Iowa State University Iowa Atmospheric Observatory 120-m Tall tower measurements (5-min statistics)

The data contains monthly netCDF formatted files from the ISU tall tower instrumentation at the Iowa Atmospheric Observatory.

At five minute intervals, the 1 hertz data is statistically summarized to determine the mean, median, minimum, maximum, standard deviation, median absolute deviation, and the number of samples for each five-minute averaging period. Data is collected for each of the following meteorological variables (wind speed, wind direction, air temperature, relative humidity, and air pressure) using instruments (cup anemometer, wind vane, air temperature/relative humidity probe, and barometer, respectively) mounted on two tall towers at six heights above the ground surface (5 m, 10 m, 20 m, 40 m, 80 m, and 120 m). Duplicate measurements of wind speed, and wind direction refer to cup anemometer and wind vane instrumentation on the WNW and S oriented tower booms. One tower is located in Rural Story Co. Iowa within a 200-turbine wind farm and the other tower is located in Rural Hamilton Co. Iowa outside of the wind farm.

The data are supporting the analysis and results contained within the article: “Observations show that wind farms substantially modify the atmospheric boundary layer thermal stratification transition in the early evening” submitted to Geophysical Research Letters (Rajewski et al. 2020) to determine day-to-night changes in atmospheric stability, buoyancy, and wind shear, in the wakes of single turbines and in the wake of a utility-scale wind farm. Monthly data used in this article were taken from a portion of the June 2016- May 2018 data record to produce Figures 1-4 in the manuscript.

Data were also used from June 2016-September 2016 in the analysis presented in the IAO introductory publication (Takle et al. 2019).