Río Negro (, Black River) is a province of Argentina, located in northern Patagonia. Neighboring provinces are from the south clockwise Chubut, Neuquén, Mendoza, La Pampa and Buenos Aires. To the east lies the Atlantic Ocean.
Its capital is Viedma near the Atlantic outlet of the province's namesake river in the eastern extreme. The largest city is in the Andean foothills Bariloche in the far west. Other important cities include General Roca and Cipolletti.
History
Ferdinand Magellan was the first European explorer to visit the coasts of the provinces in 1520. Italian priest Nicolás Mascardi founded the Jesuit mission Nuestra Señora de Nahuel Huapi in 1670 at the shore of the Nahuel Huapi Lake, at the feet of the Andes range.
Originally part of the Argentine territory called Patagonia (in 1878 the Gobernación de la Patagonia), in 1884 it was organised into the Territorio Nacional del Río Negro and General Lorenzo Vintter was appointed as the territory's first governor. It was only in 1957, that Río Negro acquired status of a province; its first provincial governor was Edgardo Castello of the Radical Civic Union (UCR).
Geography
Río Negro is one of the six provinces that make up Argentine Patagonia. It is bounded to the north by the Colorado River which separates it from La Pampa Province, to the east by the Atlantic Ocean and to the west by the Andes and the Limay River (serves as the natural border with Neuquén Province). The 42nd parallel south marks the southern limit of the province. With an area of , it is the 4th largest province by area.
Climate
The climate of the province is temperate at low elevations, and very cold in the higher Andean peaks.
Temperature
The mean annual temperatures in the province are relatively cold for its latitude owing to the marine currents to the east and higher altitude to the west. Mean annual temperatures in the province can vary, depending on altitude and distance from the sea. The northern parts of the province are the warmest, with a mean annual temperature of more than while the coldest areas are found in the Cordillera where the mean annual temperatures are less than . At the highest peaks, the mean annual temperature is less than freezing. Summer temperatures can exceed although the mean January temperatures range from . In contrast, the Andean region has milder summers with mean January temperatures of or less, depending on the altitude. In July, mean temperatures range from on the coast in the north to around in the central plateau.
Humidity and precipitation
Relative humidity is lower in the central plateau where they average 50%. Along the coastal regions, humidity is higher with a mean annual humidity of 60% while the Andean region has the highest humidity with an average annual humidity exceeding 65% due to the lower temperatures there. In all locations, humidity is lower in the summer and higher in the winter owing to the higher temperatures in the summer.
The Andes block most of the moisture from the Pacific Ocean from coming in, causing it to release most of the precipitation on its western slopes and as such, most of the province is dry, with a mean annual precipitation around . Coastal areas and northern parts of the province receive a slightly higher precipitation, where it can average above a year. The Andean region receives the most precipitation with areas receiving a mean annual precipitation of in which the precipitation gradient is very strong and increases westwards. In some places, precipitation can exceed a year. Most of the Andean region has a rainfall pattern that is Mediterranean like, similar to Central Chile in which most of the precipitation falls during the winter months and summers are dry.
Wind and sunshine
One dominant characteristic of the climate is the strong winds that are observed throughout the province. Summers tend to be windier than winters. Winds coming from the west, southwest and northwest are common, occurring 50% of the time (60% if calm winds are not included). There is some tendency for the winds to come from the east, particularly on the coastal regions when sea breezes from the east can occur when westerly winds are weak, which can be felt up to from the coast. The mean wind speed throughout the province varies with the northern parts having the lowest wind speeds while the highest altitude areas being the windiest. Except for the northern parts of the province, mean annual wind speeds exceed .