Strong influence of convective heat transfer efficiency on the cooling benefits of green roof irrigation
Abstract
Abstract By enhancing evapotranspiration (ET), green roofs provide cooling benefits for the urban environment and are recognized as a promising heat mitigation strategy. The evaporative cooling effects of green roofs strongly depend on the soil moisture conditions and thus irrigation may be needed to sustain the cooling benefits. It has been shown that the magnitude of cooling benefits offered by green roof irrigation varies spatially, but its controlling factors remain elusive. In this study, we combine a surface energy balance (SEB) model with global simulations generated by an improved Earth System Model to illustrate the key factors controlling the cooling benefits of green roof irrigation. We employ a simple irrigation scheme, which is only active when there is no ice in soil layers and when the soil moisture is below field capacity. As a result, most of the irrigation water leaves the green roof system via ET. We find that the magnitude and also the spatial variability of the cooling benefits of green roof irrigation are controlled by the irrigation amount, and a surface energy redistribution factor that encodes the efficiencies of different SEB components in transferring heat. Further analysis indicates that the enhancement of latent heat flux due tomore »
- Publication Date:
- Sponsoring Org.:
- USDOE
- OSTI Identifier:
- 1835467
- Resource Type:
- Published Article
- Journal Name:
- Environmental Research Letters
- Additional Journal Information:
- Journal Name: Environmental Research Letters Journal Volume: 16 Journal Issue: 8; Journal ID: ISSN 1748-9326
- Publisher:
- IOP Publishing
- Country of Publication:
- United Kingdom
- Language:
- English
Citation Formats
Wang, Linying, Huang, Maoyi, and Li, Dan. Strong influence of convective heat transfer efficiency on the cooling benefits of green roof irrigation. United Kingdom: N. p., 2021.
Web. doi:10.1088/1748-9326/ac18ea.
Wang, Linying, Huang, Maoyi, & Li, Dan. Strong influence of convective heat transfer efficiency on the cooling benefits of green roof irrigation. United Kingdom. https://doi.org/10.1088/1748-9326/ac18ea
Wang, Linying, Huang, Maoyi, and Li, Dan. Tue .
"Strong influence of convective heat transfer efficiency on the cooling benefits of green roof irrigation". United Kingdom. https://doi.org/10.1088/1748-9326/ac18ea.
@article{osti_1835467,
title = {Strong influence of convective heat transfer efficiency on the cooling benefits of green roof irrigation},
author = {Wang, Linying and Huang, Maoyi and Li, Dan},
abstractNote = {Abstract By enhancing evapotranspiration (ET), green roofs provide cooling benefits for the urban environment and are recognized as a promising heat mitigation strategy. The evaporative cooling effects of green roofs strongly depend on the soil moisture conditions and thus irrigation may be needed to sustain the cooling benefits. It has been shown that the magnitude of cooling benefits offered by green roof irrigation varies spatially, but its controlling factors remain elusive. In this study, we combine a surface energy balance (SEB) model with global simulations generated by an improved Earth System Model to illustrate the key factors controlling the cooling benefits of green roof irrigation. We employ a simple irrigation scheme, which is only active when there is no ice in soil layers and when the soil moisture is below field capacity. As a result, most of the irrigation water leaves the green roof system via ET. We find that the magnitude and also the spatial variability of the cooling benefits of green roof irrigation are controlled by the irrigation amount, and a surface energy redistribution factor that encodes the efficiencies of different SEB components in transferring heat. Further analysis indicates that the enhancement of latent heat flux due to irrigation is largely balanced by the reduction of sensible heat flux on green roofs. Therefore, the amount of irrigation needed per unit decrease of green roof surface temperature is mainly controlled by the convective heat transfer efficiency. A lower convective heat transfer efficiency (e.g. under a lower wind speed) helps reduce the amount of irrigation needed per unit decrease of green roof surface temperature. This study highlights the importance of SEB in constraining the cooling benefits of green roof irrigation and provides valuable guidance for urban planners and policy makers in terms of heat mitigation and sustainable water management.},
doi = {10.1088/1748-9326/ac18ea},
journal = {Environmental Research Letters},
number = 8,
volume = 16,
place = {United Kingdom},
year = {Tue Aug 10 00:00:00 EDT 2021},
month = {Tue Aug 10 00:00:00 EDT 2021}
}
Free Publicly Available Full Text
Publisher's Version of Record
https://doi.org/10.1088/1748-9326/ac18ea
https://doi.org/10.1088/1748-9326/ac18ea
Other availability
Search WorldCat to find libraries that may hold this journal
Save to My Library
You must Sign In or Create an Account in order to save documents to your library.
