Abstract
Infrasound from a 60-turbine wind farm was found to propagate to distances up to 90 km under nighttime atmospheric conditions. Four infrasound sensor arrays were deployed in central New Mexico in February 2014; three of these arrays captured infrasound from a large wind farm. The arrays were in a linear configuration oriented southeast with 13, 54, 90, and 126 km radial distances and azimuths of 166°, 119°, 113°, and 111° from the 60 1.6 MW turbine Red Mesa Wind Farm, Laguna Pueblo, New Mexico, USA. Peaks at a fundamental frequency slightly below 0.9 Hz and its harmonics characterize the spectrum of the detected infrasound. The generation of this signal is linked to the interaction of the blades, flow gradients, and the supporting tower. The production of wind-farm sound, its propagation, and detection at long distances can be related to the characteristics of the atmospheric boundary layer. First, under stable conditions, mostly occurring at night, winds are highly stratified, which enhances the production of thickness sound and the modulation of other higher-frequency wind turbine sounds. Second, nocturnal atmospheric conditions can create low-altitude waveguides (with altitudes on the order of hundreds of meters) allowing long-distance propagation. Third, night and early morning hours are characterized by reduced background atmospheric noise that enhances signal detectability. This work describes the characteristics of the infrasound from a quasi-continuous source with the potential for long-range propagation that could be used to monitor the lower part of the atmospheric boundary layer.
| Original language | English |
|---|---|
| Pages (from-to) | 9855-9868 |
| Number of pages | 14 |
| Journal | Journal of Geophysical Research: Biogeosciences |
| Volume | 120 |
| Issue number | 19 |
| DOIs | |
| State | Published - 2015 |
| Externally published | Yes |
Funding
Data for arrays LAG, MOT, and LISA are being submitted to IRIS-DMC (http://ds. iris.edu/ds/nodes/dmc/) under the experiment name and number: “Microbaroms” 201363, respectively. The raw waveforms from the SNL array are proprietary of Sandia National Laboratories and not publicly available; however, the results of the f-k analysis for this array can be retrieved from https://github.com/omarmarcillo/SNL-array-f-k-results.git. The radiosonde data are available at the repository of the Department of Atmospheric Science of the University of Wyoming (http:// weather.uwyo.edu/upperair/sounding. html). We thank D. Baker and E. Morton for field deployments and R. Whitaker and Y.J. Kim for their comments on different aspects of this work, which helped to strengthen this paper. We thank also D. Beecher from the Environmental Department of Pueblo of Laguna for her support in the deployment of the LAG array. This research was funded by the Los Alamos Laboratory Directed Research and Development program. Sandia National Laboratories is a multiprogram laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000.
| Funders | Funder number |
|---|---|
| Los Alamos Laboratory Directed Research and Development program | |
| Sandia Corporation | |
| Lockheed Martin Corporation | |
| National Nuclear Security Administration | DE-AC04-94AL85000 |
| Sandia National Laboratories |
