atmospheric circulation

  By Edward Armstrong, University of Helsinki Algeria’s Tassili N’Ajjer plateau is Africa’s largest national park. Among its vast sandstone formations is perhaps the world’s largest art museum. Over 15,000 etchings and paintings are exhibited there, some as much as 11,000 years old according to scientific dating techniques, representing a unique ethnological and climatological record of the region. Curiously, however, these images do not depict the arid, barren landscape that […]