The winds of the Mediterranean |
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Sirocco ( /sɪˈrɒkoʊ/ sih-RO-koh), scirocco, or, rarely, siroc (see § Names below) is a Mediterranean wind that comes from the Sahara and can reach hurricane speeds in North Africa and Southern Europe, especially during the summer season.
Sirocco derives from šurūq (Arabic : شروق), verbal noun of šaraqa , related to the East, aš-šarq. Various names for this wind in other languages include:
Siroccos arise from warm, dry, tropical air masses that are pulled northward by low-pressure cells moving eastward across the Mediterranean Sea, with the wind originating in the Arabian or Sahara deserts. [1] The hotter, drier continental air mixes with the cooler, wetter air of the maritime cyclone, and the counter-clockwise circulation of the low propels the mixed air across the southern coasts of Europe.
The sirocco causes dusty dry conditions along the northern coast of Africa, storms in the Mediterranean Sea, and cool wet weather in Europe. The sirocco's duration may be as short as half a day or may last several days. While passing over the Mediterranean Sea, the sirocco picks up moisture; this results in rainfall in the southern part of Italy, known locally as "blood rain" due to the red sand mixed with the falling rain.
Sirocco is commonly perceived as causing unease and an irritable mood in people. [2] In addition, many people attribute health problems to the wind, either because of the heat and dust brought from African coastal regions, or because of the cool dampness further north in Europe. The dust within the sirocco winds can cause abrasion in mechanical devices and penetrate buildings.
Sirocco winds with speeds of up to 100 km/h (62 mph; 54 kn) are most common during autumn and spring. They reach a peak in March and in November when it is very hot.
When combined with a rising tide, the sirocco can cause the acqua alta phenomenon in the Venetian Lagoon.
This wind also has an impact on fishing. For example, the anchovies caught in the Gulf of Trieste near Barcola, which are in great demand as a delicacy, are only caught in Sirocco. In cold winds, like the bora, the fish disappear into the vastness of the Adriatic. [3]
Nigeria is a country in West Africa, it shares land borders with the Republic of Benin to the west, Chad and Cameroon to the east, and Niger to the north. Its coast lies on the Gulf of Guinea in the south and it borders Lake Chad to the northeast. Notable geographical features in Nigeria include the Adamawa Plateau, Mambilla Plateau, Jos Plateau, Obudu Plateau, the Niger River, Benue River, and Niger Delta.
A monsoon is traditionally a seasonal reversing wind accompanied by corresponding changes in precipitation but is now used to describe seasonal changes in atmospheric circulation and precipitation associated with annual latitudinal oscillation of the Intertropical Convergence Zone between its limits to the north and south of the equator. Usually, the term monsoon is used to refer to the rainy phase of a seasonally changing pattern, although technically there is also a dry phase. The term is also sometimes used to describe locally heavy but short-term rains.
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.
The mistral is a strong, cold, northwesterly wind that blows from southern France into the Gulf of Lion in the northern Mediterranean. It produces sustained winds often exceeding 66 km/h, sometimes reaching 185 km/h. It is most common in the winter and spring, and strongest in the transition between the two seasons. Periods of the wind exceeding 30 km/h for more than sixty-five hours have been reported.
The Sahara is a desert on the African continent. With an area of 9,200,000 square kilometres (3,600,000 sq mi), it is the largest hot desert in the world and the third-largest desert overall, smaller only than the deserts of Antarctica and the northern Arctic.
Orographic lift occurs when an air mass is forced from a low elevation to a higher elevation as it moves over rising terrain. As the air mass gains altitude it quickly cools down adiabatically, which can raise the relative humidity to 100% and create clouds and, under the right conditions, precipitation.
Southern Europe is the southern region of Europe. It is also known as Mediterranean Europe, as its geography is essentially marked by the Mediterranean Sea. Definitions of Southern Europe include some or all of these countries and regions: Albania, Andorra, Bosnia and Herzegovina, Bulgaria, Croatia, Cyprus, Turkey, Gibraltar, Greece, Italy, Kosovo, Malta, Monaco, Montenegro, North Macedonia, Portugal, Romania, San Marino, Serbia, Slovenia, Southern France, Spain, and Vatican City.
