CHANGES

 CM1 Numerical Model, release 19.10  (cm1r19.10)
 4 March 2020

 Summary of changes.

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1.  New options/features.


 - Added the RRTMG radiation scheme. 
   (Set radopt = 2 to use this scheme.) 


 - Added code to calculate and write out turbulence diagnostics for 
   large-eddy simulations (LES) and direct numerical simulations (DNS) 
   during CM1 integration.  Variables include domain-averaged vertical 
   profiles, variance profiles, resolved/parameterized vertical flux 
   profiles, etc.  See namelist variable "doturbdiag" and see output 
   file contents for more information.


 - Added code to calculate and write out azimuthally averaged fields 
   during CM1 integration.  This option is useful for simulations of 
   rotating flow (eg, tropical cyclones, tornadoes).  See namelist 
   variable "doazimavg" and see output file contents for more information.


 - Added the option for CM1 users to specify the location of grid points
   (including vertical levels) in an external ascii file.  In this case, 
   users do not need to modify CM1 source code (eg, param.F) to specify 
   the distribution of vertical levels, or the location of horizontally 
   stretched grid points.  Also, users do not need to use the pre-defined 
   stretching functions within CM1.  See options stretch_x=3, stretch_y=3,
   stretch_z=3 in README.namelist for more information.  


 - Added new advection options.  In addition to the existing schemes 
   from previous versions of CM1 (5th-oder, 6th-order, and WENO-5)
   users can now use:  2nd-order, 3rd-order, 4th-order, 7th-order, 
   8th-order, 9th-order, 10th-order, WENO-3, WENO-7, WENO-9.  
   See README.namelist for more information.


 - Added a new variable to the CM1 namelist called "cm1setup" which makes 
   it easier to configure and use CM1.  The focus is on how turbulence 
   is handled.  Valid options are:  

    0 = no subgrid turbulence model & no explicit diffusion
        (essentially integrate the Euler equations)

    1 = large-eddy simulation (LES)
        (integrate the filtered Navier-Stokes equations, aka, LES equations)

    2 = mesoscale modeling with planetary boundary layer (PBL) parameterization
        (essentially uses Reynolds-averaged Navier-Stokes, RANS, equations)

    3 = direct numerical simulation (DNS)
        (integrate Navier-Stokes equations with constant viscosity/diffusivity)


 - Added all pre-configured namelists and input files in a new subdirectory 
   within the CM1 distribution.  See the "run/config_files" subdirectory for 
   more information. 


 - Direct Numerical Simulations (DNS) with CM1 can now make use of terrain. 


 - Added several well-documented and common "test cases" from the literature.
   (See variable "testcase" in README.namelist)  These cases use simplified 
   physical parameterizations and/or specified tendency terms and/or special
   settings, which are coded into CM1 and used only when appropriate.  Options
   for "testcase" are:

    0  =  Default.  (no special physics, forcings, or configutation)
          - Most users will use testcase=0.

    1  =  Convective Boundary Layer (CBL) using Large Eddy Simulation (LES)
          - Based on Sullivan and Patton (2011, JAS, pg 2395)
          - See namelist.input in directory run/config_files/les_ConvBoundLayer

    2  =  Sheared Boundary Layer (SBL) using Large Eddy Simulation (LES)
          - (i.e., neutral boundary layer)
          - Based on Moeng and Sullivan (1994, JAS, pg 999)
          - See namelist.input in directory run/config_files/les_ShearBoundLayer

    3  =  Shallow cumulus clouds using Large Eddy Simulation (LES)
          - Based on Siebesma et al (2003, JAS, pg 1201)
          - See namelist.input in directory run/config_files/les_ShallowCu

    4  =  Nonprecipitating stratocumulus clouds using Large Eddy Simulation (LES)
          - Based on Stevens et al (2005, MWR, pg 1443)
          - See namelist.input in directory run/config_files/les_StratoCuNoPrecip