Works referenced in this record:
Investigation of thermal benefits of rooftop garden in the tropical environment
journal, February 2003
- Wong, Nyuk Hien; Chen, Yu; Ong, Chui Leng
- Building and Environment, Vol. 38, Issue 2
Relative efficiency of land surface energy balance components: EFFICIENCY OF ENERGY BALANCE COMPONENTS
journal, April 2012
- Bateni, S. M.; Entekhabi, D.
- Water Resources Research, Vol. 48, Issue 4
A study on the cooling effects of greening in a high-density city: An experience from Hong Kong
journal, January 2012
- Ng, Edward; Chen, Liang; Wang, Yingna
- Building and Environment, Vol. 47
Intercomparisons of Experimental Convective Heat Transfer Coefficients and Mass Transfer Coefficients of Urban Surfaces
journal, December 2005
- Hagishima, Aya; Tanimoto, Jun; Narita, Ken-ich
- Boundary-Layer Meteorology, Vol. 117, Issue 3
Urban water capacity: Irrigation for heat mitigation
journal, November 2019
- Wang, Chenghao; Wang, Zhi-Hua; Yang, Jiachuan
- Computers, Environment and Urban Systems, Vol. 78
To irrigate or not to irrigate: Analysis of green roof performance via a vertically-resolved hygrothermal model
journal, March 2014
- Sun, Ting; Bou-Zeid, Elie; Ni, Guang-Heng
- Building and Environment, Vol. 73
Applying artificial intelligence modeling to optimize green roof irrigation
journal, September 2016
- Tsang, S. W.; Jim, C. Y.
- Energy and Buildings, Vol. 127
Planning for a sustainable desert city: The potential water buffering capacity of urban green infrastructure
journal, November 2017
- Yang, Jiachuan; Wang, Zhi-Hua
- Landscape and Urban Planning, Vol. 167
Development of a Green Roof Environmental Monitoring and Meteorological Network in New York City
journal, April 2009
- Gaffin, Stuart; Khanbilvardi, Reza; Rosenzweig, Cynthia
- Sensors, Vol. 9, Issue 4
Green and cool roofs’ urban heat island mitigation potential in European climates for office buildings under free floating conditions
journal, September 2013
- Kolokotsa, D.; Santamouris, M.; Zerefos, S. C.
- Solar Energy, Vol. 95
The effectiveness of cool and green roofs as urban heat island mitigation strategies
journal, May 2014
- Li, Dan; Bou-Zeid, Elie; Oppenheimer, Michael
- Environmental Research Letters, Vol. 9, Issue 5
Disentangling the response of forest and grassland energy exchange to heatwaves under idealized land–atmosphere coupling
journal, January 2014
- van Heerwaarden, C. C.; Teuling, A. J.
- Biogeosciences, Vol. 11, Issue 21
A coupled energy transport and hydrological model for urban canopies evaluated using a wireless sensor network
journal, October 2012
- Wang, Zhi-Hua; Bou-Zeid, Elie; Smith, James A.
- Quarterly Journal of the Royal Meteorological Society, Vol. 139, Issue 675
Study on heat fluxes of green roofs based on an improved heat and mass transfer model
journal, October 2017
- Tian, Yudi; Bai, Xuelian; Qi, Ben
- Energy and Buildings, Vol. 152
Modeling the reduction of urban excess heat by green roofs with respect to different irrigation scenarios
journal, March 2018
- Heusinger, Jannik; Sailor, David J.; Weber, Stephan
- Building and Environment, Vol. 131
A HYDRUS model for irrigation management of green roofs with a water storage layer
journal, October 2016
- Qin, Hua-peng; Peng, Yue-nuan; Tang, Qiao-ling
- Ecological Engineering, Vol. 95
A green roof model for building energy simulation programs
journal, January 2008
- Sailor, D. J.
- Energy and Buildings, Vol. 40, Issue 8
Air-quality implications of widespread adoption of cool roofs on ozone and particulate matter in southern California
journal, August 2017
- Epstein, Scott A.; Lee, Sang-Mi; Katzenstein, Aaron S.
