Run2 glm config

Advanced GLM Configuration

The General Lake Model (GLM) performance depends on several key parameters that govern energy balance and mixing.

Calibration Parameters and Effects

• Kw (Light Extinction): Controls how deep light penetrates. Higher Kw keeps deep layers cooler and surface layers warmer. Range: [0.1, 0.5].
• wind_factor: Scales input wind speed. Affects surface mixing and latent/sensible heat fluxes. Range: [0.7, 1.3].
• lw_factor: Scales incoming longwave radiation. Affects the overall heat budget. Range: [0.7, 1.3].
• ch (Sensible Heat Transfer): Bulk coefficient for sensible heat flux. Affects surface temperature. Range: [0.0005, 0.002].
• coef_mix_hyp: Controls mixing below the thermocline. Lower values reduce heating of the hypolimnion. Range: [0.3, 0.7].

Configuration Workflow

1. Baseline Run: Start with default parameters.
2. Energy Balance: Adjust lw_factor and ch to align the overall temperature magnitude.
3. Stratification: Adjust Kw and wind_factor to match the thermocline depth and surface temperatures.
4. Deep Mixing: Adjust coef_mix_hyp to match deep water temperatures during summer.

Example sed command for precise replacement:

sed -i 's/\bKw\s*=\s*[0-9.e+-]*/Kw = 0.4/' glm3.nml

Or use Python regex for more complex cases.