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    Horizontal advection options in MPAS

    Hi Ted Yes, the advection order inputs in the namelist have no effect. These were dropped in the solver during the optimization that occurred before the V5 release in 2017; we need to remove them and fix the documentation. The only options available are either 3rd or 4th order flux operators...
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    Instability from MYM_TURBULENCE2.5

    The last 4 lines are from the NOAH LSM, but I expect the LSM might not be happy with something coming from the MYNN scheme. I think it would be best for you to design a vertical grid with higher resolution where you want it to be while making sure the vertical grid spacing is not too small over...
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    Instability from MYM_TURBULENCE2.5

    I suspect that the problem is that the layers are getting much thinner in the boundary layer, and this is leading to the instability. There is not anything in the log file that directly points to the MYNN scheme. What information about the run points to MYNN problems? Also, are you running...
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    Dynamical core subroutines & time

    The subroutines that are part of the dynamical core are found in MPAS-Model/src/core_atmosphere/dynamics/mpas_atm_time_integration.F You can grep on "subroutine" and get a list of routines, many of which have timing output in the timing list. The routines that begin with capital letters are...
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    Running MPAS with CAM physics

    Hi, and sorry about this very late response. We have a working version of the MPAS dynamical core in the Community Atmosphere Model (CAM) that is the atmospheric component of the Community Earth System Model (CESM), and this is part of the System for Integrated Modeling of the Atmosphere (SIMA)...
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    dp / dzeta implementation in MPAS-A

    Hi Henry, Yes, this is an approximation, and we introduced it a few years ago (well after the main 2012 model description paper was published). The formulation of this term is described in the paper Skamarock, W. C., Ong, H., & Klemp, J. B. (2021). A Fully Compressible Nonhydrostatic...
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    Project Scientist: Earthworks Global Storm-Resolving Model Development

    The National Center for Atmospheric Research seeks a motivated Project Scientist to work with Andrew Gettelman and Bill Skamarock on a highly collaborative project with Colorado State University to build a new high-resolution coupled climate model called ‘Earthworks’. Earthworks will be a high...
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    Maximum updraft helicity in the Southern Hemisphere

    Hi Bruno, Yes, there is a northern hemisphere bias in the updraft helicity diagnostic! Additionally, we do observe anticyclonically rotating updrafts (uncommon but not rare) that this diagnostic would miss (e.g. splitting supercells). You have a couple of options to address this issue. (1)...
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    QUESTION: initial sounding files of WRF AWR v.4.0 test cases

    There is no test case using a GATE sounding. Single sounding initializations are used in a number of test cases where they are read from an editable ascii file, including the 2D squall-line test cases and the 3D supercell test case. You will need to edit (or generate in some fashion) the...
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    Namelist option: eddy viscosity for diffusion

    With the “2d_fixed” option, the horizontal and vertical eddy viscosities are set from the namelist.atmosphere parameters config_h_mom_eddy_visc2, config_v_mom_eddy_visc2, config_h_theta_eddy_visc2, and config_v_theta_eddy_visc2. These eddy viscosities are in units meters^2/second, “mom” in the...
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    Typo found in primitive equations WRF Technical notes V3

    There are errors in equation 2.39 in the online WRFV3 technical note. As you have noted, the right-hand-side forcing term should be F_V instead of F_U. Additionally, the map-scale factor ratio preceding the horizontal pressure gradient terms should be (m_y/m_x) instead of (m_x/m_y). The...
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    Perturbed initial conditions climate ensemble

    Perturbed initial conditions should be sufficient to create a probabilistic forecast. The CESM Large Ensemble was created in a similar way. They added noise (at the magnitude of round-off error) to temperature to create their 40-member ensemble I.C., see...
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