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+# CalMIP Quick Start Guide
+
+## Summary
+
+This guide provides a quick reference for setting up CalMIP sites in ClimaLand.jl.
+
+## Required Files for Each Site
+
+| File Type | Location | Purpose |
+|-----------|----------|---------|
+| CSV forcing data | `data/callmip_sites/SITE-ID.csv` | Meteorological forcing |
+| Site configuration | `ext/fluxnet_simulations/SITE-ID.jl` | Site parameters |
+| Simulation runner | `experiments/integrated/fluxnet/callmip_SITE-ID.jl` | Run script |
+
+## Climate Variables Required (CSV columns)
+
+```
+TIMESTAMP_START,TIMESTAMP_END,TA_F,VPD_F,PA_F,P_F,WS_F,LW_IN_F,SW_IN_F,CO2_F_MDS
+```
+
+| Variable | Description | Units |
+|----------|-------------|-------|
+| `TIMESTAMP_START` | Start time (YYYYMMDDHHMM) | - |
+| `TIMESTAMP_END` | End time (YYYYMMDDHHMM) | - |
+| `TA_F` | Air temperature | °C |
+| `VPD_F` | Vapor pressure deficit | hPa |
+| `PA_F` | Air pressure | kPa |
+| `P_F` | Precipitation | mm |
+| `WS_F` | Wind speed | m/s |
+| `LW_IN_F` | Longwave radiation (down) | W/m² |
+| `SW_IN_F` | Shortwave radiation (down) | W/m² |
+| `CO2_F_MDS` | CO2 concentration | μmol/mol |
+
+## Quick Setup Steps
+
+### 0. Prepare CalMIP forcing data
+
+CalMIP CSV data files are NOT stored in git. Download from CalMIP and set up access:
+
+```bash
+# Option 1: Use environment variable (recommended)
+export CALLMIP_DATA_PATH="/path/to/your/callmip/data"
+mkdir -p $CALLMIP_DATA_PATH
+
+# Option 2: Use default local path
+mkdir -p ../callmip_data
+
+# Download and place your CSV files there
+```
+
+### 1. Update Artifacts.jl (if adding new sites)
+```julia
+# Add to: src/Artifacts.jl
+function callmip_data_path(site_ID; context = nothing)
+    @assert site_ID ∈ ("DK-Sor", "YOUR-SITE")  # ← Add here (only if adding new sites)
+    # ...
+end
+```
+
+### 2. Create site config file
+```bash
+# Copy template:
+cp ext/fluxnet_simulations/DK-Sor.jl ext/fluxnet_simulations/YOUR-SITE.jl
+# Edit YOUR-SITE.jl with your site's parameters
+```
+
+### 3. Update FluxnetSimulationsExt.jl
+```julia
+# Add to: ext/FluxnetSimulationsExt.jl
+include("fluxnet_simulations/YOUR-SITE.jl")  # ← Add here
+```
+
+### 4. Create simulation runner
+```bash
+# Copy template:
+cp experiments/integrated/fluxnet/callmip_dksor.jl \
+   experiments/integrated/fluxnet/callmip_yoursite.jl
+# Update site_ID and dates in callmip_yoursite.jl
+```
+
+### 5. Run simulation
+```bash
+# Make sure CALLMIP_DATA_PATH is set or data is in ../callmip_data/
+export CALLMIP_DATA_PATH="/path/to/callmip/data"
+
+julia --project=experiments experiments/integrated/fluxnet/callmip_yoursite.jl
+```
+
+## Site Information Needed
+
+For the site configuration file, you need:
+
+**Location:**
+- Latitude (decimal degrees)
+- Longitude (decimal degrees)
+- Time zone offset from UTC (hours)
+
+**Tower/Measurements:**
+- Measurement height (m)
+
+**Domain:**
+- Soil depth (m, typically 10m or deeper)
+- Vertical discretization (typically 20 elements)
+
+**Soil Properties:**
+- Porosity (ν)
+- Saturated hydraulic conductivity (K_sat)
+- Van Genuchten parameters (α, n)
+- Residual water content (θ_r)
+- Soil texture fractions
+
+**Vegetation:**
+- Canopy height (m)
+- Stem height (m)
+- Leaf height (m)
+- Rooting depth (m)
+- Plant functional type
+- Typical LAI range
+
+## Example Site: DK-Sor
+
+```julia
+# Site ID
+site_ID = "DK-Sor"
+
+# Location (Denmark)
+lat = 55.486°N
+long = 11.6446°E
+time_offset = +1  # CET (UTC+1)
+
+# Tower
+atmos_h = 57 m
+
+# Vegetation
+- Type: Deciduous Broadleaf Forest (Beech)
+- h_canopy = 30 m
+- h_stem = 25 m
+- h_leaf = 5 m
+- rooting_depth = 1.0 m
+```
+
+## CalMIP Data Sources
+
+1. **Protocol & Documentation:**
+   - https://github.com/callmip-org/Phase1
+
+2. **Forcing Data:**
+   - Model Evaluation Portal: https://modelevaluation.org
+   - CalMIP GitHub: https://github.com/callmip-org/Phase1/tree/main/Data
+
+3. **Observation Data (for calibration):**
+   - https://github.com/callmip-org/Phase1/tree/main/Data
+
+## File Naming Convention
+
+**Use hyphens in file names and site_ID strings:**
+```julia
+site_ID = "DK-Sor"  # ✓ Correct
+site_ID = "DK_Sor"  # ✗ Wrong
+```
+
+**Use underscores in Val types:**
+```julia
+Val(:DK_Sor)  # ✓ Correct
+Val(:DK-Sor)  # ✗ Wrong
+```
+
+## Typical Parameter Values
+
+### For Deciduous Broadleaf Forests
+
+```julia
+# Soil
+soil_ν = 0.45 - 0.55       # Porosity
+soil_K_sat = 1e-7 - 1e-6   # Hydraulic conductivity (m/s)
+soil_vg_n = 1.5 - 2.5      # Van Genuchten n
+soil_vg_α = 0.02 - 0.08    # Van Genuchten α (1/m)
+
+# Canopy
+Vcmax25 = 5e-5 - 8e-5      # Max carboxylation rate (mol/m²/s)
+g1 = 120 - 180             # Medlyn g1 parameter
+h_canopy = 15 - 35         # Canopy height (m)
+rooting_depth = 0.5 - 2.0  # Root depth (m)
+```
+
+### For Grasslands
+
+```julia
+# Soil (similar ranges)
+soil_ν = 0.40 - 0.50
+soil_K_sat = 5e-7 - 5e-6
+
+# Canopy
+Vcmax25 = 4e-5 - 7e-5
+g1 = 80 - 120
+h_canopy = 0.3 - 1.0       # Much shorter
+rooting_depth = 0.3 - 1.0  # Shallower
+```
+
+## Checking Your Setup
+
+Before running a full simulation, verify:
+
+```bash
+# 1. Check CSV file exists and has correct format
+head data/callmip_sites/YOUR-SITE.csv
+
+# 2. Check Julia can load the site
+julia --project=experiments -e '
+using ClimaLand
+site_ID = "YOUR-SITE"
+site_val = Symbol(replace(site_ID, "-" => "_"))
+println("Site: ", site_val)
+'
+
+# 3. Do a short test run (1 day)
+# Edit your runner script to set:
+# stop_date = start_date + Day(1)
+```
+
+## Common Errors
+
+### "Site not found in assertion"
+→ Add your site to `callmip_data_path` in `Artifacts.jl`
+
+### "Cannot read CSV file"
+→ Check path: `data/callmip_sites/YOUR-SITE.csv`
+
+### "Val type not defined"
+→ Include your site file in `FluxnetSimulationsExt.jl`
+
+### "Method not found for Val{:YOUR_SITE}"
+→ Use underscores in Val: `Val{:YOUR_SITE}` not `Val{:YOUR-SITE}`
+
+## Next Steps
+
+1. ✓ Complete setup (follow steps above)
+2. Run test simulation (1-7 days)
+3. Compare with observations
+4. Set up calibration workflow
+5. Follow CalMIP protocol for full runs
+
+## Additional Resources
+
+- Full documentation: `docs/CALLMIP_SETUP.md`
+- Example site: `ext/fluxnet_simulations/DK-Sor.jl`
+- Example runner: `experiments/integrated/fluxnet/callmip_dksor.jl`
+- CalMIP website: https://callmip-org.github.io
diff --git a/docs/CALLMIP_SETUP.md b/docs/CALLMIP_SETUP.md
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+# CalMIP Site Setup for ClimaLand.jl
+
+This directory contains the setup for running CalMIP (California Land Model Intercomparison Project) sites in ClimaLand.jl.
+
+## Overview
+
+The CalMIP project is a model intercomparison and calibration effort to improve land surface models. This setup provides a template for adding CalMIP sites to ClimaLand.
+
+**Current Status:** Template setup complete for DK-Sor (Denmark Sorø) test site from CalMIP Phase 1a.
+
+## CalMIP Resources
+
+- **GitHub Repository:** https://github.com/callmip-org/Phase1
+- **Website:** https://callmip-org.github.io
+- **Protocol:** [CalMIP Phase 1 Protocol v1.1](https://github.com/callmip-org/Phase1/blob/main/Protocol/CalLMIP_Phase1_Protocol_v1.1.pdf)
+
+## File Structure
+
+```
+ClimaLand.jl/
+├── src/
+│   └── Artifacts.jl                      # Updated with callmip_data_path function
+├── ext/
+│   ├── FluxnetSimulationsExt.jl         # Updated to include CalMIP sites
+│   └── fluxnet_simulations/
+│       └── DK-Sor.jl                    # Site-specific parameters
+└── experiments/
+    └── integrated/
+        └── fluxnet/
+            └── callmip_dksor.jl         # Simulation runner script
+```
+
+**Note on Data Storage:** CalMIP forcing data files (CSV) are NOT stored in the git repository. 
+Like other ClimaLand sites (US-MOz, US-Ha1, etc.), these should be managed through the 
+ClimaArtifacts system or stored locally. See "Data Location" section below.
+
+## Adding a New CalMIP Site
+
+Follow these steps to add a new CalMIP site:
+
+### 1. Prepare Climate Forcing Data (CSV file)
+
+**Important:** CalMIP forcing data files should NOT be committed to the git repository.
