Context: The effects of local surface low pressure are extremely limited because upper-level subsidence still continues to block any form of air ascent. Also, to be protected against rain-bearing weather systems by the atmospheric circulation itself, the desert is made even drier by his geographical configuration and location. Indeed, the extreme aridity of the Sahara can't be only explained by the subtropical high pressure. The Atlas Mountains, found in Algeria, Morocco and Tunisia also help to enhance the aridity of the northern part of the desert. These major mountain ranges act as a barrier causing a strong rain shadow effect on the leeward side by dropping much of the humidity brought by atmospheric disturbances along the polar front which affects the surrounding Mediterranean climates.

Question: What is blocked due to local surface low pressure?
Answer: air ascent

Question: What mountain helps enhance the aridity of the desert?
Answer: Atlas Mountains

Question: Where are the Atlas Mountains located?
Answer: Algeria

Question: what is blocked buy the surface low pressure?
Answer: Unanswerable

Question: what contributes to the moisture that is present in the desert?
Answer: Unanswerable

Question: what is explained by the subtropical low-pressure?
Answer: Unanswerable

Question: What mountains reduce some of the aridity?
Answer: Unanswerable

Question: What is the sole cause of extreme aridity in the Sahara?
Answer: Unanswerable

Question: Where is the Sahara located?
Answer: Unanswerable

Question: What mountain range is located in the Sahara?
Answer: Unanswerable

Question: What limits the effects of the mountains?
Answer: Unanswerable

Question: What is to the north of the Atlas Mountains?
Answer: Unanswerable