TrackSIC

A Python tool for extracting sea ice concentration data along vessel tracks. This tool processes satellite-derived sea ice concentration data from the University of Bremen and correlates it with ship position data to create time series and spatial visualizations.

Data Sources

Sea Ice Concentration Data

• Source: University of Bremen MODIS-Aqua/AMSR2 merged products
• URL: https://data.seaice.uni-bremen.de/modis_amsr2/geotiff/Arctic/
• Format: GeoTIFF files with 1km spatial resolution
• Coverage: Northern Hemisphere Arctic Ocean
• Temporal Resolution: Daily
• Data Range: 0-100% sea ice concentration

Position Data

• Format: Custom position files with degrees/minutes notation or standard CSV
• Required Fields: Date, time, latitude, longitude
• Projection: WGS84 (EPSG:4326)

Features

Core Analysis

• Automated download of sea ice concentration data
• Coordinate transformation between WGS84 and polar stereographic projections
• Daily averaging of high-frequency position data
• Extraction of ice concentration values at vessel positions
• Statistical analysis and data quality control

Visualization

• Time series plots of sea ice concentration along track
• Daily spatial maps showing ice conditions in 75km radius around vessel
• Temporal context with ±10-day historical tracks
• Animated sequences showing ice evolution over time
• Consistent color scaling optimized for high ice concentration detection (80-100%)

Installation

git clone https://github.com/kuivi/TrackSIC.git
cd TrackSIC
pip install -r requirements.txt

Usage

Basic Analysis

Extract sea ice concentration along vessel track:

python sic_extractor.py position_mosaic.dat

Advanced Visualization

Create daily maps and animation:

python sic_map_plotter.py position_mosaic.dat

Input File Formats

Position Mosaic Format

date time    latd    latm    hemlat  lond    lonm    hemlon
2019/09/20 15:20:00 69 40.772868 N 018 59.799306 E
2019/09/20 15:30:00 69 40.772844 N 018 59.799234 E

CSV Format

datetime,latitude,longitude
2019-09-20 15:20:00,69.679547,18.996655
2019-09-20 15:30:00,69.679547,18.996654

Output

Data Files

• output/sic_results.csv: Extracted SIC values with coordinates and dates
• output/sic_plot.png: Time series visualization

Spatial Analysis

• output/daily_maps/: Individual daily maps (when using map plotter)
• output/sic_movie.gif: Animated sequence of daily ice conditions

Technical Details

Coordinate Systems

• Input coordinates: WGS84 (EPSG:4326)
• SIC data projection: NSIDC Sea Ice Polar Stereographic North (EPSG:3411)
• Automatic coordinate transformation using pyproj

Data Processing

• Temporal aggregation to daily mean positions
• Spatial extraction within 75km radius of vessel positions
• Data validation and quality control (0-100% range clamping)
• Intelligent file caching to avoid redundant downloads

Dependencies

• pandas: Data manipulation and analysis
• numpy: Numerical computations
• rasterio: Geospatial raster data processing
• pyproj: Coordinate reference system transformations
• matplotlib: Visualization and plotting
• requests: HTTP data downloading

Example Results

The toolkit generates:

1. Time series: ice concentration along the track
2. Spatial context maps: Daily ice conditions with vessel position and historical context
3. Animated visualizations: Temporal evolution of ice conditions