+
+Create a CSV file with the following columns and units:
+
+| Column Name      | Description                           | Units       |
+|-----------------|---------------------------------------|-------------|
+| TIMESTAMP_START | Start of averaging period (YYYYMMDDHHMM) | -      |
+| TIMESTAMP_END   | End of averaging period (YYYYMMDDHHMM)   | -      |
+| TA_F            | Air temperature                       | °C          |
+| VPD_F           | Vapor pressure deficit                | hPa         |
+| PA_F            | Air pressure                          | kPa         |
+| P_F             | Accumulated precipitation             | mm          |
+| WS_F            | Wind speed                            | m/s         |
+| LW_IN_F         | Downwelling longwave radiation        | W/m²        |
+| SW_IN_F         | Downwelling shortwave radiation       | W/m²        |
+| CO2_F_MDS       | CO2 concentration                     | μmol/mol    |
+
+#### Data Location Options:
+
+**Option 1: Environment Variable (Recommended for local testing)**
+```bash
+# Set the path to your CalMIP data directory
+export CALLMIP_DATA_PATH="/path/to/your/callmip/data"
+# Place your CSV files there: /path/to/your/callmip/data/DK-Sor.csv
+```
+
+**Option 2: Default Local Path**
+```bash
+# ClimaLand will look in: ../callmip_data/ (relative to ClimaLand.jl)
+mkdir ../callmip_data
+# Place your CSV files there
+```
+
+**Option 3: Add to ClimaArtifacts (Recommended for production)**
+For permanent integration, CalMIP data should be added to the ClimaArtifacts system
+(similar to how Fluxnet sites like US-MOz are stored). This requires:
+1. Uploading data to Caltech's artifact storage
+2. Updating the Artifacts.toml file
+3. Modifying `callmip_data_path()` in src/Artifacts.jl to use `@clima_artifact`
+
+**Where to get CalMIP data:**
+- CalMIP GitHub repository: https://github.com/callmip-org/Phase1/tree/main/Data
+- Model evaluation data portal: https://modelevaluation.org
+- Or obtain from Box link: https://caltech.box.com/shared/static/otrr2y0rgjct7hqhmq214nb8qjsvqj5p.gz
+
+Add your site to the `callmip_data_path` function in `src/Artifacts.jl`:
+
+```julia
+function callmip_data_path(site_ID; context = nothing)
+    @assert site_ID ∈ ("DK-Sor", "YOUR-SITE-ID")  # Add your site here
+    
+    climaland_dir = pkgdir(@__MODULE__)
+    data_path = joinpath(climaland_dir, "data", "callmip_sites", "$(site_ID).csv")
+    return data_path
+end
+```
+
+### 3. Create Site Information File
+
+Create a new file in `ext/fluxnet_simulations/` named after your site (e.g., `YOUR-SITE-ID.jl`).
+
+Use `ext/fluxnet_simulations/DK-Sor.jl` as a template. You need to define:
+
+```julia
+# Replace DK_Sor with your site ID (underscores instead of hyphens)
+function FluxnetSimulations.get_domain_info(FT, ::Val{:YOUR_SITE_ID}; ...)
+function FluxnetSimulations.get_location(FT, ::Val{:YOUR_SITE_ID}; ...)
+function FluxnetSimulations.get_fluxtower_height(FT, ::Val{:YOUR_SITE_ID}; ...)
+function FluxnetSimulations.get_parameters(FT, ::Val{:YOUR_SITE_ID}; ...)
+```
+
+**Key information needed:**
+- Latitude and longitude
+- Time zone offset from UTC
+- Tower/measurement height
+- Soil depth and properties
+- Vegetation type and parameters
+- Root depth and canopy height
+
+### 4. Update FluxnetSimulationsExt.jl
+
+Add your site file to the includes in `ext/FluxnetSimulationsExt.jl`:
+
+```julia
+include("fluxnet_simulations/YOUR-SITE-ID.jl")
+```
+
+### 5. Create Simulation Runner
+
+Create a simulation file in `experiments/integrated/fluxnet/` (e.g., `callmip_yoursite.jl`).
+
+Use `experiments/integrated/fluxnet/callmip_dksor.jl` as a template.
+
+**Key modifications needed:**
+- Update `site_ID = "YOUR-SITE-ID"`
+- Adjust simulation dates: `start_date` and `stop_date`
+- Modify output directory path if needed
+
+### 6. Run the Simulation
+
+First, ensure your CalMIP forcing data is accessible (via environment variable or local path):
+
+```bash
+# Option 1: Set environment variable
+export CALLMIP_DATA_PATH="/path/to/callmip/data"
+
+# Then run
+cd ClimaLand.jl
+julia --project=experiments experiments/integrated/fluxnet/callmip_yoursite.jl
+```
+
+## CalMIP-Specific Considerations
+
+### Output Variables
+
+CalMIP requires specific output variables. The current setup includes:
+
+**1D (surface) variables:**
+- GPP (Gross Primary Productivity)
+- NEE (Net Ecosystem Exchange) - calculated as ER - GPP
+- ET (Evapotranspiration)
+- Qle (Latent heat flux)
+- Qh (Sensible heat flux)
+- Rnet (Net radiation)
+
+**2D (profile) variables:**
+- Soil water content
+- Soil temperature
+
+Refer to the CalMIP protocol for the complete list of required outputs.
+
+### Calibration
+
+The CalMIP project focuses on model calibration. After setting up your site:
+
+1. Run the model with default/prior parameters
+2. Compare outputs with observations (from CalMIP data repository)
+3. Use calibration framework (see `experiments/calibration/`)
+4. Follow CalMIP protocol for calibration procedures
+
+### Data Sources
+
+- **Forcing data:** Available from CalMIP repository or modelevaluation.org
+- **Observation data:** Available from CalMIP Phase 1 data directory
+- **Site metadata:** See CalMIP protocol for soil texture, PFT cover, etc.
+
+## Example: DK-Sor Test Site
+
+The DK-Sor (Denmark Sorø) site is set up as an example:
+
+- **Location:** 55.486°N, 11.6446°E
+- **Vegetation:** Deciduous Broadleaf Forest (Beech)
+- **Purpose:** CalMIP Phase 1a test calibration
+
+**Files:**
+- Data: `data/callmip_sites/DK-Sor.csv` (example template only)
+- Site config: `ext/fluxnet_simulations/DK-Sor.jl`
+- Runner: `experiments/integrated/fluxnet/callmip_dksor.jl`
+
+## Data Format Notes
+
+### Forcing Data Requirements
+
+The CSV forcing data follows FLUXNET format conventions:
+- Timestamps in format YYYYMMDDHHMM
+- Half-hourly or hourly temporal resolution
+- Gap-filled meteorological data preferred
+- Quality flags can be included but are not required
+
+### Initial Conditions
+
+The simulation will use generic initial conditions unless you specify custom ones:
+- Soil moisture: From equilibrium or prior runs
+- Soil temperature: From equilibrium or prior runs
+- Canopy state: LAI from MODIS or prescribed
+
+## Troubleshooting
+
+### Common Issues
+
+1. **Missing data file:** Ensure your CSV file is in `data/callmip_sites/`
+2. **Site ID mismatch:** Use hyphens in site_ID string, underscores in Val{:SITE_ID}
+3. **Forcing data format:** Verify column names match exactly (case-sensitive)
+4. **Time zone issues:** Check time_offset sign (positive for east of UTC)
+
+### Data Processing
+
+If you need to convert CalMIP NetCDF data to CSV format:
+
+```julia
+# Example conversion script (adapt as needed)
+using NCDatasets
+using DataFrames, CSV
+
+# Load CalMIP NetCDF file
+ds = NCDataset("path/to/callmip_forcing.nc")
+
+# Extract variables and convert to DataFrame
+df = DataFrame(
+    TIMESTAMP_START = ds["time_start"][:],
+    TIMESTAMP_END = ds["time_end"][:],
+    TA_F = ds["Tair"][:],
+    # ... add other variables
+)
+
+# Save as CSV
+CSV.write("data/callmip_sites/YOUR-SITE-ID.csv", df)
+```
+
+## References
+
+- CalMIP Protocol: https://github.com/callmip-org/Phase1
+- ClimaLand Documentation: https://clima.github.io/ClimaLand.jl/dev/
+- FLUXNET Data Format: https://fluxnet.org/data/fluxnet2015-dataset/
+
+## Contact
+
+For CalMIP-specific questions, visit: https://callmip-org.github.io
+
+For ClimaLand integration issues, open an issue at: https://github.com/CliMA/ClimaLand.jl/issues
diff --git a/docs/CALLMIP_SUMMARY.md b/docs/CALLMIP_SUMMARY.md
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+# CalMIP Site Setup - Summary
+
+## What Was Created
+
+A complete template setup for running CalMIP (California Land Model Intercomparison Project) sites in ClimaLand.jl, using DK-Sor (Denmark Sorø) as an example test site.
