Climate of the Mediterranean and North Africa
This is an advance summary of a forthcoming article in the Oxford Research Encyclopedia of Climate Science. Please check back later for the full article.
The Mediterranean is a closed sea limited by Europe to the north, Asia to the east, and Africa to the south. It covers an area of circa 2.5 million km2 between 30 °N and 46 °N latitude and 6 °W and 36 °E longitude. The term Mediterranean climate is applied beyond the Mediterranean region itself and has been used since the early 20th century to classify other regions of the world, such as California or South Africa, usually located in the 30º to 40º latitudinal band. The Mediterranean climate can be broadly characterized by warm to hot dry summers and mild wet winters. However, this broad picture hides important differences that can be explained through the existence of two geographical gradients: North/South, with a warmer and drier south, and West/East, more influenced by Atlantic/Asian circulation.
The region is located on a crossroad between the midlatitudes and the subtropical regimes. Thus, small changes in the Atlantic storm track may lead to dramatic changes in the precipitation of the North-Western area of the basin. The variability of the descending northern branch of the Hadley cell influences the climate of the southern margin. On the other hand, the eastern border climate is conditioned by the Siberian High in winter and the Indian Summer Monsoon during summer. All these large-scale factors are modulated by the complex orography of the region, which is almost completely surrounded by steep mountains, the contrasting albedo, and the moisture supplied by the Mediterranean Sea. The interactions occurring among all these factors lead to a complex picture with some relevant phenomena characteristic of the Mediterranean region, such as heat waves, water stress and droughts, Saharan dust intrusions, or specific types of cyclogenesis.
Climate model projections generally agree in characterizing the region as a climate change hotspot, considering that it is one of the areas likely to suffer one of the most pronounced climate changes in the globe. However, this anthropogenic influence is not new, since the region is densely populated and is the home of some the oldest civilizations on Earth. This has produced multiple and continuous modifications in the land cover with a relevant impact on climate, which can be traced from the rich available documentary evidence and high-resolution natural proxies.