The Growing Need for Measurements and Monitoring of Critical Properties and Processes at the Soil Surface.

The top inch of the earth’s soil surface is a very dynamic and important layer where physical and biogeochemical processes take place under extreme diurnal and seasonal variations in moisture and temperature. Some of these critical surfaces include biocrusts, desert pavements, agricultural lands, mine tailings and hydrophobic forest soils; all of which can significantly impact environmental conditions at large-scales. Natural hazards associated with surface conditions include dust storms posing health hazards, post-fire erosion and flooding in addition to crop failure. Less obvious, though continually occurring microbially-induced gas emissions are also significantly impacted by surface conditions. With so much at stake, it is surprising in today’s technological world that there are few if any sensors designed for monitoring the top inch of the soil surface. In particular, our future expectation for remote sensing imagery to provide near-real-time conditions of the earth’s surface necessitates ground calibration of the top inch, something that is presently lacking. Examples of the dynamics of surface conditions will be presented along with their impact on processes of interest and the need for near-surface measurements. Novel measurement solutions and their prospects to improve scientific methods will also be presented.