maritime_galleon_transit_times
Compute transit days for Manila Galleon voyages across the Pacific. Use eastbound crossing times as an ENSO proxy to evaluate historical El Niño and La Niña effects.
Instructions
Compute transit times for Manila Galleon voyages (1565-1815).
Returns per-voyage transit days (arrival_date - departure_date) for 250 years of Pacific crossings. The galleon trade provides direct tropical Pacific exposure through the ENSO-affected trade wind belt, making transit times a potential ENSO proxy.
Args: trade_direction: "eastbound" (Acapulco→Manila, trade-wind route, ~75 days) or "westbound" (Manila→Acapulco, northern route, ~165 days) year_start: Earliest departure year (inclusive) year_end: Latest departure year (inclusive) fate: Filter by voyage fate ("completed", "wrecked", etc.) max_results: Maximum records to return (default: 500) output_mode: Response format - "json" (default) or "text"
Returns: JSON or text with transit records and summary statistics
Tips for LLMs: - Eastbound galleons are the best ENSO detector: they sail directly through the trade wind belt - During El Nino (weakened trades), eastbound crossings should take LONGER; during La Nina (stronger trades), FASTER - Westbound route goes north via Kuroshio Current at ~38N, less directly affected by tropical ENSO - Use trade_direction="eastbound" for ENSO analysis - Compare transit_days across known ENSO years vs neutral years - 213 voyages have complete transit data (of 250 total) - Mean eastbound: 75 days (std 14); westbound: 165 days (std 17)
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| trade_direction | No | ||
| year_start | No | ||
| year_end | No | ||
| fate | No | ||
| max_results | No | ||
| output_mode | No | json |