Output Files

The Tiger-HLM Routing module writes its simulation results as NetCDF files. These outputs are generated automatically at the end of each simulated time chunk. The output system is fully configurable and supports multiple file types depending on the user’s analysis needs.

Output Configuration

All output settings are controlled through the configuration file:

output:
  output_path: "./data/Stony_Brook/outputs/"  # Directory where results are stored
  output_file: "dense.nc"                     # Full dense output file (time × system × state)
  final_output_file: "final.nc"               # Final states for each system
  runoff_output_file: "runoff.nc"             # Optional: only surface and total runoff
  states: [0,1,2,3,4,5,6,7,8]                 # State variables to include

Enabling and Disabling Outputs

Each output file can be toggled individually:

• To enable an output, assign it a valid filename (e.g., "dense.nc").
• To disable an output, set it to an empty string ("").

Example:

output_file: ""             # disables dense output
final_output_file: "final.nc"
runoff_output_file: ""      # disables runoff-only output

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Output Types

The module supports three distinct output types, each with its own purpose and file structure.

1. Dense Output File

Enable/Disable: Controlled by output_file Filename Pattern:

<output_path>/dense_<startDate>_<endDate>.nc

Contents: A 3D array [system, time, variable] storing all state variables.

Time Reference: Time is stored in minutes since the start of the chunk (units: minutes since YYYY-MM-DDTHH:MM:SSZ).

Purpose: Provides full timeseries of internal model states.

The states included correspond to the indices defined in output.states. For Model204, these typically include:

STATE_SNOW, STATE_STATIC, STATE_SURFACE, STATE_GRAV, STATE_AQUIFER, 
STATE_TEMP_AIR, STATE_TEMP_SOIL, STATE_SURF_RUNOFF, STATE_TOTAL_RUNOFF

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2. Final State File

Enable/Disable: Controlled by final_output_file Filename Pattern:

<output_path>/final_<startDate>_<endDate>.nc

Contents: A 2D array [system, variable] storing the final state of each link for the simulation chunk.

Purpose: Captures end-of-run conditions or restart states.

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3. Runoff Output File

Enable/Disable: Controlled by runoff_output_file Filename Pattern:

<output_path>/runoff_<startDate>_<endDate>.nc

Contents: A 2D array [system, time] storing only:

• surface_runoff
• total_runoff

Purpose: Stores only runoff outputs, which is used by the Tiger-HLM Routing module to generate streamflow hydrographs.

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Additional Details

Time Chunks

Outputs are written per processed time chunk. Each filename includes the simulation start and end date of that chunk.

MPI Runs

When running under MPI, each worker rank writes outputs for its assigned set of streams.