Buenos Aires is classified as a Cfa koppen climate a temperate climate that is characteristic of the Río de la Plata river coast, this area is a littoral region with several rivers converging into the ocean. Buenos Aires typically is hot and humid during the December through February, the average high temperature is around 83°F. Fall and spring are characterized by unpredictable temperatures and sporadic weather systems.
The fall and winter months range from June to August and are mild and can still be pretty humid. The average temperature is around 52°F. The average annual temperature is a little higher at 60° F. Frosts do occur in Buenos Aires despite the temperate climate. Within the city of Buenos Aires snowfall is extremely rare however in 2007 there was a significant snowfall. This snow was the first significant snowfall in the city in almost 90 years!
|
 |
| Snow in Buenos Aires! |
Occasionally Buenos Aires experiences extreme weather patterns that bring flooding, hail, tornadoes, and electrical storms. The meso-scale climate controls that affect Buenos Aires most significantly are the ocean currents to the east, primarily the Falkland current and Brazilian current. The large Andes Mountains to the west are extremely high and provide no major protection for Buenos Aires; however they do affect airflows over the continent and can contribute to weather or lack of weather on the East coast where Buenos Aires lays. The mid-latitude location of Buenos Aires situates the city right around a semi-permanent high pressure that shifts north and south throughout the seasons. The mid-latitude location of the city make for a very dynamic area for converging warm wet maritime and dry cold polar air masses. This is very significant to the location of the city.
A mirco-climate factor for Buenos Aires is the urban heat island; temperatures in the city can be on average 8° F warmer. However sometimes, “The average value of the maximal heat island fell in winter from 4.6°C with light winds and little sky coverage to 3.6°C with windy and cloudy conditions. Strong winds from the city toward rural areas and winds from the river over the city facilitated the occurrence of an inverse heat island (rural area warmer than city).” (1) The urban heat island information can vary greatly depending on what part of the city the information is derived. Portions of the interior have more pronounced urban heat temperatures than the coastal or western regions. Another anthropological climate factor is pollution. Pollution in Buenos Aires comes from mostly cars and some industry. Since 1950 the amount of cars in Buenos Aires has increase significantly contributing to higher levels of pollution. During the winter months the city can experience temperature inversions that trap pollution within the city. This pollution amplifies the greenhouse effect by trapping more heat in the latent heat flux and creates smoggy dreary days during the winter months.
With Brazil and the densely vegetated Amazon to the north, Buenos Aires experiences a lot of humidity and heat from its northern neighbor. As Buenos Aires moves into summer months the moist maritime air masses from the north become heavy with moisture from heavy plant transpiration and begin to push south. The northern air brings large moist tropical air masses from Brazil, the convergence of the extremely wet air masses and the cold polar air masses cause precipitation, sometimes flash flooding. These moist air masses from the tropical north cause for consistent precipitation throughout the year but more pronounced events in the spring and fall months.
Authors Mirta E. Quattrocchio and Ana M. Borromei suggest that “Late Holocene climates show greater variability and they suggest the onset of modern environmental conditions as represented by cool and wet conditions in southern Tierra del Fuego, and by arid to semi-arid conditions in southwestern Buenos Aires Province.” (2) It seems that Buenos Aires has gone through periods of extreme dry as well as periods of extreme wet.
Sources
Climate information is also available for the following climate stations in Argentina: |
No comments:
Post a Comment