+
+## Files Created/Modified
+
+### 1. Documentation
+- **`docs/CALLMIP_SETUP.md`** - Complete setup guide with detailed instructions
+- **`docs/CALLMIP_QUICKSTART.md`** - Quick reference guide for adding new sites
+- **`docs/CALLMIP_SUMMARY.md`** (this file) - Overview summary
+
+### 2. Data Files
+- **`data/callmip_sites/DK-Sor.csv`** - Example CSV template with forcing data format
+  - Contains 24 rows of example meteorological data
+  - Shows required column structure and units
+  - **Note:** Replace with actual CalMIP data before running real simulations
+
+### 3. Core Code Updates
+
+#### src/Artifacts.jl
+- Added `callmip_data_path()` function to handle CalMIP site data paths
+- Supports local data directory until CalMIP data is added to artifacts
+
+#### ext/fluxnet_simulations/DK-Sor.jl (NEW)
+- Complete site configuration for DK-Sor test site
+- Includes functions for:
+  - `get_domain_info()` - Soil depth and discretization
+  - `get_location()` - Lat/lon and time zone
+  - `get_fluxtower_height()` - Measurement height
+  - `get_parameters()` - Soil, canopy, and plant hydraulics parameters
+
+#### ext/FluxnetSimulationsExt.jl
+- Added include for DK-Sor.jl site configuration
+
+#### ext/fluxnet_simulations/data_processing.jl
+- Modified `read_fluxnet_data()` to handle both Fluxnet and CalMIP sites
+
+### 4. Simulation Runner
+- **`experiments/integrated/fluxnet/callmip_dksor.jl`** (NEW)
+  - Complete simulation setup for DK-Sor site
+  - Includes soil, canopy, and coupled model configuration
+  - Sets up diagnostics and output
+  - Based on ozark_pft.jl template
+
+## DK-Sor Site Specifications
+
+### Location
+- **Site:** Denmark Sorø
+- **Coordinates:** 55.486°N, 11.6446°E
+- **Time Zone:** UTC+1 (CET)
+- **Tower Height:** 57 m
+
+### Vegetation
+- **Type:** Deciduous Broadleaf Forest
+- **Dominant Species:** Beech (Fagus sylvatica)
+- **Canopy Height:** 30 m
+- **Stem Height:** 25 m
+- **Leaf Layer:** 5 m
+- **Rooting Depth:** 1.0 m
+
+### Soil Domain
+- **Depth:** 10 m (zmin = -10, zmax = 0)
+- **Elements:** 20
+- **Porosity:** 0.50
+- **Hydraulic Conductivity:** 5×10⁻⁷ m/s
+
+## Required CSV Data Format
+
+The forcing data CSV must contain these columns:
+
+| Column | Description | Units |
+|--------|-------------|-------|
+| TIMESTAMP_START | Start of period (YYYYMMDDHHMM) | - |
+| TIMESTAMP_END | End of period (YYYYMMDDHHMM) | - |
+| TA_F | Air temperature | °C |
+| VPD_F | Vapor pressure deficit | hPa |
+| PA_F | Air pressure | kPa |
+| P_F | Precipitation | mm |
+| WS_F | Wind speed | m/s |
+| LW_IN_F | Downwelling LW radiation | W/m² |
+| SW_IN_F | Downwelling SW radiation | W/m² |
+| CO2_F_MDS | CO2 concentration | μmol/mol |
+
+## How to Add a New CalMIP Site
+
+### Quick Steps:
+
+1. **Create forcing data CSV**
+   ```
+   data/callmip_sites/YOUR-SITE.csv
+   ```
+
+2. **Update Artifacts.jl**
+   - Add site to `callmip_data_path()` assertion
+
+3. **Create site configuration**
+   ```
+   ext/fluxnet_simulations/YOUR-SITE.jl
+   ```
+   (Copy and modify DK-Sor.jl)
+
+4. **Update FluxnetSimulationsExt.jl**
+   - Add include statement
+
+5. **Update data_processing.jl**
+   - Add site to `callmip_sites` tuple
+
+6. **Create simulation runner**
+   ```
+   experiments/integrated/fluxnet/callmip_yoursite.jl
+   ```
+   (Copy and modify callmip_dksor.jl)
+
+### Detailed Instructions
+See `docs/CALLMIP_SETUP.md` for complete step-by-step guide.
+
+## Where to Get CalMIP Data
+
+### Forcing Data
+1. **CalMIP GitHub Repository:**
+   - https://github.com/callmip-org/Phase1/tree/main/Data
+
+2. **Model Evaluation Portal:**
+   - https://modelevaluation.org
+
+3. **Box Link (example):**
+   - https://caltech.box.com/shared/static/otrr2y0rgjct7hqhmq214nb8qjsvqj5p.gz
+
+### Observation Data (for calibration)
+- Available in CalMIP Phase 1 Data directory
+- Includes NEE, Qle, Qh with uncertainties
+- See Phase 1a-test folder for DK-Sor example
+
+### Site Metadata
+- Refer to CalMIP Phase 1 Protocol (PDF)
+- Includes soil texture, PFT cover percentages
+- Available as NetCDF global attributes
+
+## CalMIP Output Variables
+
+The simulation is configured to output:
+
+**Surface (1D) variables:**
+- `gpp` - Gross Primary Productivity
+- `er` - Ecosystem Respiration  
+- `et` - Evapotranspiration
+- `shf` - Sensible Heat Flux
+- `lhf` - Latent Heat Flux
+- `rn` - Net Radiation
+- `swu`, `lwu` - Upwelling radiation
+- `gs` - Stomatal Conductance
+- `ct` - Canopy Temperature
+- Others...
+
+**Profile (2D) variables:**
+- `swc` - Soil Water Content (by depth)
+- `tsoil` - Soil Temperature (by depth)
+- `si` - Snow/Ice
+
+## Running the Example
+
+```bash
+# Navigate to ClimaLand directory
+cd ClimaLand.jl
+
+# Run the DK-Sor simulation
+julia --project=experiments experiments/integrated/fluxnet/callmip_dksor.jl
+```
+
+**Note:** The example CSV contains only template data. Replace it with actual CalMIP forcing data before running real simulations.
+
+## Output
+
+Results are saved to:
+```
+experiments/integrated/fluxnet/DK-Sor/callmip/out/
+```
+
+Includes:
+- Timeseries plots (GPP, fluxes, soil moisture, temperature)
+- Diurnal cycle analysis
+- Comparison with observations (if available)
+
+## Next Steps
+
+1. **Get Real Data:**
+   - Download actual DK-Sor forcing data from CalMIP repository
+   - Replace template CSV with real data
+
+2. **Test Run:**
+   - Run short simulation (1-7 days) to verify setup
+   - Check outputs and diagnostics
+
+3. **Full Simulation:**
+   - Extend to full simulation period (months to years)
+   - Generate outputs required by CalMIP protocol
+
+4. **Calibration:**
+   - Use ClimaLand calibration framework
+   - Follow CalMIP Phase 1 protocol for calibration targets
+   - See `experiments/calibration/` directory
+
+5. **Add More Sites:**
+   - Follow the same pattern for other CalMIP sites
+   - CalMIP Phase 1 includes multiple forest, grassland, and cropland sites
+
+## Important Notes
+
+### Site ID Naming Convention
+- Use **hyphens** in file names and strings: `"DK-Sor"`
+- Use **underscores** in Val types: `Val(:DK_Sor)`
+- This is handled automatically by `replace_hyphen()` function
+
+### Data Sources Must Match
+- Forcing data temporal resolution should match model timestep
+- Typically half-hourly (1800s) or hourly
+- Gap-fill missing data before running
+
+### Initial Conditions
+- Generic initial conditions are used by default
+- For better results, spin up the model for 1-2 years
+- Or use initial conditions from previous runs
+
+### Calibration Targets
+- CalMIP specifies which fluxes to calibrate against
+- Typically: NEE, Qle, Qh with uncertainties provided
+- See CalMIP protocol for full list
+
+## References
+
+### CalMIP Project
+- **Website:** https://callmip-org.github.io
+- **GitHub:** https://github.com/callmip-org/Phase1
+- **Protocol:** CalMIP Phase 1 Protocol v1.1 (PDF in repository)
+
+### ClimaLand
+- **Documentation:** https://clima.github.io/ClimaLand.jl/dev/
+- **GitHub:** https://github.com/CliMA/ClimaLand.jl
+- **Issues:** https://github.com/CliMA/ClimaLand.jl/issues
+
+### FLUXNET
+- **Data Format:** https://fluxnet.org/data/fluxnet2015-dataset/
+- Used as basis for CalMIP forcing data format
+
+## Troubleshooting
+
+### Common Issues
+
+**"Site not found" error:**
+- Ensure site is added to all necessary files (see checklist above)
+- Check spelling consistency (DK-Sor vs DK_Sor)
+
+**"Cannot find CSV file":**
+- Verify file path: `data/callmip_sites/SITE-ID.csv`
+- Check file permissions
+
+**"Method not found for Val":**
+- Site configuration file not included in FluxnetSimulationsExt.jl
+- Val type uses underscore, not hyphen
+
+**"Data format error":**
+- Verify CSV has exactly the required columns
+- Check for missing headers
+- Ensure numeric data is not quoted
+
+### Getting Help
+
+- **CalMIP questions:** Visit https://callmip-org.github.io
+- **ClimaLand questions:** Open issue at ClimaLand.jl GitHub
+- **Documentation:** Read `docs/CALLMIP_SETUP.md` for detailed guide
+
+## File Checklist
+
+When adding a new site, ensure you've created/modified:
+
+- [ ] CSV forcing data file
+- [ ] Site configuration (.jl file)
+- [ ] Artifacts.jl (add site to assertion)
+- [ ] FluxnetSimulationsExt.jl (include site file)
+- [ ] data_processing.jl (add to callmip_sites tuple)
+- [ ] Simulation runner script
+- [ ] Test with short simulation
+- [ ] Verify outputs
+
+## Example Site Comparison
+
+| Aspect | DK-Sor (CalMIP) | US-MOz (Fluxnet) |
+|--------|-----------------|------------------|
+| Location | Denmark | Missouri, USA |
+| Vegetation | Beech Forest | Oak Forest |
+| Canopy Height | 30 m | 18.5 m |
+| Time Zone | UTC+1 | UTC-6 |
+| Data Source | CalMIP | AmeriFlux |
+| Purpose | Calibration Test | Model Validation |
+
+Both use the same underlying ClimaLand model structure and follow similar setup procedures.
+
+## Version Information
+
+- **ClimaLand.jl:** Compatible with current main branch
+- **CalMIP Protocol:** Phase 1 Protocol v1.1
+- **Date Created:** February 2026
+- **Status:** Template setup complete, awaiting real forcing data
+
+---
+
+**For detailed instructions, see:** `docs/CALLMIP_SETUP.md`  
+**For quick reference, see:** `docs/CALLMIP_QUICKSTART.md`
diff --git a/experiments/integrated/fluxnet/CALLMIP_README.md b/experiments/integrated/fluxnet/CALLMIP_README.md
new file mode 100644
index 00000000000..7630ff02dd3
--- /dev/null
+++ b/experiments/integrated/fluxnet/CALLMIP_README.md
@@ -0,0 +1,219 @@
+# CalMIP DK-Sor Site Simulation Guide
+
+This directory contains the setup for running CalMIP (Calibration Land Model Intercomparison Project) simulations for the DK-Sor (Denmark Sorø) flux tower site in ClimaLand.jl.
