PyREC scaffolding (from YREC development, 7be4133)/ wczimp.fGlossary

wczimp.f

159 lines · 1 definitions · on GitHub (7be4133)

Python version: wczimp.py, 117 lines, on the right (switch to Python above the code).

Variables on this page (5)

cln, impjmod, json, lsolid, walpcz

Purpose

WCZIMP sets the rotation of a convection zone (shells ISTART–IEND) at fixed total angular momentum, as wcz.f (removed since rp_1) did, and adds options to impose a rotation profile on the radiative interior below the surface convection zone (JNT, 2015/05/14, copied into this code 2025/09/03–04). IMPJMOD ("impose J model," PARMIN's comment) chooses: 0, no effect; 1, solid-body rotation; 2, a solid-body core decoupled from the surface convection zone; 3, a solid-body core coupled to it.

The original date is 2015/05/14. The header says "copy of 2025/05/14" (line 40↗), but the later comments of the same change say "COPY OF 2015/05/14" (line 52↗) and "REPLICATING 2015/05/14" (line 77↗), and PARMIN says "JNT 05/15" (parmin.f, line 273↗), so the header's 2025 is a typo.

How it fits

  • Who calls it: GETROT and GETW (in place of WCZ since 09/25).
  • What it calls: SOLID, for the zone, single shells, or the interior.
  • Inputs and outputs: the arguments, as in solid.f: HJM, OMEGA, HI, QIW, ETA2, R0 are updated.
  • Modules: NMLPAR_MOD (the namelist parameters LSOLID, IMPJMOD and WALPCZ, read by PARMIN; formerly the COMMON blocks SBROT and ROT), CONSTANTS_MOD (CLN; formerly CONST1) and DIMENSIONS_MOD (JSON).

The method

With $m_j$ = HS2, $j_j$ = HJM, $I_j$ = HI, $\alpha$ = WALPCZ, $r_j = 10^{\texttt{HR}(j)}$:

  • Solid body for the zone if $\alpha \ge 0$, LSOLID, IMPJMOD = 1, or the zone is not the surface one (IEND < M). Since this test comes first, IMPJMOD = 2 and 3 take effect only with $\alpha < 0$; with the default WALPCZ = 0 they act as solid body (line 48↗).

  • IMPJMOD = 2: the zone follows $\Omega_j = \Omega_0 r_j^{\alpha}$ with $\Omega_0 = \sum_\mathrm{cz} m_j j_j / \sum_\mathrm{cz} r_j^{\alpha} I_j$; the interior (shells 1 to ISTART-1) is then made a solid body on its own, keeping its own angular momentum.

  • IMPJMOD = 3: the interior and the zone share one angular momentum budget; the interior rotates at the rate of the zone's base: $$\Omega_0 = \frac{\sum_{j \le N} m_j j_j}{r_\mathrm{s}^{\alpha}\sum_{j \le \mathrm{s}} I_j + \sum_{\mathrm{s} < j \le N} r_j^{\alpha} I_j},$$ with s = ISTART and $N$ = IEND; then $\Omega_j = \Omega_0 r_j^{\alpha}$ in the zone, $\Omega_j = \Omega_\mathrm{s}$ below it (lines 80–111↗).

  • Constant specific angular momentum if $\alpha \le -2$ (and IMPJMOD = 0), as in WCZ.

  • Otherwise the power law for the zone alone, as in WCZ. After each assignment, SOLID is called on single shells to make $\Omega$, $I$ and $j$ consistent.

From YREC's documentation

Physics Options: IMPJMOD sets the global coupling of angular momentum (0 no effect, 1 solid body everywhere, 2 solid-body core with a decoupled convection zone, 3 solid-body core coupled at the zone's base), and WALPCZ the profile in the convection zone, $\Omega \propto r^{\mathrm{WALPCZ}}$ (0 solid body, −2 uniform specific angular momentum).

Definitions

subroutineWCZIMP

lines 2–159 · GitHub

Rotation of a convection zone at fixed angular momentum (solid body, constant $j$, $\Omega \propto r^{\alpha}$), with options to impose solid-body rotation on the interior, decoupled from or coupled to the surface zone (IMPJMOD).

Uses modules CONSTANTS_MOD, DIMENSIONS_MOD, NMLPAR_MOD

Called by GETROT ×2, GETW ×2

Flowchart of its calls, in order (7)
SOLID50
for J = ISTART,IEND (DO 31), lines 65–72
SOLID70
if (ISTART.GT.1), lines 73–76
SOLID74
for J = ISTART,IEND (DO 34), lines 96–103
SOLID101
if (ISTART.GT.1), lines 104–111
SOLID109
for J = ISTART,IEND (DO 40), lines 126–133
SOLID131
for J = ISTART,IEND (DO 60), lines 149–156
SOLID154

Change log

The changes since rp_1

Changed since rp_1. The solid-body test is $\alpha \ge 0$ again (GT reverted to GE, JVS 2026/02/13), as in WCZ, which settles the former question 4 ($\alpha = 0$); declarations: COMMON blocks to modules, IMPLICIT NONE.