Characteristics and Effects of Harmattan

The French military intervention in Libya in 2011 was codenamed Operation Harmattan, after the Harmattan wind in Africa.

In western Africa, November marks the arrival of the Harmattan―a north-easterly wind which originates due to the occurrence of a high pressure system over the central Sahara Desert, and blows from the Sahara into the Gulf of Guinea. Thus begins the arduous period of 3 - 4 months, marked by dry and dusty climate.

The origin of the word 'Harmattan' is difficult to trace. Most sources state that it has originated from the Akan cognate―Akan being a language spoken in Ghana and Suriname. The American Heritage Dictionary states that it may have come from the Arabic word haram, meaning something evil.

Basically, the Harmattan is a dry and dusty wind which forms as a result of the pressure gradient on the west coast of the continent of Africa, i.e., the Atlantic Coast. It is typically characterized by strong winds blowing from North to South from late November to mid-March, often clocking speeds of 1.76 m/s.

The Harmattan lowers the humidity to as low as 15 percent at times, and scatters clouds, thus hindering the formation of rainfall. Besides that, it is also characterized by fluctuation in ambient temperatures of the day and night, recording a drop to as low as 48°F at times.

As it blows over the Sahara, it collects fine dust and sand particles, which it carries along with it to the Gulf of Guinea, and further to the Cape Verde Islands in the Atlantic. Though rare, there have been instances wherein dust from the continent of Africa has been carried off to as far as the Americas by this wind.

The Harmattan brings dry and dusty air from the Sahara. The dust that it carries can result in the formation of haze, which can limit visibility and even block the Sun at times.

The hazy conditions in this region―referred to as the Harmattan haze―often results in the cancellation and diversion of several flights in western Africa, costing the aviation industry a loss of millions of dollars every year.

The Harmattan is known to create huge clouds of dust, which can intensify and result in the formation of full-fledged dust storms. Furthermore, if it comes in contact with monsoon―a seasonal wind in southern Asia, it can even trigger the formation of tornadoes.

There is no questioning the fact that it causes dramatic weather conditions, but its effects are not restricted to weather alone. This wind is a serious threat to the health of the people living in this region. For instance, when the humidity levels drop to as low as 15 percent, it is known to cause spontaneous nosebleeds in people.

As a result of the dust that is carried by this wind, many people suffer from frequent asthma attacks, respiratory tract infections, chest congestion, conjunctivitis, and other eye infections. Other health problems prevalent during the Harmattan season include fever, cold, flu, catarrh, cough, and headache.

The onset of the Harmattan season brings about conditions that are conducive for wildfires. Having said that, it's worth noting that most wildfires during the Harmattan season are caused when fires set intentionally to clear land goes out of hand as a result of human neglect. Wildfires fueled by this wind add to the already imposing threats associated with it, by resulting in loss of property and making breathing difficult.