Realtime WRF LES Simulations to Support UAS Flight Planning and Operations During 2018 LAPSE-RATE

Abstract

Abstract. The simulations were forced using data from the High-Resolution Rapid Refresh (HRRR) and the Global Forecast System (GFS) obtained from the National Center for Environmental Prediction (NCEP) Central Operations (NCO). The nested WRF configuration used in this study featured a large-eddy-permitting, 111-m grid spacing mesh for the inner-most domain. Output from the WRF forecasts were processed on-the-fly using the Unified Post Processor (UPP). A THREDDS data server was coupled with a web-viewer to provide real-time graphics that were used to support UAS flight planning and decision making. The simulations ran in under six hours on the National Center for Atmospheric Research (NCAR) Cheyenne supercomputer using 59 cores (2124 processors). The simulations were run twice per day (12 runs total during the experiment) to support both next-day mission planning and day-of tactical guidance. The simulations provided a high-resolution depiction of the four-dimensional variability of weather conditions across the northern half of the San Luis Valley, Colorado, where UAS operations took place. The simulations were used to assess the possibility of a number of small UAS weather hazards including wind shift boundaries, vertical shear, strong thermals, turbulence intensity, fog, low ceilings, and thunderstorms. Details of the model configuration used to perform the simulations and the data processing steps used to produce the final grids of state variables and other sensible weather products (e.g., ceiling and visibility, turbulence) are given. A few examples of predictive capabilities of the modeling system are provided to illustrate the skill of the model at predicting fine-scale boundary layer structures and turbulence associated with drainage winds, up-valley flows, and convective storm outflows. A subset of the at data is available at the Zenodo data archive (https://zenodo.org/communities/lapse-rate/) while full dataset (see Pinto et al. 2020a) is archived on the NCAR Digital Asset Services Hub (DASH) and may be obtained at https://doi.org/10.5065/83r2-0579.

Data generated during the 2018 LAPSE-RATE campaign: an introduction and overview

“…This was largely decided the day before during an all-teams briefing in which weather forecasts and platform readiness were discussed. Forecast guidance for planning came through joint input from the National Weather Service and highresolution simulations from the Weather Research and Forecasting (WRF) model (Pinto et al, 2020;Nolan et al, 2018). These include surface pressure (c), air temperature (d), relative humidity (e), and wind speed (f).…”

“…Finally, given that only a limited number of teams were interested in studying aerosol processes during the campaign, these measurements were made continuously at a single site approximately 15 km north of Leach Airport, using UAS- National Center for Atmospheric Research Campaign forecasting, production of numerical forecast products, modeling and postcampaign support Pinto et al (2020) Finnish Meteorological Institute Operation of unmanned aircraft Brus et al 2020Black Swift Technologies Operation of unmanned aircraft de Boer et al (2020b) based sensors as well as from the surface (see Brus et al, 2020, in this special issue).…”

“…Knuth et al, 2013), during a total solar eclipse (Bailey, et al, 2019), and in and around supercell thunderstorms (e.g., Elston et al, 2011). Beyond the PBL, data gathered by UASs have shed light on interactions between the atmosphere and other components of the Earth system (e.g., oceans, ice, land surface), with campaigns covering both lower latitudes (e.g., Corrigan et al, 2006;Ramanathan et al, 2007;van den Kroonenberg et al, 2008;Houston et al, 2012) and higher latitudes (e.g., Curry et al, 2004;Cassano et al, 2010;Knuth and Cassano, 2014;Kral et al, 2018).…”

Measurements from mobile surface vehicles during the Lower Atmospheric Profiling Studies at Elevation – a Remotely-piloted Aircraft Team Experiment (LAPSE-RATE)

“…Information on the different UASs and profilers deployed during LAPSE-RATE, numerical simulations completed for the campaign, and an overview of the campaign itself is distributed in a range of articles, many of which are associated with this Earth System Science Data special issue and will not be revisited here (de Boer et al, 2020b, c;Bell et al, 2020;Pillar-Little et al, 2020;Bailey et al, 2020;Natalie et al, 2021;Islam et al, 2020;Brus et al, 2020;Pinto et al, 2020). The current paper is focused on describing datasets collected using mobile surface observing systems during the LAPSE-RATE campaign.…”