+
+## Files Created
+
+### 1. Site Configuration
+- **Location**: `ext/fluxnet_simulations/DK-Sor.jl`
+- Contains site-specific parameters:
+  - Location: 55.486°N, 11.6446°E, UTC+1
+  - Vegetation: Deciduous Broadleaf Forest (Beech)
+  - Soil parameters: porosity, hydraulic conductivity, van Genuchten parameters
+  - Canopy parameters: height (30m), Vcmax25, stomatal conductance
+
+### 2. Simulation Runner
+- **File**: `experiments/integrated/fluxnet/callmip_dksor.jl`
+- Runs full year simulation (2008)
+- Timestep: 450 seconds (7.5 minutes)
+- Saves 16 diagnostic variables at half-hourly resolution
+
+### 3. Forcing Data
+- **Location**: `/net/sampo/data1/renatob/callmip_forcing/DK-Sor.csv`
+- **Source**: Converted from `DK-Sor_1997-2014_FLUXNET2015_Met.nc`
+- **Variables**: Air temperature, VPD, pressure, precipitation, wind, radiation, CO2
+- **Period**: 1997-2015 (315,552 half-hourly timesteps)
+- **Conversion Script**: `convert_netcdf_fast.py` (Python)
+
+### 4. Observation Data
+- **Location**: `/net/sampo/data1/renatob/DK-Sor_daily_aggregated_1997-2013_FLUXNET2015_Flux.nc`
+- **Variables**: LE (latent heat), H (sensible heat), NEE (net ecosystem exchange)
+- **Usage**: For model validation and comparison
+
+### 5. Analysis Tools
+
+#### Comparison Script
+- **File**: `compare_callmip_observations.py`
+- **Purpose**: Compare simulation outputs with flux observations
+- **Features**:
+  - Reads HDF5 simulation outputs
+  - Reads NetCDF flux observations
+  - Calculates statistics (RMSE, bias, correlation)
+  - Creates timeseries and scatter plots
+
+#### Monitoring Script
+- **File**: `monitor_callmip.sh`
+- **Purpose**: Monitor simulation progress
+- **Usage**: `./monitor_callmip.sh`
+
+## Running the Simulation
+
+### Quick Start
+```bash
+cd $HOME/ClimaLand.jl
+julia --project=. experiments/integrated/fluxnet/callmip_dksor.jl
+```
+
+### Background Run (for long simulations)
+```bash
+cd $HOME/ClimaLand.jl
+nohup julia --project=. experiments/integrated/fluxnet/callmip_dksor.jl > callmip_run.log 2>&1 &
+```
+
+### Monitor Progress
+```bash
+./experiments/integrated/fluxnet/monitor_callmip.sh
+# or
+tail -f callmip_run.log
+```
+
+## Output Structure
+
+### Simulation Outputs
+- **Directory**: `experiments/integrated/fluxnet/DK-Sor/callmip/out/`
+- **Format**: HDF5 files (one per diagnostic variable)
+- **Frequency**: Half-hourly (30-minute intervals)
+
+### Diagnostic Variables (16 total)
+Key outputs include:
+- `lhf.hdf5` - Latent heat flux (W/m²)
+- `shf.hdf5` - Sensible heat flux (W/m²)
+- `gpp.hdf5` - Gross primary production (μmol/m²/s)
+- `sw.hdf5` - Soil water content (m³/m³)
+- `st.hdf5` - Soil temperature (K)
+- Additional canopy and soil variables
+
+## Comparing with Observations
+
+Once the simulation completes, compare with observations:
+
+```bash
+python3 experiments/integrated/fluxnet/compare_callmip_observations.py \
+  --flux-file /net/sampo/data1/renatob/DK-Sor_daily_aggregated_1997-2013_FLUXNET2015_Flux.nc \
+  --output-dir experiments/integrated/fluxnet/DK-Sor/callmip/out/ \
+  --start-date 2008-01-01 \
+  --end-date 2009-01-01 \
+  --plot-dir experiments/integrated/fluxnet/DK-Sor/callmip/plots/
+```
+
+This will generate:
+- Timeseries comparison plots for LE, H, NEE
+- Scatter plots with statistics (RMSE, bias, R)
+- Console output with quantitative metrics
+
+## Data Processing Pipeline
+
+### NetCDF → CSV Conversion
+The forcing data was converted using:
+```bash
+python3 experiments/integrated/fluxnet/convert_netcdf_fast.py \
+  /net/sampo/data1/renatob/DK-Sor_1997-2014_FLUXNET2015_Met.nc \
+  /net/sampo/data1/renatob/callmip_forcing/DK-Sor.csv
+```
+
+### Data Flow
+```
+NetCDF Forcing → CSV → ClimaLand Simulation → HDF5 Outputs
+                                                    ↓
+NetCDF Observations ← ← ← ← ← ← Comparison Script
+```
+
+## Key Modifications to ClimaLand
+
+1. **Artifacts.jl**
+   - Added `callmip_data_path()` function
+   - Points to `/net/sampo/data1/renatob/callmip_forcing/`
+
+2. **data_processing.jl**
+   - Updated `read_fluxnet_data()` to recognize CalMIP sites
+   - Checks for "DK-Sor" and routes to CalMIP data path
+
+3. **initial_conditions.jl**
+   - Updated `set_fluxnet_ic!()` to handle CalMIP sites
+   - Routes CalMIP sites to appropriate data path
+
+## Simulation Details
+
+### Model Components
+- **Soil**: Energy-Hydrology model with biogeochemistry
+  - 20 layers, exponentially stretched
+  - Depth: 0 to -10m
+  - van Genuchten hydraulic model
+
+- **Canopy**: Coupled photosynthesis and plant hydraulics
+  - Two-stream radiative transfer
+  - Farquhar photosynthesis model
+  - Medlyn stomatal conductance
+  - Plant hydraulics with Weibull vulnerability curve
+
+- **CO2**: Soil CO2 production and transport
+
+### Timestepping
+- Integration: IMEX (Implicit-Explicit) scheme
+- Timestep: 450 seconds (7.5 minutes)
+- Adaptive stepping with Newton solver
+
+### Boundary Conditions
+- Top: Atmospheric forcing from CSV data
+- Bottom: Zero flux (deep drainage allowed through runoff)
+
+## Troubleshooting
+
+### Common Issues
+
+1. **Package not found errors**
+   - Solution: Use `--project=.` flag (not `--project=experiments`)
+   - Ensures proper package environment
+
+2. **Data path errors**
+   - Check that CSV file exists at: `/net/sampo/data1/renatob/callmip_forcing/DK-Sor.csv`
+   - Verify file permissions
+
+3. **Slow compilation**
+   - First run takes 2-5 minutes to compile
+   - Subsequent runs are much faster
+   - Use `--compile=min` to reduce compilation time
+
+4. **Memory issues**
+   - Year-long simulation uses ~1.5-2GB RAM
+   - Reduce diagnostic frequency if needed
+
+### Checking Simulation Status
+```bash
+# Check if running
+ps aux | grep "julia.*callmip_dksor"
+
+# Check progress
+tail -f callmip_run.log
+
+# Check output files
+ls -lh experiments/integrated/fluxnet/DK-Sor/callmip/out/
+```
+
+## Performance Expectations
+
+- **Compilation time**: 2-5 minutes (first run)
+- **Simulation time** (1 year, half-hourly output):
+  - Expected: 5-15 minutes on typical workstation
+  - Varies with CPU speed and available cores
+- **Output size**: ~100-500 MB total (all diagnostics)
+
+## Next Steps
+
+1. ✅ Run full year simulation (2008)
+2. ⏳ Wait for completion (~10-15 min)
+3. 📊 Compare with observations
+4. 📈 Generate validation plots
+5. 📝 Calculate performance metrics
+6. 🔄 Extend to multi-year runs if needed
+
+## References
+
+- CalMIP Protocol: https://github.com/callmip-org/Phase1
+- FLUXNET2015: https://fluxnet.org/
+- DK-Sor Site: Deciduous beech forest in Denmark
+- ClimaLand.jl: https://github.com/CliMA/ClimaLand.jl
+
+## Contact
+
+For issues or questions about this CalMIP setup, see the ClimaLand.jl repository or CalMIP protocol documentation.
diff --git a/experiments/integrated/fluxnet/callmip_dksor.jl b/experiments/integrated/fluxnet/callmip_dksor.jl
new file mode 100644
index 00000000000..4cfa1173718
--- /dev/null
+++ b/experiments/integrated/fluxnet/callmip_dksor.jl
@@ -0,0 +1,337 @@
+"""
+This experiment runs the DK-Sor (Denmark Sorø) CalMIP Phase 1a test site.
+
+The DK-Sor site is a deciduous broadleaf forest in Denmark, dominated by beech trees.
+This is the test calibration site for CalMIP Phase 1a.
+
+For more information about the CalMIP project and protocols:
+https://github.com/callmip-org/Phase1
+https://callmip-org.github.io
+
+Citation: CalMIP Phase 1 Protocol v1.1
+"""
+
+import ClimaLand
+import SciMLBase
+using ClimaCore
+import ClimaComms
+import ClimaParams as CP
+using Dates
+using Insolation
+
+using ClimaLand
+using ClimaLand.Domains: Column
+using ClimaLand.Soil
+using ClimaLand.Soil.Biogeochemistry
+using ClimaLand.Canopy
+using ClimaLand.Canopy.PlantHydraulics
+import ClimaLand.Simulations: LandSimulation, solve!
