Haboob
Encyclopedia
A haboob is a type of intense duststorm
carried on an atmospheric gravity current
. Haboobs are regularly observed in arid regions throughout the world. They have been observed in the Sahara desert (typically Sudan
, where they were named and described), as well as across the Arabian Peninsula
, throughout Kuwait
, and in the most arid regions of Iraq
. African haboobs result from the northward summer shift of the inter-tropical front into North Africa
, bringing moisture from the Gulf of Guinea
. Haboob wind
s in the Arabian Peninsula, Iraq, Kuwait, and North America are frequently created by the collapse of a thunderstorm
, while haboobs in Australia may be frequently associated with cold front
s. The deserts of Central Australia
, especially near Alice Springs, are particularly prone to Haboobs with the sand and debris reaching several kilometers into the sky and leaving up to a foot of sand covering everything in its path. The arid and semiarid regions of North America
– in fact, any dryland region – may experience haboobs. In the USA, they are frequently observed in the deserts of Arizona
, including Yuma
and Phoenix
, as well as New Mexico
and Texas
. During thunderstorm formation, winds move in a direction opposite to the storm's travel, and they will move from all directions into the thunderstorm. When the storm collapses and begins to release precipitation, wind directions reverse, gusting outward from the storm and generally gusting the strongest in the direction of the storm's travel.
When this downdraft, or "downburst
", reaches the ground, dry, loose sand from the desert settings is essentially blown up, creating a wall of sediment preceding the storm cloud. This wall of sand can be up to 100 km (62.1 mi) wide and several kilometers in elevation. At their strongest, haboob winds can often travel at 35–100 km/h (~20–60 mph), and they may approach with little to no warning. Often rain is not seen at the ground level as it evaporates in the hot, dry air (a phenomenon known as virga
), though on occasion when the rain does persist, the precipitation can contain a considerable quantity of dust (severe cases called "mud storms"). Eye and respiratory system protection are advisable for anyone who must be outside during a haboob—moving to a place of shelter is highly desirable during a strong event.
Dust storm
A dust / sand storm is a meteorological phenomenon common in arid and semi-arid regions. Dust storms arise when a gust front or other strong wind blows loose sand and dirt from a dry surface. Particles are transported by saltation and suspension, causing soil to move from one place and deposition...
carried on an atmospheric gravity current
Gravity current
In fluid dynamics, a gravity current is a primarily horizontal flow in a gravitational field that is driven by a density difference, hence gravity currents also sometimes being referred to as "density currents"...
. Haboobs are regularly observed in arid regions throughout the world. They have been observed in the Sahara desert (typically Sudan
Sudan
Sudan , officially the Republic of the Sudan , is a country in North Africa, sometimes considered part of the Middle East politically. It is bordered by Egypt to the north, the Red Sea to the northeast, Eritrea and Ethiopia to the east, South Sudan to the south, the Central African Republic to the...
, where they were named and described), as well as across the Arabian Peninsula
Arabian Peninsula
The Arabian Peninsula is a land mass situated north-east of Africa. Also known as Arabia or the Arabian subcontinent, it is the world's largest peninsula and covers 3,237,500 km2...
, throughout Kuwait
Kuwait
The State of Kuwait is a sovereign Arab state situated in the north-east of the Arabian Peninsula in Western Asia. It is bordered by Saudi Arabia to the south at Khafji, and Iraq to the north at Basra. It lies on the north-western shore of the Persian Gulf. The name Kuwait is derived from the...
, and in the most arid regions of Iraq
Iraq
Iraq ; officially the Republic of Iraq is a country in Western Asia spanning most of the northwestern end of the Zagros mountain range, the eastern part of the Syrian Desert and the northern part of the Arabian Desert....
. African haboobs result from the northward summer shift of the inter-tropical front into North Africa
North Africa
North Africa or Northern Africa is the northernmost region of the African continent, linked by the Sahara to Sub-Saharan Africa. Geopolitically, the United Nations definition of Northern Africa includes eight countries or territories; Algeria, Egypt, Libya, Morocco, South Sudan, Sudan, Tunisia, and...
, bringing moisture from the Gulf of Guinea
Gulf of Guinea
The Gulf of Guinea is the northeasternmost part of the tropical Atlantic Ocean between Cape Lopez in Gabon, north and west to Cape Palmas in Liberia. The intersection of the Equator and Prime Meridian is in the gulf....
. Haboob wind
Wind
Wind is the flow of gases on a large scale. On Earth, wind consists of the bulk movement of air. In outer space, solar wind is the movement of gases or charged particles from the sun through space, while planetary wind is the outgassing of light chemical elements from a planet's atmosphere into space...
s in the Arabian Peninsula, Iraq, Kuwait, and North America are frequently created by the collapse of a thunderstorm
Thunderstorm
A thunderstorm, also known as an electrical storm, a lightning storm, thundershower or simply a storm is a form of weather characterized by the presence of lightning and its acoustic effect on the Earth's atmosphere known as thunder. The meteorologically assigned cloud type associated with the...
, while haboobs in Australia may be frequently associated with cold front
Cold front
A cold front is defined as the leading edge of a cooler mass of air, replacing a warmer mass of air.-Development of cold front:The cooler and denser air wedges under the less-dense warmer air, lifting it...
s. The deserts of Central Australia
Central Australia
Central Australia/Alice Springs Region is one of the five regions in the Northern Territory. The term Central Australia is used to describe an area centred on Alice Springs in Australia. It is sometimes referred to as Centralia; likewise the people of the area are sometimes called Centralians...