    5  =  Drizzling stratocumulus clouds using Large Eddy Simulation (LES)
          - Based on Ackerman et al (2009, MWR, pg 1083)
          - See namelist.input in directory run/config_files/les_StratoCuDrizzle

    6  =  Hurricane Boundary Layer (HBL) using Large Eddy Simulation (LES)
          - Based on Bryan et al (2017, BLM, pg 475)
          - See namelist.input in directory run/config_files/les_HurrBoundLayer


 - Added pre-configured settings and namelist.input for a Direct Numerical 
   Simulation (DNS) case based on Rayleigh-Benard convection, following 
   Moneg and Rotunno (1990, JAS).  See files in directory 
   run/config_files/dns_RayleighBenard for more information. 


 - Added the option to use a vertically explicit formulation for turbulence
   tendencies in the CM1 subgrid turbulence/diffusion scheme.  (Does not apply 
   to ipbl=1, i.e., the YSU PBL scheme.)  The default option is still to use 
   vertically implicit diffusion (doimpl=1), which is absolutely stable, but
   now users can use doimpl=0 for simple explicit diffusion calculations.


 - Renamed the "perturbation Coriolis" scheme from "pertcor" to "lspgrad" to 
   acknowledge that this method actually applies a large-scale pressure 
   gradient tednency to the horizontal velocity equations.  Also added two 
   new options:  lspgrad=2, which allows the user to specify geostrophic wind
   profiles that differ from the base-state wind profiles;  and lspgrad=3, 
   which applies a gradient-wind balance formulation to determine large-scale 
   pressure gradient (following Bryan et al, 2017, BLM).  See README.namelist 
   file for more information.   


 - Added several options to the CM1 surface layer scheme (sfclay=1) to 
   more easily accommodate idealized simulations:

     set_flx - impose constant surface heat fluxes
     cnst_shflx  - value for surface sensible heat flux for set_flx=1
     cnst_lhflx - value for surface latent heat flux for set_flx=1

     set_znt - impose constant surface roughness length
     cnst_znt - value of surface roughness length for set_znt=1

     set_ust - impose constant surface friction velocity
     cnst_ust - value of surface friction velocity for set_ust=1


 - Added the ability to run large eddy simulations (LES) without an explicit
   subgrid turbulence model (often called Implicit LES or ILES) without 
   requiring users to modify CM1 code.  Simply set cm1setup=1 with sgsmodel=0 
   to run CM1 in this configuration. 


 - New output variables:

       2D:  - Convective Available Potential Energy (CAPE)
              (see output_cape in namelist.input)

            - Convective Inhibition (CIN)
              (see output_cin in namelist.input)

            - Lifted Condensation Level (LCL)
              (see output_lcl in namelist.input)

            - Level of Free Convection (LFC)
              (see output_lfc in namelist.input)

            - Precipitable water
              (see output_pwat in namelist.input)

            - Liquid water path and cloud water path
              (see output_lwp in namelist.input)


       3D:  - Budget variables:  includes tendencies due to advection, turbulence,
              microphysics, radiation, pbl scheme, buoyancy, pressure-gradient 
              acceleration, etc, as calculated within CM1.  See output files for 
              more information.

              (see output_thbudget, output_qvbudget, output_ubudget,
               output_vbudget, and output_wbudget in namelist.input)


       stats:  - Max/Min vertical velocity at five different levels: 
                 0.5, 1, 2.5, 5, 10 km AGL 
                   (see output_wlevs in namelist.input)


   -------------------
    cm1r19.2:

 - For simulations with Coriolis acceleration (icor=1), added the ability 
   to use a beta plane.  The f plane approximation is still used by 
   default.  See the variable "betaplane" in the param.F file. 

 - Added the ability to turn off the Rayleigh damper near lateral boundaries
   when hrdamp=1.  See variables hrdamp_west, hrdamp_east, hrdamp_south, and 
   hrdamp_north in the param.F file. 

 - Added subgrid-scale tke budget terms and a preliminary version of 
   resolved-scale tke budget terms to the diagnostic turbulence code
   (doturbdiag = .true.).