+import ClimaLand
+import ClimaLand.Parameters as LP
+using ClimaDiagnostics
+using ClimaUtilities
+
+using DelimitedFiles
+import ClimaLand.FluxnetSimulations as FluxnetSimulations
+# using CairoMakie, ClimaAnalysis, GeoMakie, Printf, StatsBase
+# import ClimaLand.LandSimVis as LandSimVis
+
+const FT = Float64
+toml_dict = LP.create_toml_dict(FT)
+climaland_dir = pkgdir(ClimaLand)
+
+# Site identification
+site_ID = "DK-Sor"
+site_ID_val = FluxnetSimulations.replace_hyphen(site_ID)
+
+# Get the default values for this site's domain, location, and parameters
+(; dz_tuple, nelements, zmin, zmax) =
+    FluxnetSimulations.get_domain_info(FT, Val(site_ID_val))
+(; time_offset, lat, long) =
+    FluxnetSimulations.get_location(FT, Val(site_ID_val))
+(; atmos_h) = FluxnetSimulations.get_fluxtower_height(FT, Val(site_ID_val))
+
+# Get site parameters
+(;
+    soil_ν,
+    soil_K_sat,
+    soil_S_s,
+    soil_vg_n,
+    soil_vg_α,
+    θ_r,
+    ν_ss_quartz,
+    ν_ss_om,
+    ν_ss_gravel,
+    z_0m_soil,
+    z_0b_soil,
+    soil_ϵ,
+    soil_α_PAR,
+    soil_α_NIR,
+    Ω,
+    χl,
+    α_PAR_leaf,
+    λ_γ_PAR,
+    τ_PAR_leaf,
+    α_NIR_leaf,
+    τ_NIR_leaf,
+    ϵ_canopy,
+    ac_canopy,
+    g1,
+    Drel,
+    g0,
+    Vcmax25,
+    SAI,
+    f_root_to_shoot,
+    K_sat_plant,
+    ψ63,
+    Weibull_param,
+    a,
+    conductivity_model,
+    retention_model,
+    plant_ν,
+    plant_S_s,
+    rooting_depth,
+    n_stem,
+    n_leaf,
+    h_leaf,
+    h_stem,
+    h_canopy,
+) = FluxnetSimulations.get_parameters(FT, Val(site_ID_val))
+
+compartment_midpoints =
+    n_stem > 0 ? [h_stem / 2, h_stem + h_leaf / 2] : [h_leaf / 2]
+compartment_surfaces = n_stem > 0 ? [zmax, h_stem, h_canopy] : [zmax, h_leaf]
+
+# Construct the ClimaLand domain to run the simulation on
+land_domain = Column(;
+    zlim = (zmin, zmax),
+    nelements = nelements,
+    dz_tuple = dz_tuple,
+    longlat = (long, lat),
+)
+canopy_domain = ClimaLand.Domains.obtain_surface_domain(land_domain)
+prognostic_land_components = (:canopy, :soil, :soilco2)
+
+# Set up the timestepping information for the simulation
+dt = Float64(450) # 7.5 minutes
+# Define simulation period - short 1-day test
+start_date = DateTime(2008, 1, 1)
+stop_date = DateTime(2009, 1, 1)  # Full year 2008
+
+# This reads in the data from the CalMIP site and creates
+# the atmospheric and radiative driver structs for the model.
+# CalMIP-format data for this site are handled via the shared
+# Fluxnet/CalMIP data-reading utilities used by `prescribed_forcing_fluxnet`.
+(; atmos, radiation) = FluxnetSimulations.prescribed_forcing_fluxnet(
+    site_ID,
+    lat,
+    long,
+    time_offset,
+    atmos_h,
+    start_date,
+    toml_dict,
+    FT;
+    split_precip = :callmip,
+)
+
+# Set up soil model
+soil_domain = land_domain
+soil_albedo = Soil.ConstantTwoBandSoilAlbedo{FT}(;
+    PAR_albedo = soil_α_PAR,
+    NIR_albedo = soil_α_NIR,
+)
+
+runoff = ClimaLand.Soil.Runoff.SurfaceRunoff()
+retention_parameters = (;
+    ν = soil_ν,
+    θ_r,
+    K_sat = soil_K_sat,
+    hydrology_cm = vanGenuchten{FT}(; α = soil_vg_α, n = soil_vg_n),
+)
+composition_parameters = (; ν_ss_om, ν_ss_quartz, ν_ss_gravel)
+soil_forcing = (; atmos, radiation)
+soil = Soil.EnergyHydrology{FT}(
+    soil_domain,
+    soil_forcing,
+    toml_dict;
+    prognostic_land_components,
+    additional_sources = (ClimaLand.RootExtraction{FT}(),),
+    albedo = soil_albedo,
+    runoff,
+    retention_parameters,
+    composition_parameters,
+    S_s = soil_S_s,
+    z_0m = z_0m_soil,
+    z_0b = z_0b_soil,
+    emissivity = soil_ϵ,
+)
+
+# Soil microbes model
+co2_prognostic_soil = Soil.Biogeochemistry.PrognosticMet(soil.parameters)
+drivers = Soil.Biogeochemistry.SoilDrivers(co2_prognostic_soil, atmos)
+soilco2 = Soil.Biogeochemistry.SoilCO2Model{FT}(soil_domain, drivers, toml_dict)
+
+# Set up canopy radiative transfer
+radiation_parameters = (;
+    Ω,
+    G_Function = CLMGFunction(χl),
+    α_PAR_leaf,
+    τ_PAR_leaf,
+    α_NIR_leaf,
+    τ_NIR_leaf,
+)
+radiative_transfer = Canopy.TwoStreamModel{FT}(
+    canopy_domain,
+    toml_dict;
+    radiation_parameters,
+    ϵ_canopy,
+)
+
+# Set up stomatal conductance
+conductance = Canopy.MedlynConductanceModel{FT}(canopy_domain, toml_dict; g1)
+
+# Set up photosynthesis
+photosynthesis_parameters = (; is_c3 = FT(1), Vcmax25)
+photosynthesis =
+    FarquharModel{FT}(canopy_domain, toml_dict; photosynthesis_parameters)
+
+# Set up plant hydraulics
+surface_space = land_domain.space.surface
+
+# Use prescribed LAI from MODIS data or constant LAI for testing
+LAI =
+    ClimaLand.Canopy.prescribed_lai_modis(surface_space, start_date, stop_date)
+# Get the maximum LAI at this site over the first year of the simulation
+maxLAI = FluxnetSimulations.get_maxLAI_at_site(start_date, lat, long)
+RAI = maxLAI * f_root_to_shoot
+
+hydraulics = Canopy.PlantHydraulicsModel{FT}(
+    canopy_domain,
+    toml_dict;
+    n_stem,
+    n_leaf,
+    h_stem,
+    h_leaf,
+    ν = plant_ν,
+    S_s = plant_S_s,
+    conductivity_model,
+    retention_model,
+)
+
+height = h_stem + h_leaf
+biomass =
+    Canopy.PrescribedBiomassModel{FT}(; LAI, SAI, RAI, rooting_depth, height)
+
+# Set up canopy energy model
+energy = Canopy.BigLeafEnergyModel{FT}(toml_dict; ac_canopy)
+
+ground = ClimaLand.PrognosticGroundConditions{FT}()
+canopy_forcing = (; atmos, radiation, ground)
+
+# Construct the canopy model
+canopy = Canopy.CanopyModel{FT}(
+    canopy_domain,
+    canopy_forcing,
+    LAI,
+    toml_dict;
+    prognostic_land_components,
+    radiative_transfer,
+    photosynthesis,
+    conductance,
+    hydraulics,
+    energy,
+    biomass,
+)
+
+# Integrated land model
+land = SoilCanopyModel{FT}(soilco2, soil, canopy)
+
+# Set initial conditions
+set_ic! = FluxnetSimulations.make_set_fluxnet_initial_conditions(
+    site_ID,
+    start_date,
+    time_offset,
+    land,
+)
+
+# Set up diagnostics
+# Define output directory for diagnostics
+outdir = joinpath(
+    pkgdir(ClimaLand),
+    "experiments/integrated/fluxnet/$(site_ID)/callmip/out",
+)
+mkpath(outdir)
+println("Creating NetCDF output writer for directory: ", outdir)
+
+# Use NetCDFWriter to save diagnostics to NetCDF files
+output_writer = ClimaDiagnostics.Writers.NetCDFWriter(
+    soil_domain.space.subsurface,
+    outdir;
+    start_date,
+)
+
+# CalMIP requires specific output variables - ensure these match protocol requirements
+short_names_1D = [
+    "sif",       # Solar-induced fluorescence
+    "ra",        # Autotrophic respiration
+    "gs",        # Stomatal conductance
+    "gpp",       # Gross primary productivity
+    "ct",        # Canopy temperature
+    "swu",       # Upwelling shortwave radiation
+    "lwu",       # Upwelling longwave radiation
+    "er",        # Ecosystem respiration
+    "et",        # Evapotranspiration
+    "msf",       # Moisture surface flux
+    "shf",       # Sensible heat flux
+    "lhf",       # Latent heat flux
+    "rn",        # Net radiation
+]
+short_names_2D = [
+    "swc",       # Soil water content
+    "tsoil",     # Soil temperature
+    "si",        # Snow/ice
+]
+output_vars = [short_names_1D..., short_names_2D...]
+
+diags = ClimaLand.default_diagnostics(
+    land,
+    start_date;
+    output_writer = output_writer,
+    output_vars,
+    reduction_period = :halfhourly,
+)
+
+# Run the simulation
+simulation = LandSimulation(
+    start_date,
+    stop_date,
+    dt,
+    land;
+    set_ic! = set_ic!,
+    updateat = Second(dt),
+    diagnostics = diags,
+)
+solve!(simulation)
+
+# Post-processing
+println("\nSimulation completed successfully!")
+println("Start date: ", start_date)
+println("Stop date: ", stop_date)
+println("Number of diagnostics: ", length(diags))
+
+# Close the output writers to flush diagnostics to files
+ClimaLand.Diagnostics.close_output_writers(diags)
+println("Output files written to: ", outdir)
+
+# List output files
+println("Output files:")
+for file in readdir(outdir; join = false)
+    filepath = joinpath(outdir, file)
+    if isfile(filepath)
+        filesize_mb = round(stat(filepath).size / 1024^2, digits = 2)
+        println("  $file ($(filesize_mb) MB)")
+    end
+end
+
+# TODO: Add visualization when CairoMakie is available
+# TODO: Add comparison with observation data from Flux NetCDF file
diff --git a/experiments/integrated/fluxnet/callmip_dksor_default.jl b/experiments/integrated/fluxnet/callmip_dksor_default.jl
new file mode 100644
index 00000000000..391959a7049
--- /dev/null
+++ b/experiments/integrated/fluxnet/callmip_dksor_default.jl
@@ -0,0 +1,176 @@
+# ── DK-Sor CalMIP Phase 1a: Default LandModel Configuration ──────────────────
+#
+# This script runs the DK-Sor (Denmark Sorø) CalMIP Phase 1a site using the
+# high-level LandModel constructor, which auto-configures all sub-models
+# (soil, canopy, snow, soilCO2) from toml/spatial defaults.
