 
 <prompt> Wetin be di diffrence between di systems? Based on di previous question, write one context wey get di answer. E fit be 1 - 20 sentences. Context: <response>: The effects of local surface low pressure dey very limited because upper-level subsidence still dey block any form of air ascent. Also, to dey protected against rain-bearing weather systems by the atmospheric circulation itself, the desert dey even drier because of im geographical configuration and location. Indeed, the extreme aridity of the Sahara no fit only explain by the subtropical high pressure. The Atlas Mountains, wey dey Algeria, Morocco and Tunisia also dey help to enhance the aridity of the northern part of the desert. These major mountain ranges dey act as barrier wey dey cause strong rain shadow effect for the leeward side by dropping much of the humidity wey atmospheric disturbances along the polar front bring, wey dey affect the surrounding Mediterranean climates. 