The findings show for the first time how water vapor penetrates powders and grains, and could have wide-ranging applications far beyond the desert -- in pharmaceutical research, agriculture and food processing, as well as planetary exploration.
The team's paper published in the Journal of Geophysical Research-Earth Surface.
Wanting to measure matter with greater sensitivity, lead author Michel Louge, professor of mechanical and aerospace engineering at Cornell University, developed a new form of instrumentation called capacitance probes, which use multiple sensors to record everything from solid concentration to velocity to water content, all with unprecedented spatial resolution.
In the early 2000s, Louge began collaborating with Ahmed Ould el-Moctar from University of Nantes, France, to use the probes to study the moisture content in sand dunes to better understand the process by which agricultural lands turn to desert -- an interest that has only become more urgent with the rise of global climate change.
The probe eventually revealed just how porous sand is, with a tiny amount of air seeping through it. Previous research hinted this type of seepage existed in sand dunes, but no one had been able to prove it until now.