   -------------------
    cm1r19.3:

 - Added the updraft nudging initialization scheme of Naylor and Gilmore 
   (2012, MWR, pg 3699).  See iinit=12 in init3d.F for more information.

 - The anelastic and incompressible solvers (psolver=4,5) can now be used 
   with open lateral boundary conditions.  These codes have also been
   optimized for efficiency, and the pressure variable "phi" is now included 
   in output files. 


   -------------------
    cm1r19.4:

 - Added the option to either apply the Rayleigh damper to the perturbation 
   from the base state (irdamp,hrdamp = 1, which was the only option in 
   CM1 previously) or to apply Rayleigh damper to the perturbation from the 
   domain-average profiles (irdamp,hrdamp = 2).  The new option is useful 
   for very long simulations (roughly, >10 days). 

 - Added the RICO precipitating cumulus test case as testcase=7.  See 
   README file in the run/config_files/les_ShallowCuPrecip subdirectory
   and/or VanZanten et al (2011, JAMES) for more information. 

 - Added a radiative-convective equilibrium (RCE) test case as testcase=8.
   See README file in the run/config_files/cpm_RadConvEquil subdirectory
   and/or Bretherton et al (2005, JAS) for more information. 

 - Added a single-column version of the hurricane boundary layer test case
   (testcase=6).  See README file in the run/config_files/scm_HurrBoundLayer 
   subdirectory for more information. 

 - When writing budgets variables (output_thbudget, output_ubudget, etc)
   and an odd-ordered advection scheme is used (3rd, 5th, 7th, 9th-order 
   advection) or a WENO advection scheme is used, then the advection 
   tendencies are separated into a non-diffusive component and the component 
   attributable to implicit diffusion.  
   (Note: in some previous versions of CM1, implicit diffusion tendencies 
    were previously written when output_impdiften=1.  These output fields 
    have now been restored as part of the "budget" output variables introduced
    in cm1r19.) 

 - Explicit diffusion tendencies are now added to the budget variables, 
   including tendencies from the sixth-order horizontal diffusion scheme 
   (idiff >=1 with difforder=6). 

 - Added the option to write pressure decomposition variables to output files.  
   Three diagnostic variables are determined: buoyancy pressure perturbation, 
   non-linear dynamic pressure perturbation, and linear dynamic pressure 
   perturbation (based on the base-state wind profiles). 
   Note: this code does not work with distributed-memory parallelization (MPI)
   yet.  
   See output_pdcomp in the namelist and README.namelist for more info.

 - Added the ability to more easily write any output field to a CM1 output 
   file.  Specifically, the arbitrary arrays "out3d" and "out2d" have been 
   added to CM1.  These arrays are allocated at the beginning of a CM1 
   simulation, and have arbitrary sizes based on the "nout3d" and "nout2d" 
   variables which can be set near the top of the cm1.F file.  As long as 
   nout3d and/or nout2d are >= 1, then the contents of these arrays will be 
   added to CM1 output files, and named "out1" and "out2" and "out3" etc. 
   The only thing the users needs to do is:  1) set values for nout3d and 
   nout3d in cm1.F;  2) make sure the out(i,j,k,1) and out(i,j,k,2) etc 
   arrays are filled with the information/variable/diagnostic that the 
   use wants to output.  See also the brief description near the top of 
   the cm1.F file.  

 - Added additional variables to CM1 output files:

      - arbitrary 3d and 2d output arrays (see item above)
      - vgrad (gradient wind) when the axisymmetric model is used (axisymm=1)
      - wspd, the wind speed in the surface layer (including gust) used to 
        calculate surface fluxes for some surface-layer schemes
      - pressure decomposition variables (see "pressure decomposition" item
        above;  user must set output_pdcomp in the namelist;  (Note: does not
        work with distributed memory MPI simulations, yet)

 - Added additional variables to the azimuthal averaging code:

      - satfrac (fraction of saturated gridpoints)
      - vgrad (gradient wind)
      - buoyancy (wrt base state)
      - pressure decomposition fields (eg, buoyancy and dynamic prs perts)
      - vertical accel due to pressure decomposition fields

 - Added many, many new variables to the turbdiag (turbulence diagnostics)
   output files.  See cm1out_turbdiag* files for more information. 