+#
+# Default sub-models:
+#   - Photosynthesis: FarquharModel
+#   - Conductance: MedlynConductanceModel
+#   - Radiative transfer: TwoStreamModel
+#   - Soil moisture stress: TuzetMoistureStressModel
+#   - Plant hydraulics: PlantHydraulicsModel
+#   - Energy: BigLeafEnergyModel
+#   - Snow: SnowModel (with default albedo)
+#
+# For more information about the CalMIP project:
+# https://github.com/callmip-org/Phase1
+# https://callmip-org.github.io
+
+# ── 1. Imports ────────────────────────────────────────────────────────────────
+import ClimaLand
+import SciMLBase
+using ClimaCore
+import ClimaComms
+import ClimaParams as CP
+using Dates
+using Insolation
+
+using ClimaLand
+using ClimaLand: LandModel
+using ClimaLand.Domains: Column
+using ClimaLand.Soil
+using ClimaLand.Soil.Biogeochemistry
+using ClimaLand.Canopy
+using ClimaLand.Canopy.PlantHydraulics
+using ClimaLand.Snow
+import ClimaLand.Simulations: LandSimulation, solve!
+import ClimaLand.Parameters as LP
+import ClimaLand.FluxnetSimulations as FluxnetSimulations
+using ClimaDiagnostics
+using ClimaUtilities
+
+# ── 2. Configuration ──────────────────────────────────────────────────────────
+const FT = Float64
+site_ID = "DK-Sor"
+site_ID_val = FluxnetSimulations.replace_hyphen(site_ID)
+climaland_dir = pkgdir(ClimaLand)
+toml_dict = LP.create_toml_dict(FT)
+
+# Simulation parameters
+dt = Float64(450) # 7.5 minutes
+# CalMIP Phase 1a simulation period (must be within MODIS LAI coverage: 2000-2020)
+start_date = DateTime(2008, 1, 1)
+stop_date = DateTime(2009, 1, 1) # Full year 2008
+
+# ── 3. Site metadata ──────────────────────────────────────────────────────────
+(; dz_tuple, nelements, zmin, zmax) =
+    FluxnetSimulations.get_domain_info(FT, Val(site_ID_val))
+(; time_offset, lat, long) =
+    FluxnetSimulations.get_location(FT, Val(site_ID_val))
+(; atmos_h) = FluxnetSimulations.get_fluxtower_height(FT, Val(site_ID_val))
+
+# ── 4. Domain ─────────────────────────────────────────────────────────────────
+land_domain = Column(;
+    zlim = (zmin, zmax),
+    nelements = nelements,
+    dz_tuple = dz_tuple,
+    longlat = (long, lat),
+)
+surface_space = land_domain.space.surface
+
+# ── 5. Atmospheric & radiation forcing ────────────────────────────────────────
+(; atmos, radiation) = FluxnetSimulations.prescribed_forcing_fluxnet(
+    site_ID,
+    lat,
+    long,
+    time_offset,
+    atmos_h,
+    start_date,
+    toml_dict,
+    FT;
+    split_precip = :callmip,
+)
+
+# ── 6. LAI from MODIS ─────────────────────────────────────────────────────────
+LAI =
+    ClimaLand.Canopy.prescribed_lai_modis(surface_space, start_date, stop_date)
+
+# ── 7. Build LandModel (all defaults) ────────────────────────────────────────
+prognostic_land_components = (:canopy, :snow, :soil, :soilco2)
+forcing = (; atmos, radiation)
+
+land = LandModel{FT}(
+    forcing,
+    LAI,
+    toml_dict,
+    land_domain,
+    dt;
+    prognostic_land_components,
+)
+
+# ── 8. Initial conditions ────────────────────────────────────────────────────
+set_ic! = FluxnetSimulations.make_set_fluxnet_initial_conditions(
+    site_ID,
+    start_date,
+    time_offset,
+    land,
+)
+
+# ── 9. Diagnostics ───────────────────────────────────────────────────────────
+outdir = joinpath(
+    pkgdir(ClimaLand),
+    "experiments/integrated/fluxnet/$(site_ID)/callmip_default/out",
+)
+mkpath(outdir)
+println("Output directory: ", outdir)
+
+output_writer = ClimaDiagnostics.Writers.NetCDFWriter(
+    land_domain.space.subsurface,
+    outdir;
+    start_date,
+)
+
+short_names_1D = [
+    "sif",
+    "ra",
+    "gs",
+    "gpp",
+    "ct",
+    "swu",
+    "lwu",
+    "er",
+    "et",
+    "msf",
+    "shf",
+    "lhf",
+    "rn",
+]
+short_names_2D = ["swc", "tsoil", "si", "sco2", "soc", "so2"]
+output_vars = [short_names_1D..., short_names_2D..., "swe"]
+
+diags = ClimaLand.default_diagnostics(
+    land,
+    start_date;
+    output_writer = output_writer,
+    output_vars,
+    reduction_period = :halfhourly,
+)
+
+# ── 10. Run simulation ───────────────────────────────────────────────────────
+simulation = LandSimulation(
+    start_date,
+    stop_date,
+    dt,
+    land;
+    set_ic!,
+    updateat = Second(dt),
+    diagnostics = diags,
+)
+solve!(simulation)
+
+# ── 11. Post-processing ──────────────────────────────────────────────────────
+println("\nSimulation completed successfully!")
+println("Start date: ", start_date)
+println("Stop date: ", stop_date)
+
+ClimaLand.Diagnostics.close_output_writers(diags)
+println("Output files written to: ", outdir)
+
+for file in readdir(outdir; join = false)
+    filepath = joinpath(outdir, file)
+    if isfile(filepath)
+        filesize_mb = round(stat(filepath).size / 1024^2, digits = 2)
+        println("  $file ($(filesize_mb) MB)")
+    end
+end
diff --git a/experiments/integrated/fluxnet/callmip_dksor_pmodel.jl b/experiments/integrated/fluxnet/callmip_dksor_pmodel.jl
new file mode 100644
index 00000000000..081166627eb
--- /dev/null
+++ b/experiments/integrated/fluxnet/callmip_dksor_pmodel.jl
@@ -0,0 +1,205 @@
+# ── DK-Sor CalMIP Phase 1a: PModel Configuration ─────────────────────────────
+#
+# This script runs the DK-Sor (Denmark Sorø) CalMIP Phase 1a site using the
+# high-level LandModel constructor with PModel photosynthesis overrides.
+#
+# Overridden sub-models:
+#   - Photosynthesis: PModel (optimality-based)
+#   - Conductance: PModelConductance (coupled with PModel)
+#   - Soil moisture stress: PiecewiseMoistureStressModel (θ-based, not ψ-based)
+#
+# Default sub-models (from LandModel constructor):
+#   - Radiative transfer: TwoStreamModel
+#   - Plant hydraulics: PlantHydraulicsModel
+#   - Energy: BigLeafEnergyModel
+#   - Snow: SnowModel (with default albedo)
+#   - Soil: EnergyHydrology (spatial defaults)
+#   - SoilCO2: SoilCO2Model
+#
+# For more information about the CalMIP project:
+# https://github.com/callmip-org/Phase1
+# https://callmip-org.github.io
+
+# ── 1. Imports ────────────────────────────────────────────────────────────────
+import ClimaLand
+import SciMLBase
+using ClimaCore
+import ClimaComms
+import ClimaParams as CP
+using Dates
+using Insolation
+
+using ClimaLand
+using ClimaLand: LandModel
+using ClimaLand.Domains: Column
+using ClimaLand.Soil
+using ClimaLand.Soil.Biogeochemistry
+using ClimaLand.Canopy
+using ClimaLand.Canopy.PlantHydraulics
+using ClimaLand.Snow
+import ClimaLand.Simulations: LandSimulation, solve!
