Tehuano wind
Encyclopedia
The Tehuano wind is a north to northeasterly wind which periodically blows across the Isthmus of Tehuantepec
in southern Mexico
. The wind is stronger than the trade wind
s which normally blow here. It is notable for causing a pronounced increase in upwelling
of cooler, nutrient-rich waters in the Gulf of Tehuantepec
on the Pacific coast
which in turn supports an abundance of sea life. The wind and upwelling are together referred to as a Tehuano event.
The Tehuano is caused by a surge of cooler, drier air originating from the North American continent. Such surges are more common in the winter, but may occur at other times of the year as well. This air is denser than the tropical air mass normally present in the region, thus a strong pressure gradient is established which induces the wind. The wind is further accelerated by the funneling effect of the Chivela Pass
between the Bay of Campeche
and the Pacific coastlines. The same conditions are the cause of the Papagayo wind
off the coast of Costa Rica and the Panama wind further south.
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, and prior to the opening of the Panama Canal was a major shipping route known simply as the Tehuantepec Route...
in southern Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
. The wind is stronger than the trade wind
Trade wind
The trade winds are the prevailing pattern of easterly surface winds found in the tropics, within the lower portion of the Earth's atmosphere, in the lower section of the troposphere near the Earth's equator...
s which normally blow here. It is notable for causing a pronounced increase in upwelling
Upwelling
Upwelling is an oceanographic phenomenon that involves wind-driven motion of dense, cooler, and usually nutrient-rich water towards the ocean surface, replacing the warmer, usually nutrient-depleted surface water. The increased availability in upwelling regions results in high levels of primary...
of cooler, nutrient-rich waters in the Gulf of Tehuantepec
Gulf of Tehuantepec
Gulf of Tehuantepec is a large body of water on the Pacific coast of the Isthmus of Tehuantepec, southeastern Mexico, at . Most of the hurricanes that form in the Eastern Pacific organize in or near this body of water...
on the Pacific coast
Pacific Coast
A country's Pacific coast is the part of its coast bordering the Pacific Ocean.-The Americas:Countries on the western side of the Americas have a Pacific coast as their western border.* Geography of Canada* Geography of Chile* Geography of Colombia...
which in turn supports an abundance of sea life. The wind and upwelling are together referred to as a Tehuano event.
The Tehuano is caused by a surge of cooler, drier air originating from the North American continent. Such surges are more common in the winter, but may occur at other times of the year as well. This air is denser than the tropical air mass normally present in the region, thus a strong pressure gradient is established which induces the wind. The wind is further accelerated by the funneling effect of the Chivela Pass
Chivela Pass
The Chivela Pass is a narrow mountain pass in the Sierra Madre Mountains that funnels cooler drier air from the North American continent, through southern Mexico, into the Pacific...
between the Bay of Campeche
Bay of Campeche
The Bay of Campeche is the southern bight of the Gulf of Mexico. It is surrounded on three sides by the Mexican states of Campeche, Tabasco and Veracruz. It was named by Francisco Hernández de Córdoba and Antonio de Alaminos during their expedition in 1517...
and the Pacific coastlines. The same conditions are the cause of the Papagayo wind
Papagayo wind
The Papagayo wind is a north to northeasterly wind which periodically blows through the gap in the mountain ranges of Central America in which Lake Nicaragua is located. It is named for the Gulf of Papagayo on the Pacific coast in this region. The wind is stronger than the trade winds which...
off the coast of Costa Rica and the Panama wind further south.