 - Added max/min PBL depth as a "stats" variable.


   -------------------
    cm1r19.5:

 - Added even more variables to the turbdiag (turbulence diagnostics)
   output files.  See cm1out_turbdiag* files for more information.


   -------------------
    cm1r19.6:

 - Added isnd=17 option, which is the same as isnd=7 (external file) except 
   the wind profiles are neglected, and the iwnd option can be used to specify
   base-state/initial wind profile.  See README.namelist for more information.

 - Added several options to the tropical cyclone initialization scheme 
   (iinit=7), including the ability to locate the vortex anywhere in the 
   domain, and the option to use a modified Rankine analytic vortex.  See the
   iinit=7 section of init3d.F for more information.

 - Added the ability to use Thompson microphysics scheme with eqtset=2 (the
   energy-conserving equations that account for the heat capacity of 
   hydrometeors).

 - When using the YSU PBL scheme, all three eddy diffusivities (for heat, 
   moisture, and momentum) are now included in output files. 


   -------------------
    cm1r19.7:

 - (nothing new)


   -------------------
    cm1r19.8:

 - Added new stats output variables:

      - maximum surface precipitation rate
      - level of maximum/minimum vertical velocity
      - level of maximum/minimum horizontal wind speed

 - Added new turbdiag output variables:

      - maximum and minimum vertical velocity
      - maximum and minimum horizontal wind speed
      - maximum and minimum vertical vorticity
      - total upward and downward mass flux profiles
      - domain-average profiles of passive tracers and fluxes when iptra=1

 - Added output variables:

      - surface roughness length for temperature and moisture when
        sfcmodel = 2,3. 

 - Added ability to nudge inflow velocity profiles towards base-state 
   profiles.  This option can keep inflow profiles nearly constant 
   throughout simulations.  See the variables "nudgeobc" and "alphobc"  
   in README.namelist for more information.

 - Added stretch_z = 4 option, which allows users to specify the model's 
   full levels (aka, w levels) via an external file, input_grid_z.  See
   the variable "stretch_z" in README.namelist for more information. 


   -------------------
    cm1r19.9:

 - Added the GFS-EDMF planetary boundary layer scheme (ipbl=3) and the 
   GFDL surface layer scheme (sfcmodel=4).  These are the parameterizations
   used in HWRF_v4.0a, and default settings are the same (as much as 
   possible); see the section of code labeled "hwrf parameters" in turb.F
   for more information. 

 - Added the ability to use the output_interp option with netcdf-format 
   files.  

 - Added even more variables to the turbdiag (turbulence diagnostics)
   output files.  See cm1out_turbdiag*.ctl files for more information.

 - Added testcase=9, the stable boundary-layer LES case from Beare et al. 
   (2006, BLM).  See files in the subdirectory run/config_files/les_StableBoundLayer
   for more information.

 - Added testcase=10, an extension of testcase=6 that allows for surface 
   fluxes of heat and moisture, and allows for stratification.  Experimental:
   use with caution.  


   -------------------
    cm1r19.10:

 - Added the MYNN (Mellor-Yamada-Nakanishi-Niino) planetary boundary layer 
   scheme.  ipbl=4 uses MYNN level 2.5, ipbl=5 uses MYNN level 3

 - Added the MYNN surface layer scheme (sfcmodel=6). 

 - Added another case to the "config_files" subdirectory, which uses 
   the testcase=10 configuration.  See the README file in 
   scm_HurrBoundLayer_tqnudge subdirectory for more information. 


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2.  Changes, fixes, modifications, etc.