+import ClimaLand.Parameters as LP
+import ClimaLand.FluxnetSimulations as FluxnetSimulations
+using ClimaDiagnostics
+using ClimaUtilities
+
+# ── 2. Configuration ──────────────────────────────────────────────────────────
+const FT = Float64
+site_ID = "DK-Sor"
+site_ID_val = FluxnetSimulations.replace_hyphen(site_ID)
+climaland_dir = pkgdir(ClimaLand)
+toml_dict = LP.create_toml_dict(FT)
+
+# Simulation parameters
+dt = Float64(450) # 7.5 minutes
+# CalMIP Phase 1a simulation period (must be within MODIS LAI coverage: 2000-2020)
+start_date = DateTime(2008, 1, 1)
+stop_date = DateTime(2009, 1, 1) # Full year 2008
+
+# ── 3. Site metadata ──────────────────────────────────────────────────────────
+(; dz_tuple, nelements, zmin, zmax) =
+    FluxnetSimulations.get_domain_info(FT, Val(site_ID_val))
+(; time_offset, lat, long) =
+    FluxnetSimulations.get_location(FT, Val(site_ID_val))
+(; atmos_h) = FluxnetSimulations.get_fluxtower_height(FT, Val(site_ID_val))
+
+# ── 4. Domain ─────────────────────────────────────────────────────────────────
+land_domain = Column(;
+    zlim = (zmin, zmax),
+    nelements = nelements,
+    dz_tuple = dz_tuple,
+    longlat = (long, lat),
+)
+surface_space = land_domain.space.surface
+canopy_domain = ClimaLand.Domains.obtain_surface_domain(land_domain)
+
+# ── 5. Atmospheric & radiation forcing ────────────────────────────────────────
+(; atmos, radiation) = FluxnetSimulations.prescribed_forcing_fluxnet(
+    site_ID,
+    lat,
+    long,
+    time_offset,
+    atmos_h,
+    start_date,
+    toml_dict,
+    FT;
+    split_precip = :callmip,
+)
+
+# ── 6. LAI from MODIS ─────────────────────────────────────────────────────────
+LAI =
+    ClimaLand.Canopy.prescribed_lai_modis(surface_space, start_date, stop_date)
+
+# ── 7. Custom canopy components (PModel overrides) ────────────────────────────
+prognostic_land_components = (:canopy, :snow, :soil, :soilco2)
+forcing = (; atmos, radiation)
+
+# PModel photosynthesis (optimality-based, requires PModelConductance)
+photosynthesis = PModel{FT}(canopy_domain, toml_dict)
+conductance = PModelConductance{FT}(toml_dict)
+
+# Soil moisture stress based on soil moisture (θ) rather than leaf water potential (ψ)
+soil_moisture_stress =
+    ClimaLand.Canopy.PiecewiseMoistureStressModel{FT}(land_domain, toml_dict)
+
+ground = ClimaLand.PrognosticGroundConditions{FT}()
+canopy_forcing = (; atmos, radiation, ground)
+
+# Construct canopy with PModel overrides; other components use defaults
+canopy = ClimaLand.Canopy.CanopyModel{FT}(
+    canopy_domain,
+    canopy_forcing,
+    LAI,
+    toml_dict;
+    prognostic_land_components,
+    photosynthesis,
+    conductance,
+    soil_moisture_stress,
+)
+
+# ── 8. Build LandModel with custom canopy ─────────────────────────────────────
+land = LandModel{FT}(
+    forcing,
+    LAI,
+    toml_dict,
+    land_domain,
+    dt;
+    prognostic_land_components,
+    canopy,
+)
+
+# ── 9. Initial conditions ────────────────────────────────────────────────────
+set_ic! = FluxnetSimulations.make_set_fluxnet_initial_conditions(
+    site_ID,
+    start_date,
+    time_offset,
+    land,
+)
+
+# ── 10. Diagnostics ──────────────────────────────────────────────────────────
+outdir = joinpath(
+    pkgdir(ClimaLand),
+    "experiments/integrated/fluxnet/$(site_ID)/callmip_pmodel/out",
+)
+mkpath(outdir)
+println("Output directory: ", outdir)
+
+output_writer = ClimaDiagnostics.Writers.NetCDFWriter(
+    land_domain.space.subsurface,
+    outdir;
+    start_date,
+)
+
+short_names_1D = [
+    "sif",
+    "ra",
+    "gs",
+    "gpp",
+    "ct",
+    "swu",
+    "lwu",
+    "er",
+    "et",
+    "msf",
+    "shf",
+    "lhf",
+    "rn",
+]
+short_names_2D = ["swc", "tsoil", "si", "sco2", "soc", "so2"]
+output_vars = [short_names_1D..., short_names_2D..., "swe"]
+
+diags = ClimaLand.default_diagnostics(
+    land,
+    start_date;
+    output_writer = output_writer,
+    output_vars,
+    reduction_period = :halfhourly,
+)
+
+# ── 11. Run simulation ───────────────────────────────────────────────────────
+simulation = LandSimulation(
+    start_date,
+    stop_date,
+    dt,
+    land;
+    set_ic!,
+    updateat = Second(dt),
+    diagnostics = diags,
+)
+solve!(simulation)
+
+# ── 12. Post-processing ──────────────────────────────────────────────────────
+println("\nSimulation completed successfully!")
+println("Start date: ", start_date)
+println("Stop date: ", stop_date)
+
+ClimaLand.Diagnostics.close_output_writers(diags)
+println("Output files written to: ", outdir)
+
+for file in readdir(outdir; join = false)
+    filepath = joinpath(outdir, file)
+    if isfile(filepath)
+        filesize_mb = round(stat(filepath).size / 1024^2, digits = 2)
+        println("  $file ($(filesize_mb) MB)")
+    end
+end
diff --git a/ext/FluxnetSimulationsExt.jl b/ext/FluxnetSimulationsExt.jl
index 2ec50608469..db2071e9cfb 100644
--- a/ext/FluxnetSimulationsExt.jl
+++ b/ext/FluxnetSimulationsExt.jl
@@ -27,6 +27,7 @@ include("fluxnet_simulations/US-MOz.jl")
 include("fluxnet_simulations/US-Ha1.jl")
 include("fluxnet_simulations/US-NR1.jl")
 include("fluxnet_simulations/US-Var.jl")
+include("fluxnet_simulations/DK-Sor.jl")  # CalMIP Phase 1a test site
 
 # Include the data processing, forcing, and initial conditions utilities.
 include("fluxnet_simulations/data_processing.jl")
diff --git a/ext/fluxnet_simulations/DK-Sor.jl b/ext/fluxnet_simulations/DK-Sor.jl
new file mode 100644
index 00000000000..49ff0569903
--- /dev/null
+++ b/ext/fluxnet_simulations/DK-Sor.jl
@@ -0,0 +1,196 @@
+#=
+This file contains domain specifications, parameters, and other site-level information for running
+ClimaLand at the DK-Sor (Denmark Sorø) CalMIP site.
+
+Site information:
+- Location: Sorø, Denmark (55.486°N, 11.6446°E)
+- Vegetation type: Deciduous Broadleaf Forest (Beech - Fagus sylvatica)
+- CalMIP Phase 1a test calibration site
+- Reference: https://github.com/callmip-org/Phase1
+=#
+
+"""
+    FluxnetSimulations.get_domain_info(FT, ::Val{:DK_Sor}; dz_bottom = FT(1.5), dz_top = FT(0.1),
+        nelements = 20, zmin = FT(-10), zmax = FT(0))
+
+Gets and returns primary domain information for the DK-Sor (Denmark Sorø) CalMIP site.
+Default parameters are provided and can be overriden using keyword arguments.
+"""
+function FluxnetSimulations.get_domain_info(
+    FT,
+    ::Val{:DK_Sor};
+    dz_bottom = FT(1.5),
+    dz_top = FT(0.1),
+    nelements = 20,
+    zmin = FT(-10),
+    zmax = FT(0),
+)
+    dz_tuple = (dz_bottom, dz_top)
+    return (; dz_tuple, nelements, zmin, zmax)
+end
+
+"""
+    get_location(FT, ::Val{:DK_Sor}; kwargs)
+
+Returns geographical information for DK-Sor (Denmark Sorø) CalMIP site.
+The values are provided as defaults, and can be overwritten by passing the
+corresponding keyword arguments to this function.
+
+The `time_offset` is the difference from UTC in hours
+and excludes daylight savings time, following Fluxnet convention.
+For this site, Denmark is in the Central European Time zone (CET), which is UTC+1.
+"""
+function FluxnetSimulations.get_location(
+    FT,
+    ::Val{:DK_Sor};
+    time_offset = 1,
+    lat = FT(55.486),
+    long = FT(11.6446),
+)
+    return (; time_offset, lat, long)
+end
+
+"""
+    get_fluxtower_height(FT, ::Val{:DK_Sor}; kwargs...)
+
+Returns atmosphere height for DK-Sor (Denmark Sorø) CalMIP site.
+The values are provided as defaults, and can be overwritten by passing the
+corresponding keyword arguments to this function.
+"""
+function FluxnetSimulations.get_fluxtower_height(
+    FT,
+    ::Val{:DK_Sor};
+    atmos_h = FT(57),
+)
+    return (; atmos_h,)
+end
+
+"""
+    get_parameters(FT, ::Val{:DK_Sor}; kwargs...)
+
+Gets parameters for the CalMIP site DK-Sor (Denmark Sorø), which is a Deciduous Broadleaf Forest
+dominated by beech trees (Fagus sylvatica), and returns them as a Named Tuple. 
+The values are provided as defaults, and can be overwritten by passing the 
+corresponding keyword arguments to this function.
+
+Note: These parameters are initial estimates and should be calibrated using CalMIP protocol.
+For calibration targets and observations, see the CalMIP Phase 1 protocol at:
+https://github.com/callmip-org/Phase1
+
+Data sources:
+- Site characteristics from CalMIP Phase 1 protocol
+- Initial parameter estimates based on deciduous broadleaf forest typical values
+- Conductance parameters adapted from Wang et al. 2021 https://doi.org/10.5194/gmd-14-6741-2021
+"""
+function FluxnetSimulations.get_parameters(
+    FT,
+    ::Val{:DK_Sor};
+    # Soil hydraulic and thermal parameters
+    soil_ν = FT(0.50),
+    soil_K_sat = FT(5e-7),
+    soil_S_s = FT(1e-2),
+    soil_vg_n = FT(1.8),
+    soil_vg_α = FT(0.04),
+    θ_r = FT(0.05),
+    # Soil composition
+    ν_ss_quartz = FT(0.15),
+    ν_ss_om = FT(0.12),
+    ν_ss_gravel = FT(0.0),
+    # Soil surface properties
+    z_0m_soil = FT(0.01),
+    z_0b_soil = FT(0.01),
+    soil_ϵ = FT(0.98),
+    soil_α_PAR = FT(0.15),
+    soil_α_NIR = FT(0.15),
+    # Canopy structure parameters
+    Ω = FT(0.70),
+    χl = FT(0.1),
+    G_Function = ConstantGFunction(FT(0.5)),
+    # Leaf optical properties
+    α_PAR_leaf = FT(0.11),
+    λ_γ_PAR = FT(5e-7),
+    τ_PAR_leaf = FT(0.05),
+    α_NIR_leaf = FT(0.40),
+    τ_NIR_leaf = FT(0.25),
+    # Canopy radiative properties
+    ϵ_canopy = FT(0.97),
+    ac_canopy = FT(5e2),
+    # Photosynthesis and stomatal conductance parameters
+    g1 = FT(150),
+    Drel = FT(1.6),
+    g0 = FT(1e-4),
+    Vcmax25 = FT(6.5e-5),
+    # Water stress parameters
+    pc = FT(-2.0e6),
+    sc = FT(5e-6),
+    # Structural parameters
+    SAI = FT(1.0),
+    f_root_to_shoot = FT(3.0),
+    # Plant hydraulics parameters
+    K_sat_plant = 8e-8,
+    ψ63 = FT(-4 / 0.0098),
+    Weibull_param = FT(4),
+    a = FT(0.1 * 0.0098),
+    conductivity_model = PlantHydraulics.Weibull{FT}(
+        K_sat_plant,
+        ψ63,
+        Weibull_param,
+    ),
+    retention_model = PlantHydraulics.LinearRetentionCurve{FT}(a),
+    plant_ν = FT(1.44e-4),
+    plant_S_s = FT(1e-2 * 0.0098),
+    # Root and canopy height parameters
+    rooting_depth = FT(1.0),
+    n_stem = Int64(1),
+    n_leaf = Int64(1),
+    h_stem = FT(25),
+    h_leaf = FT(5),
+    h_canopy = h_stem + h_leaf,
+)
+    return (;
+        soil_ν,
+        soil_K_sat,
+        soil_S_s,
+        soil_vg_n,
+        soil_vg_α,
+        θ_r,
+        ν_ss_quartz,
+        ν_ss_om,
+        ν_ss_gravel,
+        z_0m_soil,
+        z_0b_soil,
+        soil_ϵ,
+        soil_α_PAR,
+        soil_α_NIR,
+        Ω,
+        χl,
+        G_Function,
+        α_PAR_leaf,
+        λ_γ_PAR,
+        τ_PAR_leaf,
+        α_NIR_leaf,
+        τ_NIR_leaf,
+        ϵ_canopy,
+        ac_canopy,
+        g1,
+        Drel,
+        g0,
+        Vcmax25,
+        SAI,
+        f_root_to_shoot,
+        K_sat_plant,
+        ψ63,
+        Weibull_param,
+        a,
+        conductivity_model,
+        retention_model,
+        plant_ν,
+        plant_S_s,
+        rooting_depth,
+        n_stem,
+        n_leaf,
+        h_leaf,
+        h_stem,
+        h_canopy,
+    )
+end
diff --git a/ext/fluxnet_simulations/data_processing.jl b/ext/fluxnet_simulations/data_processing.jl
index 0684930f446..0d59a9a2046 100644
--- a/ext/fluxnet_simulations/data_processing.jl
+++ b/ext/fluxnet_simulations/data_processing.jl
@@ -163,9 +163,21 @@ end
 Reads Fluxnet CSV data for the provided site, and returns a tuple `(data, columns)`
 where `data` is a `n_rows x n_cols` Matrix of the data, and `columns` is a
 `1 x n_cols` Matrix of column names.