A rain shadow is an area of significantly reduced rainfall behind a mountainous region, on the side facing away from prevailing winds, known as its leeward side.
A haboob is a type of intense dust storm carried on an atmospheric gravity current, also known as a weather front. Haboobs occur regularly in dry land area regions throughout 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.
Berg wind is the South African name for a katabatic wind: a hot dry wind blowing down the Great Escarpment from the high central plateau to the coast.
The Sahara pump theory is a hypothesis that explains how flora and fauna migrated between Eurasia and Africa via a land bridge in the Levant region. It posits that extended periods of abundant rainfall lasting many thousands of years in Africa are associated with a "wet-green Sahara" phase, during which larger lakes and more rivers existed. This caused changes in the flora and fauna found in the area. Migration along the river corridor was halted when, during a desert phase 1.8–0.8 million years ago (mya), the Nile ceased to flow completely and possibly flowed only temporarily in other periods due to the geologic uplift of the Nile River region.
Severe weather is any dangerous meteorological phenomenon with the potential to cause damage, serious social disruption, or loss of human life. Types of severe weather phenomena vary, depending on the latitude, altitude, topography, and atmospheric conditions. High winds, hail, excessive precipitation, and wildfires are forms and effects of severe weather, as are thunderstorms, downbursts, tornadoes, waterspouts, tropical cyclones, and extratropical cyclones. Regional and seasonal severe weather phenomena include blizzards (snowstorms), ice storms, and duststorms. Extreme weather phenomena which cause extreme heat, cold, wetness or drought often will bring severe weather events. One of the principal effects of anthropogenic climate change is changes in severe and extreme weather patterns.
Rain is water droplets that have condensed from atmospheric water vapor and then fall under gravity. Rain is a major component of the water cycle and is responsible for depositing most of the fresh water on the Earth. It provides water for hydroelectric power plants, crop irrigation, and suitable conditions for many types of ecosystems.
The lodos is the strong south-westerly wind which may predominate episodically in the Aegean Sea and Marmara Sea as well as the Mediterranean coast of Turkey all the year round; it frequently raises high seas and may give violent westerly squalls. The word lodos is Turkish, coming from Greek word "Notus", and originally means "southern wind".
Rain dust or snow dust, traditionally known as muddy rain, red rain, or coloured rain, is a variety of rain which contains enough desert dust for the dust to be visible without using a microscope.
The chergui or sharqi is the name of a continental easterly or southeasterly wind which blows on the southernmost part of Morocco, a hot and dry wind coming from the Sahara Desert. This wind can be compared with the sirocco, a very hot and very dry desert wind. The Arabic word means "coming from the east", as the chergui emanates from the desert east of the Atlas Mountains. This is a rain shadow wind as it falls down after passing over the top of the mountain range as a very hot and dry air into the coastal plains area towards the Atlantic ocean, which brings soaring temperatures typical of the desert, often over 40 °C (104 °F) and can even turn around 48 °C (118.4 °F) during the day at summertime and the relative humidity is extremely low, nearly always below 15%. The chergui can also more rarely blow at wintertime, and is responsible of a warm, sunny and dry weather.
Khamsin, chamsin or hamsin, more commonly known in Egypt as khamaseen, is a dry, hot, sandy local wind affecting Egypt and the Levant; similar winds, blowing in other parts of North Africa, the Arabian Peninsula and the entire Mediterranean basin, have different local names, such as bad-i-sad-o-bist roz in Iran and Afghanistan, haboob in the Sudan, aajej in southern Morocco, ghibli in Tunis, harmattan in the western Maghreb, africo in Italy, sirocco which blows in winter over much of the Middle East, and simoom.
This glossary of meteorology is a list of terms and concepts relevant to meteorology and atmospheric science, their sub-disciplines, and related fields.