Observing System Simulation Experiment Studies Using Small UAVs in the Boundary Layer in a 3D Mesonet Configuration

Several recent studies and workshops have concluded that many fields of atmospheric science and weather prediction would benefit from more frequent and dense observations of temperature, humidity and wind in the atmospheric boundary layer. One way to meet this need would be through a 3D Mesonet which would augment an automated surface weather network with autonomous vertical flights of small Unmanned Aerial Vehicles (sUAVs). This work reports on Observing System Simulation Experiment studies (OSSEs) testing various configurations of the 3D Mesonet including tests of maximum flight altitude, number of profiling sites and the time interval between flights. The OSSEs use a 1-km grid ARPS model simulation of the 20 May 2013 severe weather case as the nature run with a 3-km grid WRF-ARW as the test forecast model. Vertical profiles are generated from the nature run assuming profiling with a small copter-sonde having measurement error characteristics similar to high-quality radiosondes. We focus on the impact of the observations on the forecasts of convection initiation in the early afternoon using simulated data from the morning. It is found that the sUAV data has a positive impact on the convection initiation forecasts. An hourly profiling interval a 1-km AGL max sampling height is sufficient for this case and there is a benefit to an increasing number of sites, though that result is somewhat sensitive to the selection of sites and analysis parameter settings. Results of time interval testing are in progress and will be presented at the meeting.