WRF Version 4.0.2 WRF Model Version 4.0.2: UPDATES The WRF model has been updated to Version 4.0.2 on November 9, 2018. The WRF Preprocessing System (WPS) has also been updated to Version 4.0.2. Acknowledgements: We would like to thank Tanya Smirnova (NOAA), Alexander Davies (US Naval Academy), Jeremy Silver (U. Melbourne), @sodoesburningbus, and Alexander Ukhov (KAUST) for their contributions to this release. This is a bug fix release. Following are fixes associated with this release. Dynamics: * Fix zero-valued d02 dry potential temperature perturbation from horizontal interpolation.This fix does not change the WRF model simulation results. However, if users grab the initial condition dry potential temperature perturbation field, "T" in the netcdf file, that value will be identically zero (the field is initialized within the solver routine for all subsequent time steps). Most WRF post-processors will assume that the field is a horizontally and vertically uniform dry potential temperature = 300 K, which would provide almost reasonable-looking values for temperature near the surface. After the first time step, the model results will be correct. This bug is in v4.0 and v4.0.1. Physics: Microphysics: * Morrison 2-moment scheme with consideration of CESM-NCSU RCP4.5 climatological aerosol A loop counter and an array index are changed from real to integer. This change makes the code able to compile on Cray. Explicitly name a small value as a PARAMETER so that the small value can be represented with single precision on Cray Cumulus parameterization: * A minor modification was made to the Grell 3 scheme to prevent random seed array bounds errors in the cup_forcing_ens_3d subroutine * Correct a few syntaxes in multi-scale Kain-Fritsch to make the code able to compile on Cray Land surface scheme: * Bug fix in RUC LSM for the computation of LAI for particular day when LAI parameter is read in from the VEGPARM.TBL. The bug makes the value of LAI smaller than it should be. * Bug fix for Noah LSM when rdalai2d is set to true. In areas where LAI is zero (and vegetation fraction isn’t), unrealistic sensible and latent heat fluxes are produced due to this bug, leading to model crash. PBL scheme: * The MYJ and QNSE PBLs use surface water vapor mixing ratio as low boundary condition for moisture and compute it from the latent heat flux, while other PBL schemes use directly latent heat flux as low boundary condition. Therefore, there is a special computation of latent heat flux inside RUC LSM to get correct surface Qv. In original code the check in the surface driver is made on the option of surface layer scheme, land not PBL scheme. Therefore, if MYJ PBL is not used together with MYJ surface layer scheme, there will be inaccuracy in low boundary condition for moisture. * A check was implemented to stop the real or wrf program if bl_mynn_edmf (which is set to 1 by default in the MYNN scheme) is being used in combination with either the ishallow or shcu_physics option turned on. A message informs the user that bl_mynn_edmf cannot be used with the other 2 options and the namelist must be modified. Ideal case: * The default value for vegfra in idealized cases was modified from a fraction to a percentage, consistent with the Noah LSM driver Data Assimilation: * Bug fix for WRFDA RANDOMCV when put_rand_seed=.false. and the compiler has a minimum size of random seed array larger than 10. * Fix WRFDA compilation when RTTOV-11 is built with HDF5-enabled. Chemistry: * Correct the chemical reaction rate constant for reaction: SO2 + OH -> SO4. This change applies only to the following chem_opt options: MOZART_KPP,MOZCART_KPP, T1_MOZCART_KPP,MOZART_MOSAIC_4BIN_KPP,MOZART_MOSAIC_4BIN_AQ_KPP. * Bug fix in optical_prep_gocart to better represent dust particles that have radii less than 0.46 microns. With this fix, the underestimation of AOD is overcome. * Bug fix for the contribution calculation of dust and sea salt bins into the MOZAIC bins. This fix leads to increased contribution of small dust and sea salt particles to AOD.