From b0a3bd7b61da14871211ea7c554879993e333ba7 Mon Sep 17 00:00:00 2001 From: Ann Almgren Date: Wed, 20 Nov 2024 11:18:13 -0800 Subject: [PATCH] update description of initialization (#1960) --- Docs/sphinx_doc/Inputs.rst | 38 +++++++++++------------ Docs/sphinx_doc/theory/Initialization.rst | 13 +++++--- 2 files changed, 27 insertions(+), 24 deletions(-) diff --git a/Docs/sphinx_doc/Inputs.rst b/Docs/sphinx_doc/Inputs.rst index 03e310e69..93172351f 100644 --- a/Docs/sphinx_doc/Inputs.rst +++ b/Docs/sphinx_doc/Inputs.rst @@ -1153,21 +1153,19 @@ with an ``erf.abl_geo_wind_table``. Initialization ============== -ERF can be initialized in different ways. These are listed below: - -- Custom initialization: - Several problems under **Exec** are initialized in a custom manner. The state and velocity components are specific to the problem. These problems are meant for demonstration and do not include any terrain or map scale factors. -- Initialization using a NetCDF file: - Problems in ERF can be initialized using a NetCDF file containing the mesoscale data. -The state and velocity components of the ERF domain are ingested from the mesoscale data. -This is a more realistic problem with real atmospheric data used for initialization. -The typical filename used for initialization is ``wrfinput_d01``, which is the outcome of running ``ideal.exe`` or ``real.exe`` of the WPS/WRF system. -These problems are run with both terrain and map scale factors. -- Initialization using an ``input_sounding`` file: - Problems in ERF can be initialized using an ``input_sounding`` file containing the vertical profile. -This file has the same format as used by ``ideal.exe`` executable in WRF. -Using this option for initialization, running ``ideal.exe`` and reading from the resulting ``wrfinput_d01`` file are not needed. -This option is used for initializing ERF domain to a horizontally homogeneous mesoscale state and does not include terrain or map scale factors. +The initialization in ERF has two steps: creation of the background state and creation of initial perturbations from the background state. + +The background initial data can be read from WPS-generated or metgrid files, reconstructed from 1-d input sounding data, +or specified by the user. Problem-specific perturbational quantities, specified separately by the user, are added to the background state. +When a hydrostatic background state must be defined at initialization, +we use a Newton-Raphson approach to solving the non-linear root finding problem that stems from requiring that the density, +pressure and potential temperature satisfy both the hydrostatic balance and the equation of state. +This is needed when ``init_type == Ideal`` but ``init_sounding_ideal`` is false. +Users have the option to define a dry or moist background state. + +The initialization strategy is determined at runtime by ``init_type``, which has six possible values. + +For more details on the hydrostatic initialization, see the ref:`Initialization section`. In addition, there is a run-time option to project the initial velocity field to make it divergence-free. @@ -1178,10 +1176,12 @@ List of Parameters | Parameter | Definition | Acceptable | Default | | | | Values | | +==================================+===================+====================+=======================+ -| **erf.init_type** | Initialization | “custom”, | “*custom*” | -| | type | “ideal”, | | -| | | "real", | | -| | |"input_sounding" | | +| **erf.init_type** | Initialization | "None", | "None" | +| | type | "Ideal", | | +| | | "Real", | | +| | | "Input_Sounding" | | +| | | "Metgrid" | | +| | | "Uniform" | | +----------------------------------+-------------------+--------------------+-----------------------+ | **erf.input_sounding_file** | Path to WRF-style | String | "input_sounding" | | | input sounding | | | diff --git a/Docs/sphinx_doc/theory/Initialization.rst b/Docs/sphinx_doc/theory/Initialization.rst index 10a7e1a50..68cc64af6 100644 --- a/Docs/sphinx_doc/theory/Initialization.rst +++ b/Docs/sphinx_doc/theory/Initialization.rst @@ -10,11 +10,14 @@ Initialization ================== -To initialize a background (base) state for a simulation with a hydrostatic atmosphere, the hydrostatic equation balancing the pressure gradient -and gravity must be satisfied. This section details the procedure for the initialization of the background state. The procedure is similar for the -cases with and without moisture, the only difference being that the density for the cases with moisture has to be the total density -:math:`\rho = \rho_d(1 + q_t)`, where :math:`\rho_d` is the dry density, and :math:`q_t` is the total mass mixing ratio -- water vapor and liquid water, instead -of the dry density :math:`\rho_d` for cases without moisture. +The initialization in ERF has two steps: creation of the background state and creation of initial perturbations from the background state. + +The background initial data can be read from WPS-generated or metgrid files, reconstructed from 1-d input sounding data, +specified by the user, or determined by the procedure below. Here we describe how ERF initializes base state values of density +and potential temperature such that the density, pressure and potential temperature satisfy both the hydrostatic balance and the equation of state. +Users have the option to define a dry or moist background state. + +This option is used when ``init_type == Ideal`` but ``init_sounding_ideal`` is false. Computation of the dry density -------------------------------