- Proceedings of the National Academy of Sciences, Vol. 114, Issue 34
A global economic assessment of city policies to reduce climate change impacts
journal, May 2017
- Estrada, Francisco; Botzen, W. J. Wouter; Tol, Richard S. J.
- Nature Climate Change, Vol. 7, Issue 6
Optimizing urban irrigation schemes for the trade-off between energy and water consumption
journal, November 2015
- Yang, Jiachuan; Wang, Zhi-Hua
- Energy and Buildings, Vol. 107
The Regional Impact of Urban Heat Mitigation Strategies on Planetary Boundary Layer Dynamics Over a Semiarid City
journal, June 2018
- Song, Jiyun; Wang, Zhi‐Hua; Wang, Chenghao
- Journal of Geophysical Research: Atmospheres, Vol. 123, Issue 12
Urban adaptation can roll back warming of emerging megapolitan regions
journal, February 2014
- Georgescu, M.; Morefield, P. E.; Bierwagen, B. G.
- Proceedings of the National Academy of Sciences, Vol. 111, Issue 8
Utilising green and bluespace to mitigate urban heat island intensity
journal, April 2017
- Gunawardena, K. R.; Wells, M. J.; Kershaw, T.
- Science of The Total Environment, Vol. 584-585
Sensitivity of Surface Temperature to Land Use and Land Cover Change‐Induced Biophysical Changes: The Scale Issue
journal, August 2019
- Li, Dan; Wang, Liang
- Geophysical Research Letters, Vol. 46, Issue 16
Long-term thermal performance evaluation of green roof system based on two new indexes: A case study in Shanghai area
journal, August 2017
- He, Yang; Yu, Hang; Ozaki, Akihito
- Building and Environment, Vol. 120
Water conservation benefits of urban heat mitigation
journal, October 2017
- Vahmani, Pouya; Jones, Andrew D.
- Nature Communications, Vol. 8, Issue 1
An examination of urban heat island characteristics in a global climate model
journal, July 2010
- Oleson, K. W.; Bonan, G. B.; Feddema, J.
- International Journal of Climatology, Vol. 31, Issue 12
Where Are White Roofs More Effective in Cooling the Surface?
journal, August 2020
- Wang, Linying; Huang, Maoyi; Li, Dan
- Geophysical Research Letters, Vol. 47, Issue 15
Adapting green roof irrigation practices for a sustainable future: A review
journal, December 2015
- Van Mechelen, Carmen; Dutoit, Thierry; Hermy, Martin
- Sustainable Cities and Society, Vol. 19
Green roofs and facades: A comprehensive review
journal, February 2018
- Besir, Ahmet B.; Cuce, Erdem
- Renewable and Sustainable Energy Reviews, Vol. 82
Incorporating an Urban Irrigation Module into the Noah Land Surface Model Coupled with an Urban Canopy Model
journal, August 2014
- Vahmani, Pouya; Hogue, Terri S.
- Journal of Hydrometeorology, Vol. 15, Issue 4
Parameterization of Urban Characteristics for Global Climate Modeling
journal, August 2010
- Jackson, Trisha L.; Feddema, Johannes J.; Oleson, Keith W.
- Annals of the Association of American Geographers, Vol. 100, Issue 4
How do green roofs mitigate urban thermal stress under heat waves?: Green Roofs Reduce Urban Thermal Stress
journal, May 2016
- Sun, Ting; Grimmond, C. S. B.; Ni, Guang-Heng
- Journal of Geophysical Research: Atmospheres, Vol. 121, Issue 10
Cooling hot cities: a systematic and critical review of the numerical modelling literature
journal, May 2021
- Krayenhoff, E. Scott; Broadbent, Ashley M.; Zhao, Lei
- Environmental Research Letters, Vol. 16, Issue 5
Quality and reliability of LES of convective scalar transfer at high Reynolds numbers
journal, November 2016
- Li, Qi; Bou-Zeid, Elie; Anderson, William
- International Journal of Heat and Mass Transfer, Vol. 102
Hydrometeorological determinants of green roof performance via a vertically-resolved model for heat and water transport
journal, February 2013
- Sun, Ting; Bou-Zeid, Elie; Wang, Zhi-Hua
- Building and Environment, Vol. 60
Green and cool roofs to mitigate urban heat island effects in the Chicago metropolitan area: evaluation with a regional climate model
journal, June 2016
- Sharma, A.; Conry, P.; Fernando, H. J. S.