 - The CM1 solver was simplified, slightly, to increase performance. 
   A roughly 10% decrease in computational cost may be seen on some 
   platforms and with some compilers.  Largest improvement (for cm1r19
   relative to cm1r18) seems to come when using the GNU compiler 
   (gfortran).
   (solve.F, sound.F, sounde.F)

 - The calculation of horizontal pressure gradient terms with terrain-
   following coordinates (terrain_flag = .true.) has been substantially 
   improved.  
   (many files)

 - Some calls to subroutines that are not directly related to integrating 
   CM1 (eg, statpack, writeout) were moved out of solve.F;  the cm1.F 
   file was re-organized to accommodate this change, and to simpify I/O 
   routines and diagnostic code.  Long-time users of CM1 will need to 
   look in cm1.F instead of solve.F to find certain code. 
   (many files)

 - The cm1 "include" directory was eliminated.  Instead, more Fortran 
   modules are used to specify variables and constants.  See, especially, 
   the new files input.F and constants.F in the "src" directory.  
   (many files)

 - Made many changes to the I/O routines to make it easier to write out 
   new variables and diagnostics.  See, especially, the new *_output, 
   *_stat, and *_prcl arrays in cm1.F, writeout.F, writeout_nc.F, 
   statpack.F, and parcel.F.  
   (many files)

 - The cm1 variable "nsound" has been removed from the namelist.  Users no 
   longer need to specify "nsound" (the number of "small" time steps per 
   "big" time step), which is now calculated diagnostically during CM1
   integrations.  
   (many files)

 - To make the parcel code run much faster, the array structure of certain 
   variables (eg, pdata) was re-ordered.  The code also uses different 
   MPI calls for distributed-memory parallelization.
   (many files, including parcel.F)

 - Made some minor modifications / bug fixes in the Morrison microphysics 
   code.  
   (morrison.F)

 - The Thompson microphysics code has been updated.  It is now the same 
   version that is in WRF 3.9.  
   (thompson.F, solve.F)

 - The YSU PBL scheme has been updated. 
   (ysu.F)

 - A potentially major bug when using the YSU PBL scheme with the 
   axisymmetric version of CM1 (axisymm=1) has been flushed out and fixed. 
   The turbulent tendency to tangential velocity was underestimated 
   previously. 
   (turb.F)

 - The CM1 variable "eqtset" (for using traditional or Bryan-Fritsch moist 
   equation sets) has been fully incorporated into the calculations of 
   radiation tendencies.  Previously, only the eqtset=2 option was 
   technically valid for CM1 simulations with radiation. 
   (many files)

 - Fixed a minor bug in the calculation of potential vorticity (PV). 
   The bug only affected simulations without terrain, and did not affect 
   model integrations (i.e., it was only a problem for output files). 
   Thanks to Xiaoming Shi (Univ Cal-Berkeley) for finding this bug. 
   (misclibs.F)

 - Fixed some problems with the standard text output at the beginning of 
   simulations.  (Does not affect simulations;  merely affects some text 
   diagnostics.)  Thanks to Teddie Keller of NCAR/RAL for finding these 
   bugs.  
   (param.F, base.F)

 - Updated the CM1 Makefile.  Default settings are appropriate for NCAR's 
   new supercomputer, cheyenne. 
   (Makefile) 


   -------------------
    cm1r19.2:

 - Updated the NSSL microphysics code.  See documentation near the top of 
   module_mp_nssl_2mom.F for more information.  Thanks to Ted Mansell of 
   NOAA/NSSL. 
   (module_mp_nssl_2mom.F)

 - Fixed a bug with the goddard microphysics module that was causing certain 
   compilers to crash.  (Does not change results.)  Thanks to Dan Stern of NRL.
   (goddard.F)

 - Fixed a bug with the netcdf-format stats output routine, which was 
   crashing for long simulations.  (Does not change results.)  Thanks to Dan 
   Kirshbaum of McGill University. 
   (writeout_nc.F)

