Read at : Google Alert – desertification
Late dust storm covers Nigeria
By JON GAMBRELL (AP) –
LAGOS, Nigeria — The yellow haze descended across Nigeria, blotting out the sun, canceling airline flights and coating everything with a fine layer of dust.
The sudden storm sparked frightened text messages about supposedly killer acid rain, but meteorologists say the weather comes from the harmattan, a yearly trade wind that brings dust from the Sahara Desert through Nigeria and the rest of West Africa. This year, however, the harmattan has come at an abnormal time, a possible result of global warming. Experts say it may delay the rainy season in Africa’s most populous nation and there are worries it may even throw off future seasonal changes.
“It is part of the changes of the climate,” said Temi Ologunorisa, a professor of climatology at Osun State University. “With the coming of this dust, you cannot have rain.”
The harmattan, caused by shifting weather patterns, means “tears your breath apart” in Twi, a West African language. The harmattan season typically begins in late November, as Nigeria’s dry season begins to end. The winds carry the sands and dust of the Sahara southward, and pick up the loose crop soil of Nigeria’s arid northern Sahel with it.
This year, the harmattan briefly appeared in January. It typically ends by February, said Sampson Wilson, a deputy general manager at the government-run Nigerian Meteorological Agency. But it blew back into Nigeria without warning last weekend, first enveloping the country’s north in dust and dropping visibility to almost zero, according to Wilson, and forcing many airlines to cancel flights in the country of 150 million people.
As it reached south, the storm encased the megacity of Lagos in a yellow fog that made the setting sun give off no more light than the moon.
Northern Nigeria is experiencing growing desertification as rising temperatures allow the edge of the Sahara Desert to creep closer to the country. That additional dust adds fuel for the harmattan winds, said Ologunorisa, an expert on climate change.