What is the Humboldt Current (Corriente de Humboldt / Corriente de Chile), and how does it fundamentally influence coastal weather along the Chilean littoral?

1. A cold, northward-flowing eastern boundary ocean current that lowers coastal sea surface temperatures, stabilizes the lower atmosphere, creates a persistent thermal inversion, and produces coastal fog and arid conditions
2. A warm tropical current flowing south that causes frequent hurricanes and tropical cyclones along northern Chile
3. A subterranean freshwater river that discharges into the Gulf of Ancud
4. A seasonal high-salinity current that reverses direction every 24 hours with the lunar cycle