 - Fixed a bug with the RRTMG shortwave radiation code that was causing  
   some long simulations to crash.  Thanks to Stipo Sentic of New Mexico Tech.
   (module_ra_rrtmg_sw.F)

 - Tweaked the Deardroff/Lilly TKE subgrid model for LES (sgsmodel=1) to 
   better handle the subgrid length scale in stable conditions.  Thanks to 
   Xiaoming Shi of the University of California Berkeley. 
   (turb.F) 

 - Fixed a bug with the diagnostic calculation of horizontal pressure gradient
   (output_ubudget = 1 and/or output_vbudget = 1) when using terrain.  Does 
   not affect simulations (only affects diagnostic budget output). 
   (solve.F)

 - Fixed some minor bugs with I/O when the output frequency is not exactly 
   divisible by the time step.  No change on results;  merely affects the 
   times when output is written. 
   (cm1.F)


   -------------------
    cm1r19.3:

 - Updated the Thompson microphysics scheme (ptype=3).  The version is now
   the same as that in WRF3.9.1.
   (thompson.F)

 - Updated the revised surface layer scheme (sfcmodel=3).  The version is now
   the same as that in WRF3.9.1.
   (sfclayrev.F)

 - Fixed a few minor bugs with the compressible-Boussinesq solver (psolver=6)
   and added the pressure variable "phi" to output files.
   (soundcb.F, writeout.F, restart.F)


   -------------------
    cm1r19.4:

 - Added more documentation for the input_sounding option (isnd=7).  See the 
   relevant section of code in base.F or the webpage 

       http://www2.mmm.ucar.edu/people/bryan/cm1/soundings/ 

   for more information.  
   (base.F)

 - Fixed a bug with the compressible-Boussinesq solver (psolver=6) when using
   terrain.
   (soundcb.F)

 - Modified the calculation of saturation vapor pressure for very cold 
   temperatures (< -100 C) to avoid Bad Things.  Only relevant for very
   deep domains (> 30 km).
   (many files)

 - Replaced the old crude calculation of PBL depth with a slightly less crude
   calculation based on critical Richardson number.  The new code prevents 
   ridiculously large values (> 20 km) of PBL depth.  Note1: as before, use 
   this diagnostic code with caution.  Note2: diagnosed PBL depth is 
   unchanged when using the YSU PBL scheme (ipbl=1). 
   (turb.F, sfcphys.F)

 - For calculation of squared moist Brunt-Vaisala frequency (nm array) the 
   saturation condition is changed from simply the presence of qc and/or qi 
   to a condition based on saturation state.  This changed was made primarily 
   because there are regions where the air can very dry (wrt saturation) but 
   can have cloud ice due to sedimentation of qi from above.  This change 
   affects all the LES subgrid turbulence parameterizations, as well as 
   ipbl = 1,2 (YSU and simple CM1 PBL schemes). 
   (turb.F, ysu.F)

 - Physical constants in RRTMG radiation scheme are changed to be consistent 
   with the rest of CM1. 
   (module_ra_rrtmg_lw.F, module_ra_rrtmg_sw.F, radiation_driver.F)

 - OpenMP parallelization (shared memory parallelization) can now be used for 
   the RRTMG radiation scheme. 
   (module_ra_rrtmg_lw.F, module_ra_rrtmg_sw.F, radiation_driver.F)

 - Fixed a bug that didn't allow the simple CM1 PBL scheme (ipbl=2) to be 
   used without moisture (imoist=0).  Thanks to Thomas Kloetzke of the 
   University of Queensland.  
   (param.F)

 - Fixed a bug with netcdf-format restart files and sfcmodel=1.  Thanks to 
   Dan Stern (NRL). 
   (writeout_nc.F)

 - Other minor bug fixes have been applied.  
   (solve.F, turb.F, cm1.F, etc)


   -------------------
    cm1r19.5:

 - Adaptive time stepping (adapt_dt=1) has been modified to account for 
   numerical stability of horizontal turbulence/diffusion.  This change will 
   not affect most simulations, but fixes a problem with CM1 crashing for very 
   strong hurricanes.  
   Thanks to Dan Stern of UCAR/NRL. 
   (cm1.F, misclibs.F, turb.F)

