et_al_2015; 
 Findell et al. (2017) \cite findell_et_al_2017) are topics of active research.

 Figure 1 is a schematic of local land-atmosphere interactions in a
 quiescent synoptic regime, including the soil moisture-precipitation
 (SM-P) feedback pathways (Ek and Mahrt (1994) \cite ek_and_mahrt_1994; Ek and Holtslag (2004) \cite ek_and_holtslag_2004 ).  Solid arrows indicate a positive feedback
 pathway, and large dashed arrows represent a negative feedback, while
 red indicates radiative, black indicates surface layer and PBL, and
 brown indicates land surface processes. Thin red and grey dashed lines
 with arrows also represent positive feedbacks. The single horizontal
 gay-dotted line (no arrows) indicates the top of the PBL, and the seven
 small vertical dashed lines (no arrows) represent precipitation
 \image html Noah_LA_interaction.png "Figure 1: Local Land-atmosphere Interaction (courtesy of Michael Ek)" width=900
Recently, the land surface updates in 2017 GFS operational physics includes:
 - IGBP 20-type 1-km land classification
 - STASGO 19-type 1-km soil classification
 - MODIS-based snow free albedo
 - MODIS-based maximum snow albedo
 - Diurnal albedo treatment
 - Unify snow cover, albedo between radiation and land surface model
 - Increase ground heat flux under deep snow
 - Upgrade surface layer parameterization scheme \ref GFS_SFCLYR to modify the roughness-length formulation and introduce a stability parameter constraint in the Monin-Obukhov similarity theory to prevent the land-atmosphere system from fully decoupling leading to excessive cooling of 2m temperature during sunset
 \image html land_dataset.png "Figure 2: Land Data Sets Used in NCEP Modeling Systems" width=900

\section intra_noah Intraphysics Communication
- \ref arg_table_lsm_noah_run

\section gen_al_noah General Algorithm
- lsm_noah::lsm_noah_run
*/