Calima or Kalima is a term used to describe a meteorological phenomenon that occurs when fine sand and dust particles from the Sahara Desert are lifted into the atmosphere and transported by prevailing winds.
It usually happens in the summer and lasts 3-5 days. [1]
The primary cause of Kalima is the movement of air masses over the Sahara Desert. [2] The region near the surface in the Sahara undergoes strong warming through heat transfer from the underlying layer. This extreme diurnal warming creates instability in the lowest layer of the atmosphere, warming and drying the air near the surface and cooling while humidifying the air near the top of the layer through convective mixing. [3]
The desert's arid environment causes the soil to become fine and easily lifted by strong winds, such as those associated with the Harmattan or the trade winds. These winds can lift millions of tons of sand and dust into the atmosphere, creating a dense, suspended cloud that can travel thousands of kilometers. [4] Some of clouds of sand reach up to 6,000 meters in altitude. The raised dust can then move in the eastward atmospheric circulation while being captured above a marine inversion as it passes over the ocean, reaching the Canary Islands. [3]
The humid air in the inversion layer is often associated with fog or drizzle covering the Canary Islands. The dust particles that settle also cause respiratory problems, especially for people with pre-existing respiratory conditions. [5] It is therefore, best for people to wear respiratory masks if they have to go outdoors when there is Calima.
Aside from affecting people's health, when there is Kalima, weather conditions can become very poor and force the suspension of some public services, including transportation. For example, on January 8, 2002, the Santa Cruz International Airport had to be closed because visibility fell to less than 50 meters. [6]
In 2020 the wind spread three wildfires, forcing about 2,000 residents to evacuate in Tenerife and Gran Canaria. [7] Gran Canaria had the worst air quality in the world that weekend due to the dust, with about 40 times the particle density considered safe by the World Health Organization. [8] This resulted in 745 flights being canceled and 84 others diverting to different airports. [8]
The Canary Islands, also known informally as the Canaries, are a Spanish autonomous community and archipelago in Macaronesia in the Atlantic Ocean. At their closest point to the African mainland, they are 100 kilometres west of Morocco and the Western Sahara. They are the southernmost of the autonomous communities of Spain. The islands have a population of 2.2 million people and are the most populous special territory of the European Union.
Fuerteventura is one of the Canary Islands, in the Atlantic Ocean, geographically part of Macaronesia, and politically part of Spain. It is located 97 km (60 mi) away from the coast of North Africa. The island was declared a biosphere reserve by UNESCO in 2009.
A dust devil is a strong, well-formed, and relatively short-lived whirlwind. Its size ranges from small to large. The primary vertical motion is upward. Dust devils are usually harmless, but can on rare occasions grow large enough to pose a threat to both people and property.
Fog is a visible aerosol consisting of tiny water droplets or ice crystals suspended in the air at or near the Earth's surface. Fog can be considered a type of low-lying cloud usually resembling stratus, and is heavily influenced by nearby bodies of water, topography, and wind conditions. In turn, fog affects many human activities, such as shipping, travel, and warfare.
A dust storm, also called a sandstorm, 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. Fine particles are transported by saltation and suspension, a process that moves soil from one place and deposits it in another.
Dust is made of fine particles of solid matter. On Earth, it generally consists of particles in the atmosphere that come from various sources such as soil lifted by wind, volcanic eruptions, and pollution. Dust in homes is composed of about 20–50% dead skin cells. The rest, and in offices and other built environments, is composed of small amounts of plant pollen, human hairs, animal fur, textile fibers, paper fibers, minerals from outdoor soil, burnt meteorite particles, and many other materials which may be found in the local environment.
Teide, or Mount Teide, is a volcano on Tenerife in the Canary Islands, Spain. Its summit is the highest point in Spain and the highest point above sea level in the islands of the Atlantic. If measured from the ocean floor, its height of 7,500 m (24,600 ft) makes Teide the third-highest volcano in the world, and is described by UNESCO and NASA as Earth's third-tallest volcanic structure. Teide's elevation above sea level makes Tenerife the tenth highest island in the world.
Aeolian processes, also spelled eolian, pertain to wind activity in the study of geology and weather and specifically to the wind's ability to shape the surface of the Earth. Winds may erode, transport, and deposit materials and are effective agents in regions with sparse vegetation, a lack of soil moisture and a large supply of unconsolidated sediments. Although water is a much more powerful eroding force than wind, aeolian processes are important in arid environments such as deserts.