, especially near Alice Springs, are particularly prone to Haboobs with the sand and debris reaching several kilometers into the sky and leaving up to a foot of sand covering everything in its path. The arid and semiarid regions of North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
– in fact, any dryland region – may experience haboobs. In the USA, they are frequently observed in the deserts of Arizona
Arizona
Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...
, including Yuma
Yuma, Arizona
Yuma is a city in and the county seat of Yuma County, Arizona, United States. It is located in the southwestern corner of the state, and the population of the city was 77,515 at the 2000 census, with a 2008 Census Bureau estimated population of 90,041....
and Phoenix
Phoenix, Arizona
Phoenix is the capital, and largest city, of the U.S. state of Arizona, as well as the sixth most populated city in the United States. Phoenix is home to 1,445,632 people according to the official 2010 U.S. Census Bureau data...
, as well as New Mexico
New Mexico
New Mexico is a state located in the southwest and western regions of the United States. New Mexico is also usually considered one of the Mountain States. With a population density of 16 per square mile, New Mexico is the sixth-most sparsely inhabited U.S...
and Texas
Texas
Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...
. During thunderstorm formation, winds move in a direction opposite to the storm's travel, and they will move from all directions into the thunderstorm. When the storm collapses and begins to release precipitation, wind directions reverse, gusting outward from the storm and generally gusting the strongest in the direction of the storm's travel.
When this downdraft, or "downburst
Downburst
A downburst is created by an area of significantly rain-cooled air that, after reaching ground level, spreads out in all directions producing strong winds. Unlike winds in a tornado, winds in a downburst are directed outwards from the point where it hits land or water...
", reaches the ground, dry, loose sand from the desert settings is essentially blown up, creating a wall of sediment preceding the storm cloud. This wall of sand can be up to 100 km (62.1 mi) wide and several kilometers in elevation. At their strongest, haboob winds can often travel at 35–100 km/h (~20–60 mph), and they may approach with little to no warning. Often rain is not seen at the ground level as it evaporates in the hot, dry air (a phenomenon known as virga
Virga
In meteorology, virga is an observable streak or shaft of precipitation that falls from a cloud but evaporates before reaching the ground. At high altitudes the precipitation falls mainly as ice crystals before melting and finally evaporating; this is usually due to compressional heating, because...
), though on occasion when the rain does persist, the precipitation can contain a considerable quantity of dust (severe cases called "mud storms"). Eye and respiratory system protection are advisable for anyone who must be outside during a haboob—moving to a place of shelter is highly desirable during a strong event.
See also
- Bora (wind)Bora (wind)Bora or Bura is a northern to north-eastern katabatic wind in the Adriatic, Bosnia and Herzegovina, Croatia, Montenegro, Italy, Greece, Slovenia, and Turkey....
- Dry thunderstormDry thunderstormA dry thunderstorm is a thunderstorm that produces thunder and lightning, but most or all of its precipitation evaporates before reaching the ground.-Where dry thunderstorms occur:...
- Dust devilDust devilA dust devil is a strong, well-formed, and relatively long-lived whirlwind, ranging from small to large . The primary vertical motion is upward...
- Dust stormDust stormA dust / sand storm is a meteorological phenomenon common in arid and semi-arid regions. Dust storms arise when a gust front or other strong wind blows loose sand and dirt from a dry surface. Particles are transported by saltation and suspension, causing soil to move from one place and deposition...
- Intertropical Convergence ZoneIntertropical Convergence ZoneThe Intertropical Convergence Zone , known by sailors as The Doldrums, is the area encircling the earth near the equator where winds originating in the northern and southern hemispheres come together....
- KhamsinKhamsinKhamsin, khamseen, chamsin or hamsin , also known as khamaseen refers to a dry, hot and dusty local wind blowing in North Africa and the Arabian Peninsula. Similar winds in the area are sirocco and simoom...
- Mistral (wind)Mistral (wind)The mistral is a strong, cold and usually dry regional wind in France, coming from the north or northwest, which accelerates when it passes through the valleys of the Rhone and the Durance Rivers to the coast of the Mediterranean around the Camargue region. It affects the northeast of the plain...
- Outflow boundaryOutflow boundaryAn outflow boundary, also known as a gust front, is a storm-scale or mesoscale boundary separating thunderstorm-cooled air from the surrounding air; similar in effect to a cold front, with passage marked by a wind shift and usually a drop in temperature and a related pressure jump...
- SimoomSimoomSimoom is a strong, dry, dust-laden local wind that blows in the Sahara, Palestine, Israel, Jordan, Syria, and the deserts of Arabian Peninsula. Alternative spellings include samiel, sameyel, samoon, samun, simoun, and simoon...
- SiroccoSiroccoSirocco, scirocco, , jugo or, rarely, siroc is a Mediterranean wind that comes from the Sahara and reaches hurricane speeds in North Africa and Southern Europe. It is known in North Africa by the Arabic word qibli or ghibli Sirocco, scirocco, , jugo or, rarely, siroc is a Mediterranean wind...
External links
- Haboob Photos @ HikeArizona.COM
- Haboobs, Arizona Department of Transportation.
- The Bibliography of Aeolian Research
- Haboob on Winds of the World
- Short Video of the 5 July 2011 Arizona Haboob (Flash Video software or a web browser supporting H.264/MPEG-4 AVC is necessary to see the content)
- Time-lapse video of the 5 July 2011 Arizona Haboob