Sand, sand and more sand

Deserts are physical phenomena that I have never really studied, apart from a brief overview in my Geology A-Level and seeing as though estimates show that they cover between 14-18% of the Earth's land surface, I thought it'd be wise to broaden my knowledge regarding them.

It is clear that deserts are intimately linked with other physical geography topics such as climate. Their formation is directly influenced by the circulation patterns that occur between the tropics. Subtropical areas typically have constant high atmospheric pressure due to the descending air of the Hadley cells. These conditions prevent moisture bearing clouds from forming and therefore lead to dry, arid conditions. The short video below provides a very simplified version of this.

http://www.youtube.com/watch?v=DHrapzHPCSA&feature=related

Whilst teaching it will be important to ensure that pupils are aware that the term 'desert' is not restricted to hot, arid areas such as the Sahara. Some scientists argue that large tundra areas such as the Antarctic can also be classified as deserts as they receive very small amounts of precipitation and a largely uninhabitable.

It would also be of benefit to possibly begin introducing this topic by asking students what they already knew about deserts, their locations, features etc as these ideas could either be confirmed or challenged through the later teaching, opening up further avenues of thought for the students to develop a greater understanding.

A brief introduction to deserts would lead nicely onto the processes that occur within deserts and the features that are formed as a result.