The Harmattan is a season in West Africa that occurs between the end of November and the middle of March. It is characterized by the dry and dusty northeasterly trade wind, of the same name, which blows from the Sahara over West Africa into the Gulf of Guinea. The name is related to the word haramata in the Twi language. The temperature is cold mostly at night in some places but can be very hot in certain places during daytime. generally, temperature differences can also depend on local circumstances.
Binter Canarias S.A. is the flag carrier of the Spanish autonomous community of the Canary Islands, based on the grounds of Gran Canaria Airport in Telde, Gran Canaria and Tenerife North Airport, San Cristóbal de La Laguna, Spain. It is a regional air carrier operating inter-island services within the Canary Islands, and other Atlantic islands, it also operates to the Spanish Mainland and some European destinations, mainly in France and Italy. Affiliated airlines operate on behalf of Binter in services to Morocco, Mainland-Spain, Portugal and Western Sahara.
Gran Canaria Airport is a passenger and freight airport on the island of Gran Canaria. It is an important airport within the Spanish air-transport network, as it holds the sixth position in terms of passengers, and fifth in terms of operations and cargo transported. It also ranks first of the Canary Islands in all three categories, although the island of Tenerife has higher passenger numbers overall if statistics from the two airports located on the island are combined. The facility covers 553 hectares of land and contains two 3,100m runways.
A shamal is a northwesterly wind blowing over Iraq and the Persian Gulf states, often strong during the day, but decreasing at night. This weather effect occurs from once to several times a year, mostly in summer, but sometimes in winter. The resulting wind typically creates large sandstorms that impact Iraq, most sand having been picked up from Jordan and Syria.
In geology, saltation is a specific type of particle transport by fluids such as wind or water. It occurs when loose materials are removed from a bed and carried by the fluid, before being transported back to the surface. Examples include pebble transport by rivers, sand drift over desert surfaces, soil blowing over fields, and snow drift over smooth surfaces such as those in the Arctic or Canadian Prairies.
The Saharan air layer (SAL) is an extremely hot, dry, and sometimes dust-laden layer of the atmosphere that often overlies the cooler, more humid surface air of the Atlantic Ocean. It carries upwards of 60 million tonnes of dust annually over the ocean and the Americas. This annual phenomenon sometimes cools the ocean and suppresses Atlantic tropical cyclogenesis.
Mineral dust is atmospheric aerosol originated from the suspension of minerals constituting the soil, composed of various oxides and carbonates. Human activities lead to 30% of the airborne dust (particulates) load in the atmosphere. The Sahara Desert is the major source of mineral dust, which subsequently spreads across the Mediterranean and Caribbean seas into northern South America, Central America, and eastern North America, and Europe. Additionally, it plays a significant role in the nutrient inflow to the Amazon rainforest. The Gobi Desert is another source of dust in the atmosphere, which affects eastern Asia and western North America.
Navegacion y Servicios Aéreos Canarios, better known by its initialism NAYSA, was a regional airline based in Las Palmas, Gran Canaria, Spain. It operated scheduled and charter flights, as well as cargo flights, air taxis, air ambulance flights and crew transfers. Its main base was Gran Canaria International Airport.
Coniology or koniology is the study of atmospheric dust and its effects. Samples of dust are often collected by a device called a coniometer. Coniology refers to the observation and contemplation of dust in an atmosphere, but the study of dust may also be applied to dust in space, therefore connecting it to a variety of atmospheric and extraterrestrial topics.
Wind is the natural movement of air or other gases relative to a planet's surface. Winds occur on a range of scales, from thunderstorm flows lasting tens of minutes, to local breezes generated by heating of land surfaces and lasting a few hours, to global winds resulting from the difference in absorption of solar energy between the climate zones on Earth. The two main causes of large-scale atmospheric circulation are the differential heating between the equator and the poles, and the rotation of the planet. Within the tropics and subtropics, thermal low circulations over terrain and high plateaus can drive monsoon circulations. In coastal areas the sea breeze/land breeze cycle can define local winds; in areas that have variable terrain, mountain and valley breezes can prevail.
A desert is a landscape where little precipitation occurs and, consequently, living conditions create unique biomes and ecosystems. The lack of vegetation exposes the unprotected surface of the ground to denudation. About one-third of the land surface of the Earth is arid or semi-arid. This includes much of the polar regions, where little precipitation occurs, and which are sometimes called polar deserts or "cold deserts". Deserts can be classified by the amount of precipitation that falls, by the temperature that prevails, by the causes of desertification or by their geographical location.
Saharan dust is an aeolian mineral dust from the Sahara desert, the largest hot desert in the world. The desert spans just over 9 million square kilometers, from the Atlantic Ocean to the Red Sea, from the Mediterranean sea to the Niger River valley and the Sudan region in the south.