Dunes in the Sahara--Students from the Region

The second half of the fall semester is starting, and I'm teaching three modules.  Most "courses" run only part of the semester.  I'm teaching two modules to the geology master's students, and one to the master's students at CRASTE-LF.  There are about 20 students in each group, and they attend essentially all their course work together.  The geology students are almost all from Morocco, but about half of the CRASTE-LF students are from 10 other countries.

An example I have often used in my research and teaching involves a region in the south central Sahara where two orthogonal sets of dunes intersect.  I have been looking at automatically extracting worldwide dune characteristics from digital elevation models, and this region jumped out for it unusual characteristics.  I have always attributed this to shifting seasonal wind patterns, shown in the bottom two maps.  

For US students, this area is a long ways from nowhere.  Here I have a student who is from "near" here.  I put "near" in quotation marks because these landlocked countries are huge, and the population density in these regions is very low.

Dunes trending NE-SW in the top and bottom of the map, and NW-SE in the center.  Location shown by the red box in the center of the next two maps.

Average January wind patterns.

Average July wind patterns.

Night lights in NW Africa, with national borders.  The coastal cities stand out with bright white, with the Sahara a barren black with a belt from Mauritania, Mali, Niger, Chad, and Sudan having no people or no electricity (or very little of both.