Figure 4

Summer temperatures measured at different locations during a characteristic time span, January 3–7, 2006. (A) Temperatures measured at a height of 1.80 m (ambient air temperature), at the quartz pebble surface, inside a quartz pebble, under a thick quartz pebble, and at a depth of 30 mm underneath a quartz field. (B) Temperatures measured at the surface of epigaeic soil crusts and under a thin and a thick quartz pebble. For dimensions of quartz pebbles, see Table 1.