Mountain jets are a type of jet stream created by surface winds channeled through mountain passes, sometimes causing high wind speeds and drastic temperature changes.

Central America jets

The North Pacific east of about 120°W is strongly influenced by winds blowing through gaps in the Central American cordillera. Air flow in the region forms the Intra-Americas Low-Level Jet, a westward flow about 1 km above sea level. This flow, trade winds, and cold air flowing south from North America contribute to winds flowing through several mountain valleys. Along

Central America Central America ( es, América Central or ) is a subregion of the Americas. Its boundaries are defined as bordering the United States to the north, Colombia to the south, the Caribbean Sea to the east, and the Pacific Ocean to the west. ...

are three main wind jets through breaks in the

American Cordillera The American Cordillera is a chain of mountain ranges ( cordilleras) that consists of an almost continuous sequence of mountain ranges that form the western "backbone" of North America, Central America and South America, with Aconcagua as ...

, on the

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the contine ...

side due to prevailing winds. *

Tehuano wind Tehuantepecer, or Tehuano wind, is a violent mountain-gap wind that travels through the Chivela Pass in southern Mexico, across the Isthmus of Tehuantepec. It is most common between October and February, with a summer minimum in July. It originate ...

blows from the

Gulf of Mexico The Gulf of Mexico ( es, Golfo de México) is an ocean basin and a marginal sea of the Atlantic Ocean, largely surrounded by the North American continent. It is bounded on the northeast, north and northwest by the Gulf Coast of the United S ...

through Chivela Pass in

Mexico Mexico ( Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guate ...

Isthmus of Tehuantepec The Isthmus of Tehuantepec () is an isthmus in Mexico. It represents the shortest distance between the Gulf of Mexico and the Pacific Ocean. Before the opening of the Panama Canal, it was a major overland transport route known simply as t ...

and out over the

Gulf of Tehuantepec Gulf of Tehuantepec () is a large body of water on the Pacific coast of the Isthmus of Tehuantepec, southeastern Mexico, at . Many (but not all) Pacific hurricanes form in or near this body of water. A strong, gale-force wind called the Teh ...

on the Pacific coast. Chivela Pass is a gap between the

Sierra Madre del Sur The Sierra Madre del Sur is a mountain range in southern Mexico, extending from southern Michoacán east through Guerrero, to the Isthmus of Tehuantepec in eastern Oaxaca. Geography The Sierra Madre del Sur joins with the Eje Volcánico Trans ...

and the Sierra Madre range to the south. * Papagayo wind shrieks over the lakes of

Nicaragua Nicaragua (; ), officially the Republic of Nicaragua (), is the largest Sovereign state, country in Central America, bordered by Honduras to the north, the Caribbean Sea, Caribbean to the east, Costa Rica to the south, and the Pacific Ocean to ...

and pushes far out over the Gulf of Papagayo on the Pacific coast. The Cordillera Central Mountains rise to the south, gradually descending to Gatun Lake and the

Isthmus of Panama The Isthmus of Panama ( es, Istmo de Panamá), also historically known as the Isthmus of Darien (), is the narrow strip of land that lies between the Caribbean Sea and the Pacific Ocean, linking North and South America. It contains the country ...

. * Panama winds slice through to the Pacific through the Gaillard Cut in

Panama Panama ( , ; es, link=no, Panamá ), officially the Republic of Panama ( es, República de Panamá), is a transcontinental country spanning the southern part of North America and the northern part of South America. It is bordered by Co ...

, which also holds the

Panama Canal The Panama Canal ( es, Canal de Panamá, link=no) is an artificial waterway in Panama that connects the Atlantic Ocean with the Pacific Ocean and divides North and South America. The canal cuts across the Isthmus of Panama and is a Channel ( ...

Cause

The air flow is due to surges of cold dense air originating from the North American continent. The meteorological mechanism that causes Tehuano and Papagayo winds is relatively simple. In the winter, cold high-pressure weather systems move southward from North America over the Gulf of Mexico. These high pressure systems create strong pressure gradients between the atmosphere over the Gulf of Mexico and the warmer, moister atmosphere over the Pacific Ocean. Just as a river flows from high elevations to lower elevations, the air in the high pressure system will flow "downhill" toward lower pressure, but the Cordillera mountains block the flow of air, channeling it through Chivela Pass in Mexico, the lake district of Nicaragua, and also Gaillard (Culebra) Cut in Panama. Many times, a Tehuano wind is followed by Papagayo and Panama winds a few days later as the high pressure system moves south. The arrival of these cold surges, and their associated anticyclonic circulation, strengthens the trade winds at low latitudes, and this effect can last for several days. The wind flow over Central America is actually composed of the confluence of two air streams; one from the north, associated with cold surges, and the other from the northeast, associated with trade winds north of

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the souther ...

Local effects

The winds blow at speeds of 80 km/h or more down the hillsides from Chivela Pass and over the waters of the Gulf of Tehuantepec, sometimes extending more than 500 miles (800 km) into the Pacific Ocean. The surface waters under the Gulf of Tehuantepec wind jet can cool by as much as 10 °C in a day. In addition to the cold water that is detectable from other satellite sensors, the ocean's response to these winds shows up in satellite estimates of chlorophyll from ocean color measurements. The cold water and high chlorophyll concentration are signatures of mixing and upwelling of cold, nutrient-rich deep water. Fish converge on this food source, which supports the highly successful fishing industry in the Gulf of Tehuantepec.

External links

*{{cite web , title=The Papagayo Wind , work=GES DAAC Ocean Color , url=http://disc.gsfc.nasa.gov/oceancolor/scifocus/oceanColor/papagayo.shtml , accessdate=March 6, 2006 , archive-url=https://web.archive.org/web/20060117183235/http://disc.gsfc.nasa.gov/oceancolor/scifocus/oceanColor/papagayo.shtml , archive-date=January 17, 2006 , url-status=dead Atmospheric dynamics Geography of Central America Mountains