 - Some code has been rearranged to increase efficiency.  No change on results,
   but on some platforms run times will be lower by about 5% (relative to 
   cm1r19.4). 
   (many files)

 - The YSU PBL (ipbl=1) and the revised surface layer scheme (sfcmodel=3) can
   now be parallelized using OpenMP (shared-memory parallelization).  
   (ysu.F, sfcmodelrev.F)

 - A few bugs were fixed for set_ust=1 (specified surface friction velocity). 
   The retrieved values of roughness length and drag coefficient are now 
   accurate.  Minor affect on results.  
   (sfcphys.F)

 - A potential problem writing GrADS descriptor files has been fixed. (The 
   problem only occurred when certain descriptor files had no content, but 
   the code was trying to write to them anyway.)  
   Thanks to Casey Davenport of University of North Carolina at Charlotte.
   (writeout.F)

 - A problem with netcdf-format parcel output files ("pdata files") was fixed.
   When "output_path" was modified in the namelist (and thus output files are 
   not written in the same place as cm1.exe) the parcel files was not written 
   in the proper location.  Now, all netcdf-format files should be written 
   in the directory specified by "output_path".
   Thanks to Stacey Hitchcock of Colorado State University. 
   (writeout_nc.F)

 - A problem with netcdf-format restart files was fixed.  When the namelist 
   variable "restart_file_diags" was set to .true., then attempts to write 
   restart files would fail.  This problem has been fixed.  
   Thanks to Bruno Melli of Colorado State University. 
   (writeout_nc.F)


   -------------------
    cm1r19.6:

 - Updated the surface layer schemes from the WRF model (sfcmodel=2,3).  They
   are now the same as that in WRF4.0.
   (sfclay.F, sfclayrev.F)

 - Updated the Thompson microphysics scheme (ptype=3).  It is now the same as 
   the code in WRF4.0.
   (thompson.F)

 - Updated the NSSL microphysics code.  Thanks to Ted Mansell (NOAA/NSSL).
   (module_mp_nssl_2mom.F)

 - Fixed a bug with iinit=7 (tropical cyclone initialization) wherein the 
   base-state wind profile was ignored. 
   (init3d.F)

 - Fixed some minor bugs with the moving-domain option (imove=1).
   (param.F, solve.F, parcel.F, diff2.F, turb.F)

 - For imove=1, some descriptors in output files have been modified to 
   clarify whether the variable is grid-relative or ground-relative. 
   (writeout.F, statpack.F, azimavg.F, turbdiag.F)

 - Modified the lateral Rayleigh damping scheme (hrdamp=1) so that it is 
   only applied to vertical velocity. 
   (param.F)

 - Fixed a very minor bug when using the YSU PBL scheme and dissipative
   heating. 
   (turb.F)

 - Modified the code to estimate PBL depth (for diagnostic purposes only) 
   to be very similar to that in the YSU scheme.  Reduces PBL depths by 
   a factor of 2-3. 
   (sfcphys.F)

 - Modified calculations of domain-average profiles (u,v,t,q) to use 
   grid-area-weighted averages instead of simple arithmetic averages; this
   modification is needed to account for horizontal grid stretching in CM1
   (little-to-no change in results if horiz grid stretching is not used). 
   (testcase_simple_phys.F)

 - Several changes were made to the azimuthal averaging code:
     - Grid-area-weighted averages are now used instead of simple arithmetic 
       averages to account for horizontal grid stretching in CM1.
     - A new two-step methodology is used to determine the center of a storm;
       the first pass locates the location of minimum surface pressure 
       perturbation; the second step is the same as before (ie, finds the 
       point that yields the maximum possible azimuthally averaged tangential
       velocity).  This code was needed to account for very fast moving storms
       (because the old method used the last known centerpoint as a first 
       guess). 
     - The code was modified to account for cases when the storm is near a 
       lateral boundary. 
     - Wind speeds at z=10m have been added as output variables.
     - PBL depth has been added as an output variable. 
     - Radiative tendencies have been added as output variables. 
     - Eddy diffusivities from the YSU PBL scheme have been added as output 
       variables.
   (azimavg.F)

