Although the centre and the eastern parts of the country are mostly flat, the west is mountainous. Both the Andes and Sierras Pampeanas affect the climate of Argentina, leading to differences in temperature, pressure, and spatial distribution of precipitation depending on the topography and altitude. Here, the Andes exert an important influence on the climate. Owing to the higher altitudes of the Andes north of 40 S, they completely block the normal westerly flow, preventing low pressure systems containing moisture from the Pacific Ocean from coming in. Thus, much of Argentina north of 40 S is dominated by wind circulation patterns from the South Atlantic High. South of 40 S, the Andes are lower in altitude, allowing much of Patagonia to be dominated by westerly winds and air masses from the Pacific Ocean. However, the north -- south orientation of the Andes creates a barrier for humid air masses originating from the Pacific Ocean. This is because they force these air masses upwards, cooling adiabactically. Most of the moisture is dropped on the Chilean side, causing abundant precipitation and cloudiness while on the Argentine side, the air warms adiabatically, causing it to become drier as it descends. Thus, an extensive rain -- shadow is present in much of Patagonia, causing it to receive very little precipitation. The Sierras Pampeanas influences the climate on a much smaller scale than the Andes.
Explorers flying the flag of Spain reached the New World beginning in 1492 with the discovery of America by Christopher Columbus. Spanish expeditions colonized and explored vast areas in North and South America following the grants of the Pope (contained in the 1493 papal bull Inter caetera) and rights contained in the 1494 Treaty of Tordesillas and 1529 Treaty of Zaragoza. These formal acts gave Spain the exclusive rights to colonize the entire Western Hemisphere (excluding eastern Brazil), including all of the west coast of North America. The first European expedition to actually reach the west coast was led by the Spaniard Vasco Núñez de Balboa, who reached the Pacific coast of Panama in 1513. In an act of enduring historical importance, Balboa claimed the Pacific Ocean for the Spanish Crown, as well as all adjoining land and islands. This act gave Spain exclusive sovereignty and navigation rights over the entire west coast of North America.
Hernán Gumy (born 5 March 1972) is a former tennis player from Argentina, who turned professional in 1991. He represented his native country at the 1996 Summer Olympics in Atlanta, Georgia, where he was defeated in the first round by Venezuela's Nicolas Pereira. Gumy made two finals in his career; both of them ATP 250s on clay in 1996. He won Santiago, Chile (his final tournament of 1996) by beating the Spanish World No. 15 Félix Mantilla in a tough three-setter: in the semi-finals, and the Chilean world number 11 Marcelo Ríos in the final 6-4, 7-5. He lost the other final he was in, in Oporto, Portugal to Spain's Félix Mantilla despite winning the first set.

Question: Who was the first European in America to see the ocean where warm moist air mass over the Andes Mountains in the country Hernán Gumy is from originates?
Answer: Spaniard Vasco Núñez de Balboa