- Environmental Research Letters, Vol. 11, Issue 6
Effect of irrigation on the experimental thermal performance of a green roof in a semi-warm climate in Mexico
journal, November 2017
- Chagolla-Aranda, M. A.; Simá, E.; Xamán, J.
- Energy and Buildings, Vol. 154
The Interpretation of the Variations in Leaf Water Potential and Stomatal Conductance Found in Canopies in the Field
journal, February 1976
- Jarvis, P. G.
- Philosophical Transactions of the Royal Society B: Biological Sciences, Vol. 273, Issue 927
Green Roof Mitigation Potential for a Proxy Future Climate Scenario in Chicago, Illinois
journal, March 2011
- Smith, Kathryn R.; Roebber, Paul J.
- Journal of Applied Meteorology and Climatology, Vol. 50, Issue 3
Challenges Associated with Adaptation to Future Urban Expansion
journal, March 2015
- Georgescu, M.
- Journal of Climate, Vol. 28, Issue 7
Cooling the cities – A review of reflective and green roof mitigation technologies to fight heat island and improve comfort in urban environments
journal, May 2014
- Santamouris, M.
- Solar Energy, Vol. 103
Green roof benefits, opportunities and challenges – A review
journal, July 2018
- Shafique, Muhammad; Kim, Reeho; Rafiq, Muhammad
- Renewable and Sustainable Energy Reviews, Vol. 90
Enhancing Hydrologic Modelling in the Coupled Weather Research and Forecasting–Urban Modelling System
journal, December 2014
- Yang, Jiachuan; Wang, Zhi-Hua; Chen, Fei
- Boundary-Layer Meteorology, Vol. 155, Issue 1
An environmental cost-benefit analysis of alternative green roofing strategies
journal, October 2016
- William, Reshmina; Goodwell, Allison; Richardson, Meredith
- Ecological Engineering, Vol. 95
The Community Earth System Model Version 2 (CESM2)
journal, February 2020
- Danabasoglu, G.; Lamarque, J. ‐F.; Bacmeister, J.
- Journal of Advances in Modeling Earth Systems, Vol. 12, Issue 2
The Community Land Model Version 5: Description of New Features, Benchmarking, and Impact of Forcing Uncertainty
journal, December 2019
- Lawrence, David M.; Fisher, Rosie A.; Koven, Charles D.
- Journal of Advances in Modeling Earth Systems, Vol. 11, Issue 12
Applicability of Classical Predictive Equations for the Estimation of Evapotranspiration from Urban Green Spaces: Green Roof Results
journal, January 2013
- DiGiovanni, Kimberly; Montalto, Franco; Gaffin, Stuart
- Journal of Hydrologic Engineering, Vol. 18, Issue 1
The adoption of green roofs for the retrofitting of existing buildings in the Mediterranean climate
journal, April 2016
- Gagliano, A.; Detommaso, M.; Nocera, F.
- International Journal of Sustainable Building Technology and Urban Development, Vol. 7, Issue 2
Cool and green roofs. An energy and comfort comparison between passive cooling and mitigation urban heat island techniques for residential buildings in the Mediterranean region
journal, December 2012
- Zinzi, M.; Agnoli, S.
- Energy and Buildings, Vol. 55
Theoretical evaluation of thermal and energy performance of tropical green roofs
journal, May 2011
- Tsang, S. W.; Jim, C. Y.
- Energy, Vol. 36, Issue 5
Urban irrigation effects on WRF‐UCM summertime forecast skill over the Los Angeles metropolitan area
journal, October 2015
- Vahmani, P.; Hogue, T. S.
- Journal of Geophysical Research: Atmospheres, Vol. 120, Issue 19
Parameterization and Surface Data Improvements and New Capabilities for the Community Land Model Urban (CLMU)
journal, February 2020
- Oleson, K. W.; Feddema, J.
- Journal of Advances in Modeling Earth Systems, Vol. 12, Issue 2
Photosynthesis and water use by two Sedum species in green roof substrate
journal, November 2014
- Starry, O.; Lea-Cox, J. D.; Kim, J.
- Environmental and Experimental Botany, Vol. 107