Campus Units

Agronomy

Document Type

Article

Publication Version

Accepted Manuscript

Publication Date

1-25-2019

Journal or Book Title

Earth Interactions

DOI

10.1175/EI-D-17-0024.1

Abstract

The Iowa Atmospheric Observatory was established to better understand the unique microclimate characteristics of a wind farm. The facility consists of a pair of 120 m towers identically instrumented to observe basic landscape-atmosphere interactions in a highly managed agricultural landscape. The towers, one within and one outside of a utility-scale low-density array wind farm, are equipped to measure vertical profiles of temperature, wind, moisture, and pressure and can host specialized sensors for a wide range of environmental conditions. Tower measurements during the 2016 growing season demonstrate the ability to distinguish microclimate differences created by single or multiple turbines from natural conditions over homogeneous agricultural fields. Microclimate differences between the two towers are reported as contrasts in normalized wind speed, normalized turbulence intensity, potential temperature, and water-vapor mixing ratio. Differences are analyzed according to conditions of no wind farm influence (i.e. no-wake) vs. wind farm influence (i.e. waked flow) with distance downwind from a single wind turbine or a large group of turbines. Differences are also determined for more specific atmospheric conditions according to thermal stratification. Results demonstrate agreement with most, but not all, currently available numerical flow field simulations of large wind farm arrays and of individual turbines. In particular, the well documented higher night-time surface temperature in wind farms is examined in vertical profiles that confirm this effect to be a “suppression of cooling” rather than a warming process. A summary is provided of how the wind-farm boundary layer differs from the natural boundary layer derived from concurrent measurements over the summer of 2016.

Comments

This is a manuscript of an article published as Takle, Eugene S., Daniel A. Rajewski, and Samantha L. Purdy. "The Iowa Atmospheric Observatory: Revealing the Unique Boundary-Layer Characteristics of a Wind Farm." Earth Interactions (2019). doi: 10.1175/EI-D-17-0024.1. Posted with permission.

Rights

© Copyright 2019 American Meteorological Society (AMS). Permission to use figures, tables, and brief excerpts from this work in scientific and educational works is hereby granted provided that the source is acknowledged. Any use of material in this work that is determined to be “fair use” under Section 107 of the U.S. Copyright Act or that satisfies the conditions specified in Section 108 of the U.S. Copyright Act (17 USC §108) does not require the AMS’s permission. Republication, systematic reproduction, posting in electronic form, such as on a website or in a searchable database, or other uses of this material, except as exempted by the above statement, requires written permission or a license from the AMS. All AMS journals and monograph publications are registered with the Copyright Clearance Center (http://www.copyright.com). Questions about permission to use materials for which AMS holds the copyright can also be directed to permissions@ametsoc.org. Additional details are provided in the AMS Copyright Policy statement, available on the AMS website (http://www.ametsoc.org/CopyrightInformation).

Copyright Owner

American Meteorological Society

Language

en

File Format

application/pdf

Available for download on Thursday, July 25, 2019

Published Version

Share

COinS