Observed Thermal Impacts of Wind Farms Over Northern Illinois

This paper assesses impacts of three wind farms in northern Illinois using land surface temperature (LST) data from the Moderate Resolution Imaging Spectroradiometer (MODIS) instruments onboard the Terra and Aqua satellites for the period 2003–2013. Changes in LST between two periods (before and aft...

Full description

Bibliographic Details
Main Authors: Lauren M. Slawsky, Liming Zhou, Somnath Baidya Roy, Geng Xia, Mathias Vuille, Ronald A. Harris
Format: Article
Language:English
Published: MDPI AG 2015-06-01
Series:Sensors
Subjects:
Online Access:http://www.mdpi.com/1424-8220/15/7/14981
_version_ 1798042520171577344
author Lauren M. Slawsky
Liming Zhou
Somnath Baidya Roy
Geng Xia
Mathias Vuille
Ronald A. Harris
author_facet Lauren M. Slawsky
Liming Zhou
Somnath Baidya Roy
Geng Xia
Mathias Vuille
Ronald A. Harris
author_sort Lauren M. Slawsky
collection DOAJ
description This paper assesses impacts of three wind farms in northern Illinois using land surface temperature (LST) data from the Moderate Resolution Imaging Spectroradiometer (MODIS) instruments onboard the Terra and Aqua satellites for the period 2003–2013. Changes in LST between two periods (before and after construction of the wind turbines) and between wind farm pixels and nearby non-wind-farm pixels are quantified. An areal mean increase in LST by 0.18–0.39 °C is observed at nighttime over the wind farms, with the geographic distribution of this warming effect generally spatially coupled with the layout of the wind turbines (referred to as the spatial coupling), while there is no apparent impact on daytime LST. The nighttime LST warming effect varies with seasons, with the strongest warming in winter months of December-February, and the tightest spatial coupling in summer months of June-August. Analysis of seasonal variations in wind speed and direction from weather balloon sounding data and Automated Surface Observing System hourly observations from nearby stations suggest stronger winds correspond to seasons with greater warming and larger downwind impacts. The early morning soundings in Illinois are representative of the nighttime boundary layer and exhibit strong temperature inversions across all seasons. The strong and relatively shallow inversion in summer leaves warm air readily available to be mixed down and spatially well coupled with the turbine. Although the warming effect is strongest in winter, the spatial coupling is more erratic and spread out than in summer. These results suggest that the observed warming signal at nighttime is likely due to the net downward transport of heat from warmer air aloft to the surface, caused by the turbulent mixing in the wakes of the spinning turbine rotor blades.
first_indexed 2024-04-11T22:36:36Z
format Article
id doaj.art-50a587a9bf5048bb97d1ff725007e8b4
institution Directory Open Access Journal
issn 1424-8220
language English
last_indexed 2024-04-11T22:36:36Z
publishDate 2015-06-01
publisher MDPI AG
record_format Article
series Sensors
spelling doaj.art-50a587a9bf5048bb97d1ff725007e8b42022-12-22T03:59:12ZengMDPI AGSensors1424-82202015-06-01157149811500510.3390/s150714981s150714981Observed Thermal Impacts of Wind Farms Over Northern IllinoisLauren M. Slawsky0Liming Zhou1Somnath Baidya Roy2Geng Xia3Mathias Vuille4Ronald A. Harris5Department of Atmospheric and Environmental Sciences, SUNY at Albany, Albany, NY 12222, USADepartment of Atmospheric and Environmental Sciences, SUNY at Albany, Albany, NY 12222, USACentre for Atmospheric Sciences, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, IndiaDepartment of Atmospheric and Environmental Sciences, SUNY at Albany, Albany, NY 12222, USADepartment of Atmospheric and Environmental Sciences, SUNY at Albany, Albany, NY 12222, USADepartment of Atmospheric and Environmental Sciences, SUNY at Albany, Albany, NY 12222, USAThis paper assesses impacts of three wind farms in northern Illinois using land surface temperature (LST) data from the Moderate Resolution Imaging Spectroradiometer (MODIS) instruments onboard the Terra and Aqua satellites for the period 2003–2013. Changes in LST between two periods (before and after construction of the wind turbines) and between wind farm pixels and nearby non-wind-farm pixels are quantified. An areal mean increase in LST by 0.18–0.39 °C is observed at nighttime over the wind farms, with the geographic distribution of this warming effect generally spatially coupled with the layout of the wind turbines (referred to as the spatial coupling), while there is no apparent impact on daytime LST. The nighttime LST warming effect varies with seasons, with the strongest warming in winter months of December-February, and the tightest spatial coupling in summer months of June-August. Analysis of seasonal variations in wind speed and direction from weather balloon sounding data and Automated Surface Observing System hourly observations from nearby stations suggest stronger winds correspond to seasons with greater warming and larger downwind impacts. The early morning soundings in Illinois are representative of the nighttime boundary layer and exhibit strong temperature inversions across all seasons. The strong and relatively shallow inversion in summer leaves warm air readily available to be mixed down and spatially well coupled with the turbine. Although the warming effect is strongest in winter, the spatial coupling is more erratic and spread out than in summer. These results suggest that the observed warming signal at nighttime is likely due to the net downward transport of heat from warmer air aloft to the surface, caused by the turbulent mixing in the wakes of the spinning turbine rotor blades.http://www.mdpi.com/1424-8220/15/7/14981wind farm impactatmospheric boundary layerland surface temperature
spellingShingle Lauren M. Slawsky
Liming Zhou
Somnath Baidya Roy
Geng Xia
Mathias Vuille
Ronald A. Harris
Observed Thermal Impacts of Wind Farms Over Northern Illinois
Sensors
wind farm impact
atmospheric boundary layer
land surface temperature
title Observed Thermal Impacts of Wind Farms Over Northern Illinois
title_full Observed Thermal Impacts of Wind Farms Over Northern Illinois
title_fullStr Observed Thermal Impacts of Wind Farms Over Northern Illinois
title_full_unstemmed Observed Thermal Impacts of Wind Farms Over Northern Illinois
title_short Observed Thermal Impacts of Wind Farms Over Northern Illinois
title_sort observed thermal impacts of wind farms over northern illinois
topic wind farm impact
atmospheric boundary layer
land surface temperature
url http://www.mdpi.com/1424-8220/15/7/14981
work_keys_str_mv AT laurenmslawsky observedthermalimpactsofwindfarmsovernorthernillinois
AT limingzhou observedthermalimpactsofwindfarmsovernorthernillinois
AT somnathbaidyaroy observedthermalimpactsofwindfarmsovernorthernillinois
AT gengxia observedthermalimpactsofwindfarmsovernorthernillinois
AT mathiasvuille observedthermalimpactsofwindfarmsovernorthernillinois
AT ronaldaharris observedthermalimpactsofwindfarmsovernorthernillinois