Lower atmospheric flux measurements are a difficult subset of atmospheric data to accurately collect. The interplay of cost, precision, specialty, resolution and repeatability compound an already difficult experimental problem. In response to this, a new, novel instrumentation approach to measuring within the atmospheric boundary layer (ABL) is introduced.
The combination of Unmanned Aerial Vehicles (UAVs) and Distributed Temperature Sensing (DTS) technology are an unlikely pairing that show great potential for providing unprecedented levels of spatial and temporal resolution of the natural world. This pairing was deployed to the Oxbow Conservation Area near Bates, OR in July 2015 to measure vertically stratified temperature profiles. Additional modifications to the fiber optic cables were done in order to replicate the sling psychrometer approach to measuring humidity values by replicating a ‘dry’ and ‘wet’ bulb thermometer capable of measuring temperature gradients at high spatial and temporal resolutions.
Out of 23 UAV flights conducted, thirteen provided usable data. Measurements and calculations were compared to a co-located Open Path Gas Analyzer and Sonic Anemometer (Irgason) for accuracy and precision. Four flights showed strong correlation to Eddy-Covariance calculations on sensible heat and evaporative flux. More so, the modified DTS field deployment provided new insights into stratified heterogeneities in vapor pressure, temperature, sensible heat, evaporative flux and temperature variance.