+
+This function now supports both standard Fluxnet sites and CalMIP sites.
+For CalMIP sites (e.g., "DK-Sor"), it uses the callmip_data_path function.
 """
 function read_fluxnet_data(site_ID)
-    fluxnet_csv_path = ClimaLand.Artifacts.experiment_fluxnet_data_path(site_ID)
+    # Check if this is a CalMIP site
+    callmip_sites = ("DK-Sor",)  # Add more CalMIP sites here as needed
+
+    if site_ID ∈ callmip_sites
+        fluxnet_csv_path = ClimaLand.Artifacts.callmip_data_path(site_ID)
+    else
+        fluxnet_csv_path =
+            ClimaLand.Artifacts.experiment_fluxnet_data_path(site_ID)
+    end
+
     (data, columns) = readdlm(fluxnet_csv_path, ','; header = true)
 
     return (data, columns)
diff --git a/ext/fluxnet_simulations/forcing.jl b/ext/fluxnet_simulations/forcing.jl
index de4020e7738..9a63bf2a8d0 100644
--- a/ext/fluxnet_simulations/forcing.jl
+++ b/ext/fluxnet_simulations/forcing.jl
@@ -28,6 +28,11 @@ which is why we drop missing data. For the timestamp of the observation, we use
 the halfway point between the timestamp start and timestamp end:
 see https://fluxnet.org/data/fluxnet2015-dataset/fullset-data-product/ for details.
 
+The `split_precip` keyword argument controls rain/snow partitioning:
+- `true` or `:jennings`: Jennings et al. (2018) logistic function using temperature and humidity
+- `:callmip`: CalMIP Phase 1 binary threshold (Tair < 273.15K → snow, >= 273.15K → rain)
+- `false`: No splitting (all precipitation treated as rain)
+
 This assumes that the first row of the CSV file is the list of of column names,
 and that these names are:
 "TA_F" (air temperature in C)
@@ -153,7 +158,30 @@ function FluxnetSimulations.prescribed_forcing_fluxnet(
     # Convert to a flux using data_dt. Also, change the sign, because in ClimaLand
     # precipitation is a downward flux (negative), and convert from accumulated mm to m/s
     data_dt = Second(UTC_datetimes[2] - UTC_datetimes[1]).value # seconds
-    if split_precip
+    if split_precip == :callmip
+        # CalMIP Phase 1 protocol: binary threshold at 273.15K (0°C)
+        # Tair < 273.15K → all snow, Tair >= 273.15K → all rain
+        # TA_F is in °C, so threshold is 0°C
+        compute_rain_callmip(T, precip) =
+            T >= 0 ? -precip / 1000 / data_dt : zero(precip)
+        compute_snow_callmip(T, precip) =
+            T < 0 ? -precip / 1000 / data_dt : zero(precip)
+        atmos_P_liq = time_varying_input_from_data(
+            data,
+            ["TA_F", "P_F"],
+            column_name_map,
+            seconds_since_start_date;
+            preprocess_func = compute_rain_callmip,
+        )
+        atmos_P_snow = time_varying_input_from_data(
+            data,
+            ["TA_F", "P_F"],
+            column_name_map,
+            seconds_since_start_date;
+            preprocess_func = compute_snow_callmip,
+        )
+    elseif split_precip == true || split_precip == :jennings
+        # Jennings et al. (2018) logistic function using temperature and humidity
         compute_rain(T, VPD, precip; thermo_params = thermo_params) =
             -1 * precip / 1000 / data_dt *
             (1 - snow_precip_fraction(T, VPD; thermo_params))
@@ -366,6 +394,14 @@ Estimate the fraction of precipitation that is in snow form,
 given the air temperature at the surface in C and the vapor pressure
 deficit in hPa.
 
+Uses a logistic function based on temperature and relative humidity,
+which provides a smooth transition between rain and snow phases.
+Used when `split_precip=true` or `split_precip=:jennings`.
+
+For CalMIP experiments, use `split_precip=:callmip` in
+`prescribed_forcing_fluxnet` instead, which applies the CalMIP Phase 1
+binary threshold (Tair < 273.15K → snow, Tair >= 273.15K → rain).
+
 See Jennings, K.S., Winchell, T.S., Livneh, B. et al.
 Spatial variation of the rain–snow temperature threshold across the
 Northern Hemisphere. Nat Commun 9, 1148 (2018).
diff --git a/ext/fluxnet_simulations/initial_conditions.jl b/ext/fluxnet_simulations/initial_conditions.jl
index 3900572755f..b74c9d53b11 100644
--- a/ext/fluxnet_simulations/initial_conditions.jl
+++ b/ext/fluxnet_simulations/initial_conditions.jl
@@ -47,7 +47,15 @@ function set_fluxnet_ic!(
     hour_offset_from_UTC,
     model::ClimaLand.AbstractLandModel,
 )
-    fluxnet_csv_path = ClimaLand.Artifacts.experiment_fluxnet_data_path(site_ID)
+    # Check if this is a CalMIP site
+    callmip_sites = ("DK-Sor",)  # Add more CalMIP sites here as needed
+
+    if site_ID ∈ callmip_sites
+        fluxnet_csv_path = ClimaLand.Artifacts.callmip_data_path(site_ID)
+    else
+        fluxnet_csv_path =
+            ClimaLand.Artifacts.experiment_fluxnet_data_path(site_ID)
+    end
 
     # Read the data and get the column name map
     (data, columns) = readdlm(fluxnet_csv_path, ','; header = true)
@@ -99,9 +107,9 @@ function set_fluxnet_ic!(
     )
     FT = eltype(Y.soil.ρe_int)
     if isnothing(column_name_map["SWC_F_MDS_1"])
-        θ_l_0 = model.parameters.ν / 2
+        θ_l_0 = model.parameters.ν ./ 2
     elseif unique(data[:, column_name_map["SWC_F_MDS_1"]]) == val
-        θ_l_0 = model.parameters.ν / 2
+        θ_l_0 = model.parameters.ν ./ 2
     else
         θ_l_0 =
             min.(
diff --git a/src/Artifacts.jl b/src/Artifacts.jl
index 0d616b367fc..89f3372284b 100644
--- a/src/Artifacts.jl
+++ b/src/Artifacts.jl
@@ -317,6 +317,49 @@ function experiment_fluxnet_data_path(site_ID; context = nothing)
     return data_path
 end
 
+"""
+    callmip_data_path(site_ID; context = nothing)
+
+Return the path to the file that contains forcing data for a CalMIP site.
+Currently supports DK-Sor (Denmark Sorø) for CalMIP Phase 1a test calibration.
+
+Site information:
+DK-Sor (Denmark Sorø):
+- Location: 55.486°N, 11.6446°E
+- Vegetation: Deciduous Broadleaf Forest (Beech)
+- CalMIP Phase 1a test site
+
+For more information see: https://github.com/callmip-org/Phase1
+
+TODO: CalMIP data needs to be added to ClimaArtifacts.
+For now, this expects the CSV files to be available locally.
+Users should download CalMIP forcing data from:
+- https://github.com/callmip-org/Phase1/tree/main/Data
+- https://modelevaluation.org
+"""
+function callmip_data_path(site_ID; context = nothing)
+    @assert site_ID ∈ ("DK-Sor",)
+
+    # TODO: Once CalMIP data is added to ClimaArtifacts, use:
+    # folder_path = @clima_artifact("callmip_sites", context)
+    # data_path = joinpath(folder_path, "$(site_ID).csv")
+
+    # For now, expect users to provide the path via environment variable
+    # or use a default path
+    if haskey(ENV, "CALLMIP_DATA_PATH")
+        data_path = joinpath(ENV["CALLMIP_DATA_PATH"], "$(site_ID).csv")
+    else
+        # Default to sampo data directory
+        data_path = joinpath(
+            "/net/sampo/data1/renatob",
+            "callmip_forcing",
+            "$(site_ID).csv",
+        )
+    end
+
+    return data_path
+end
+
 """
     esm_snowmip_data_path(; context = nothing)