jgfs_marine_anl_init.ecf (GFS v17)

Branch / tenant: dev/gfs.v17 (gw_v17) Path: ecf/scripts/gfs/analysis/marine/jgfs_marine_anal_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_anl_init.ecf is the NCO production ecFlow task that initializes the marine (ocean + ice) data assimilation for the GFS cycle. It stages background fields, observation data, and B-matrix (background error covariance) inputs needed by the subsequent marine analysis variational solver. It calls JGLOBAL_MARINE_ANALYSIS_INITIALIZE, which drives exglobal_marine_analysis_initialize.py.

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1. The script itself

Section	Detail
PBS resources	1 node, 128 cpus, 24 GB, 10-min wall, shared
Modules	load_modules.sh ufsda (JEDI/SOCA data assimilation stack)
J-Job	JGLOBAL_MARINE_ANALYSIS_INITIALIZE
Rocoto breadcrumb	marineanlinit.sh

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2. Execution chain

jgfs_marine_anal_init.ecf
  +-- JGLOBAL_MARINE_ANALYSIS_INITIALIZE
       +-- exglobal_marine_analysis_initialize.py (Python/pygfs)
            +-- Stages ocean/ice backgrounds from previous GDAS cycle
            +-- Links observation data
            +-- Prepares B-matrix inputs

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3. Key environment variables

Variable	Meaning
COMIN_OBS	Observation input directory
COMIN_OCEAN_HISTORY_PREV	Previous cycle ocean history (background)
COMIN_ICE_HISTORY_PREV	Previous cycle ice history
COMIN_ICE_RESTART_PREV	Previous cycle ice restart
COMIN_OCEAN_BMATRIX	Ocean B-matrix directory
COMIN_ICE_BMATRIX	Ice B-matrix directory
DATAjob / DATAens / DATA	Shared working directories for marine analysis suite

Configuration

Sources jjob_header.sh -e "marineanlinit" -c "base marineanl marineanlinit".

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4. v17-specific notes

• Python-based driver (exglobal_marine_analysis_initialize.py) using pygfs.
• JEDI/SOCA DA stack: loads ufsda modules (SOCA, IODA, OOPS, UFO).
• Shared DATA directory: uses DATAjob shared across the marine analysis family (anl_init, bmat, anlvar, anlfinal, anlchkpt).
• 10-min walltime — lightweight staging/initialization.
• Part of the marine DA chain: anl_init -> bmat -> anlvar -> anlfinal -> anlchkpt.

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5. Change-impact snapshot

Symbol	Risk	Notes
JGLOBAL_MARINE_ANALYSIS_INITIALIZE	MEDIUM	Upstream of entire marine DA chain

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Sources

• On-disk v17 worktree: ecf/scripts/gfs/analysis/marine/jgfs_marine_anal_init.ecf, dev/jobs/JGLOBAL_MARINE_ANALYSIS_INITIALIZE.
• MCP (tenant gw_v17): on-disk analysis.