 - Fixed a bug with the calculation of resolved TKE tendency terms in the 
   turbulence diagnostic code. 
   (turbdiag.F)


   -------------------
    cm1r19.7:

 - Several technical problems with the parcel option (iprcl=1) when using 
   terrain (terrain_flag=.true.) have been fixed in this version.  The code 
   now parallelizes correctly, and can be used with restarts.  Thanks to 
   Dan Kirshbaum (McGill Univ) for identifying and fixing some of these 
   problems. 
   (parcel.F, init3d.F)

 - Documentation for the output_pdcomp option has been added to README.namelist. 
   (README.namelist)

 - Updated the variables in the tropical cyclone initialization scheme 
   (iinit=7).  Those variables specific to the Rotunno-Emanuel 1987 vortex 
   now have variable names ending in "_re87". 
   (init3d.F)

 - Updated the Thompson microphysics scheme (ptype=3).  It is now the same as 
   the code in WRF4.0.1.
   (thompson.F)

 - Fixed a very minor problem with the apmasscon=1 option to ensure 
   bit-identical parallelization with MPI. 
   (solve.F)


   -------------------
    cm1r19.8:

 - Modified MPI communications so that CM1 will work with default software
   on NCAR's Cheyenne supercomputer.  (Does not change results or performance.) 
   (various files)

 - Fixed error with surface flux in turbdiag output. 
   (turbdiag.F)

 - Fixed a minor bug with the NSSL microphysics schemes that was causing 
   slightly different results when output frequency was changed.  (Thanks to 
   Ted Mansell of NOAA/NSSL.)
   (module_mp_nssl_2mom.F)

 - Added a check at startup to ensure that all grid points (in all three 
   dimensions) have grid spacing > 0.  
   (param.F)

 - Modified the method to extrapolate velocity near the surface when isnd = 7. 
   (Thanks to Glen Romine, NCAR/MMM, for noting potential problems with the 
    old method.) 
   (base.F)


   -------------------
    cm1r19.9:

 - Fixed a bug in the 9th-order WENO advection code.  Thanks to Jerry Straka
   for pointing out this bug.  
   (adv_routines.F)

 - Changed the implicit solver for turbulence tendencies (doimpl=.true.) from
   Crank-Nicholson (vialpha = 0.5) to Euler forward (vialpha = 1.0).  This 
   change helps maintain stability for even larger time steps and/or smaller
   vertical grid spacing. 
   (constants.F)

 - Fixed some memory problems with writing 2d/3d output; only affected very 
   large simulations.
   (writeout.F)

 - Fixed several minor problems with netcdf-format output.  Thanks to Kamal 
   Kant Chandrakar for pointing out these problems. 
   (writeout_nc.F)

 - Increased the cap on the number of small (acoustic) time steps from 48 
   to 96.  This change allows for large advective timesteps for simulations 
   with weak flows (ie, a few m/s). 
   (misclibs.F)

 - Fixed a bug with lspgrad=2 and imove=1.  
   (base.F)

 - Updated the Thompson microphysics scheme (ptype=3).  It is now the same as 
   the code in WRF4.1.3
   (thompson.F)


   -------------------
    cm1r19.10:

 - Fixed problems with the mpi_wait command with some implementations of 
   MPI (eg, openmpi, impi) that were introduced in cm1r19.8.
   (comm.F, writeout.F, restart.F, hifrq.F)

 - Made some minor changes to allow for longer and more-general values 
   of outout_path and output_basename. 
   (writeout.F, writeout_nc.F, statpack.F, parcel.F) 

 - Fixed a quirky problem with restart frequencies.  (I think)
   (cm1.F)