Sirocco

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Not to be confused with Socorro.
This article is about the Mediterranean wind. For other uses, see Sirocco (disambiguation) and Jugo (disambiguation).
The winds of the Mediterranean

Sirocco, scirocco, /sɪˈrɒk/, jugo or, rarely, siroc (Catalan: Xaloc, Greek: Σορόκος, Spanish: Siroco) is a Mediterranean wind that comes from the Sahara and reaches hurricane speeds in North Africa and Southern Europe.

Origin of name[edit]

A sirocco from Libya blowing dust over the Mediterranean, Malta, Italy, Croatia, Montenegro, Albania and Greece

Scirocco and Sirocco are from the Greek name, "σιρόκος" (sirokos),[1] while ghibli is its name in Libya. The name jugo, pronounced [jûɡo], used in Croatia, Montenegro, Serbia, Bosnia and Hercegovina, Macedonia, Slovenia, Slovakia, and, hot, dust-bearing wind is called la calima. In Albanian it is called jugu. The leveche usually carries red Sahara dust and is associated with storms and heavy rain, the wind being very strong, lasting about four days. In Portugal, it is known as siroco and xaroco. In Malta, it is known as xlokk.[2] In Levantine Arabic (Lebanon and Syria) a similar wind is referred to as شلوق shlūq.

Development[edit]

It arises from a warm, dry, tropical airmass that is pulled northward by low-pressure cells moving eastward across the Mediterranean Sea, with the wind originating in the Arabian or Sahara deserts.[3] 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.

Effects[edit]

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. Many people attribute health problems to the Sirocco either because of the heat and dust along the African coastal regions or because of the cool dampness 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 kilometres per hour are most common during the autumn and the spring. They reach a peak in March and in November when it is very hot, with a maximum speed of about 100 km/h (55 knots).

Combined with a rising tide, Sirocco is a factor responsible for the Acqua Alta phenomenon in the Venetian Lagoon.

Similar winds[edit]

Other prominent wind systems in the region are the bora/bura/burja (northwestern) and the llebeig/lebeccio/lebić (southwestern).

Calima[edit]

The Calima is a hot, oppressing dust and sand-laden, southerly to southeasterly, sometimes easterly wind in the Canary Islands region. It is particulary prevalent in winter. Like it's 'big brother' the Sirocco the calima blows out of a high-pressure over Northern Africa and the Sahara and is normally drawn northwards ahead of a passing cold-front or depression north of the archipelago. It's fine yellowish-brown dust is even creeping through doors and windows. Outside visibility often reduces to null.

Sometimes a rare small depression forming south-west of the Canary Islands increase wind-speed and intensity of a calima event. Such storms and the rising warm and humid air can lift dust 5,000 m or so above the Atlantic blanketing hundreds of thousands of square miles of the eastern Atlantic Ocean with a dense cloud of Saharan sand, many times reaching as far as the Caribbean.

This unnormal hot and humid calima is often associated with fog and patchy drizzle and the Canary people are heavily suffering from respiratory problems. Conditions could become even so bad that they might force public life and transport to a stand-still. On January 8, 2002, the international airport of Santa Cruz had to be closed because visibility dropped to less than 50 meters.

It has been shown that Saharan soil may have the potential of producing bioavailable iron when illuminated with visible light and also it has some essential macro and micro nutrient elements. In this study the impact of various growth media on development of some bread wheat (Triticum aestivum L.) and durum wheat (Triticum durum L.) cultivars have been investigated. As a four different nutrient media, Hewitt nutrient solution [1], illuminated and non-illuminated Saharan desert soil solutions and distilled water have been utilized. Shoot length (cm.seedling-1), leaf area (cm2 seedling-1) and photosynthetic pigments [chlorophyll a, chlorophyll b and carotenoids, mg ml-1 g fresh weight (g fw)-1] have been determined. The results of this study indicate that, wheat varieties fed by irradiated Saharan soil solution gave comparable results to Hewitt nutrient solution (Yücekutlu et al., 2011).

Yücekutlu A.N., Terzioğlu S., Saydam C. and Bildacı I., (2011. Organic Farming By Using Saharan. Soil: Could It Be An Alternative To Fertilizers? Hacettepe J. Biol. & Chem., 2011, 39 (1), 29–37.

See also[edit]

References[edit]

  1. ^ Glossary of Meteorology (2012-01-26). "Sirocco". American Meteorological Society. Retrieved 2014-03-31. 
  2. ^ Encyclopaedia Britannica. Scirocco/xlokk Retrieved on 2007-05-19.
  3. ^ Golden Gate Weather Services. Names of Winds. Retrieved on 2006-12-28.

External links[edit]