maritime_aggregate_track_speeds
Aggregate and analyze historical daily sailing speeds from logbook positions filtered by region, nationality, wind force, and time period, grouping results by decade, year, direction, or other dimensions to reveal trends.
Instructions
Aggregate daily sailing speeds across all matching CLIWOC tracks.
Computes haversine-based daily speeds from consecutive logbook positions, filters by geographic region, and aggregates by the requested dimension. Returns descriptive statistics per group.
Args: group_by: Grouping dimension. Options: - "decade" — group by decade (e.g., 1750, 1760, ...) - "year" — group by individual year (e.g., 1783, 1784, ...) - "month" — group by month (1-12) - "direction" — group by eastbound/westbound - "nationality" — group by ship nationality (NL, UK, ES, ...) - "beaufort" — group by Beaufort wind force (0-12) lat_min: Minimum latitude for position bounding box lat_max: Maximum latitude for position bounding box lon_min: Minimum longitude for position bounding box lon_max: Maximum longitude for position bounding box nationality: Filter tracks by nationality code (NL, UK, ES, FR, etc.) year_start: Filter tracks starting from this year year_end: Filter tracks ending at this year direction: Filter observations by "eastbound" or "westbound" month_start: Filter by start month (1-12). Supports wrap-around with month_end (e.g., month_start=11, month_end=2 = Nov-Feb) month_end: Filter by end month (1-12). Used with month_start aggregate_by: Unit of analysis — "observation" (default, each daily speed is a data point) or "voyage" (one mean speed per voyage, statistically independent samples) min_speed_km_day: Minimum speed filter (default: 5.0) max_speed_km_day: Maximum speed filter (default: 400.0) wind_force_min: Minimum Beaufort force (0-12). Requires wind data wind_force_max: Maximum Beaufort force (0-12). Requires wind data output_mode: Response format - "json" (default) or "text"
Returns: JSON or text with per-group statistics (n, mean, median, std, 95% CI, percentiles)
Tips for LLMs: - Use lat_min=-50, lat_max=-30 for the Roaring Forties wind belt - group_by="decade" shows speed trends over time - group_by="direction" shows eastbound vs westbound asymmetry - group_by="beaufort" shows speed profiles by wind force - Use aggregate_by="voyage" for statistically independent samples - Use wind_force_min/max to condition on wind strength - Use maritime_compare_speed_groups for significance testing - Use maritime_did_speed_test for direction x period interaction
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| group_by | No | decade | |
| lat_min | No | ||
| lat_max | No | ||
| lon_min | No | ||
| lon_max | No | ||
| nationality | No | ||
| year_start | No | ||
| year_end | No | ||
| direction | No | ||
| month_start | No | ||
| month_end | No | ||
| aggregate_by | No | observation | |
| min_speed_km_day | No | ||
| max_speed_km_day | No | ||
| wind_force_min | No | ||
| wind_force_max | No | ||
| output_mode | No | json |