Surface boundary layer turbulence measurements: Purdue Agronomy Center for Research and Education

<p>Dataset includes measurements of atmospheric turbulence made with 3-diemnsional sonic anemometers over 9 years (2013-2021) over level agricultural cropped land at 40.495 N -86.99 W. Measurements were made in support of micrometeorological gas exchange research projects.</p>

<ul>
<li>The RM Young 91000 3 dimensional sonic anemometers sampled the wind at 16Hz.</li>
<li>"Low" sonic measurements were made at 2.5 m above ground level.</li>
<li>"High" sonic measurements were made at 5.3 m above ground level.</li>
</ul>

<p>Turbulence measurement records consist of turbulence statistics (variances and covariances of 3 orthogonal wind components and sonic temperature) at 100s intervals.</p>

<ul>
<li>Turbulence statistics are provided for (1) valid data, (2) invalid data due to spike values (greater than 3 standard deviations of the 100s mean), and (3) invalid data due to more than 10% of the measurements in the 100s period missing due to optical path obstruction. </li>
</ul>

<p>Temporal gaps in measurements exist over the 9-year period due to instrument and communications failures as well as gaps due to no experimental need for the measurements.  Note that missing measurement periods do not have Date/Time record placeholders in the dataset.</p>

<p>Additional files included:</p>

<p>The sonic anemometer Standard Operating Procedure for the measurements is included: "SOP Ultrasonic Anemometer (Revision 1.0) 2-20-08.pdf'"</p>

<p>The Data Dictionary is 'Data Dictionary.pdf'</p>