jgfs_marine_bmat_init ecf (v17) Analysis

jgfs_marine_bmat_init.ecf (GFS v17)

Branch / tenant: dev/gfs.v17 (gw_v17) Path: ecf/scripts/gfs/analysis/marine/jgfs_marine_bmat_init.ecf Analysis date: 2026-06-11 Method: AWS Bedrock AgentCore agentcore-mcp-rag MCP cross-checked against the on-disk v17 worktree.

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Summary

jgfs_marine_bmat_init.ecf is the NCO production ecFlow task that initializes the B-matrix computation for the marine data assimilation. It stages ensemble member data and prepares the working environment for the subsequent marine_bmat task. It calls JGLOBAL_MARINE_BMAT_INITIALIZE.

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1. The script itself

Section	Detail
PBS resources	1 node, 128 cpus, 24 GB, 20-min wall, shared
Modules	load_modules.sh ufsda (JEDI/SOCA stack)
J-Job	JGLOBAL_MARINE_BMAT_INITIALIZE
Rocoto breadcrumb	marinebmatinit.sh

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2. Execution chain

jgfs_marine_bmat_init.ecf
  +-- JGLOBAL_MARINE_BMAT_INITIALIZE
       +-- exglobal_marine_bmat_initialize.py (Python/pygfs)
            +-- Stages ensemble ocean/ice backgrounds
            +-- Prepares BUMP operator configuration

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3. v17-specific notes

• Lightweight setup for B-matrix computation (128 cpus but only 24 GB).
• Python-based driver using pygfs.
• JEDI/SOCA: loads ufsda modules.
• Part of marine DA chain: runs before marine_bmat, stages ensemble data.
• 20-min walltime — data staging operation.

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4. Change-impact snapshot

Symbol	Risk	Notes
JGLOBAL_MARINE_BMAT_INITIALIZE	MEDIUM	Upstream of B-matrix computation

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Sources

• On-disk v17 worktree: ecf/scripts/gfs/analysis/marine/jgfs_marine_bmat_init.ecf.
• MCP (tenant gw_v17): on-disk analysis.