Pacific Ocean one branch flows around Cape Horn and the other turns north to form the Peru or Humboldt Current. The climate patterns of the Northern and Southern Hemispheres generally mirror each other. The trade winds in the southern and eastern Pacific are remarkably steady while conditions in the North Pacific are far more varied with, for example, cold winter temperatures on the east coast of Russia contrasting with the milder weather off British Columbia during the winter months due to the preferred flow of ocean currents. In the tropical and subtropical Pacific, the El Niño Southern Oscillation (ENSO) affects weather conditions.
Spanish expeditions to the Pacific Northwest Spanish expeditions to the Pacific Northwest Spanish claims to Alaska and the West Coast of North America date to the papal bull of 1493, and the Treaty of Tordesillas. In 1513, this claim was reinforced by Spanish explorer Vasco Núñez de Balboa, the first European to sight the Pacific Ocean, when he claimed all lands adjoining this ocean for the Spanish Crown. Spain only started to colonize the claimed territory north of present-day Mexico in the 18th century, when it settled the northern coast of Las Californias (California). Starting in the mid-18th century, Spain's rights began to be challenged by