@article{Morrisona2018,

title = {A novel method to obtain three-dimensional urban surface temperature from ground-based thermography},

author = {William Morrison and Simone Kotthaus and CSB Grimmond and Atsushi Inagaki and Tiangang Yin and Jean-Philippe Gastellu-Etchegorry and Manabu Kanda and Christopher J. Merchant},

url = {https://urbanfluxes.eu/wp-content/uploads/2018/07/2018_Morrison_et_al.pdf},

doi = {10.1016/j.rse.2018.05.004},

year  = {2018},

date = {2018-09-15},

journal = {Remote Sensing of Environment},

volume = {Volume 215},

pages = {268-283},

abstract = {Urban geometry and materials combine to create complex spatial, temporal and directional patterns of longwave infrared (LWIR) radiation. Effective anisotropy (or directional variability) of thermal radiance causes remote sensing (RS) derived urban surface temperatures to vary with RS view angles. Here a new and novel method to resolve effective thermal anisotropy processes from LWIR camera observations is demonstrated at the Comprehensive Outdoor Scale MOdel (COSMO) test site. Pixel-level differences of brightness temperatures reach 18.4 K within one hour of a 24-h study period. To understand this variability, the orientation and shadowing of surfaces is explored using the Discrete Anisotropic Radiative Transfer (DART) model and Blender three-dimensional (3D) rendering software. Observed pixels and the entire canopy surface are classified in terms of surface orientation and illumination. To assess the variability of exitant longwave radiation (MLW) from the 3D COSMO surface (), the observations are prescribed based on class. The parameterisation is tested by simulating thermal images using a camera view model to determine camera perspectives of fluxes. The mean brightness temperature differences per image (simulated and observed) are within 0.65 K throughout a 24-h period. Pixel-level comparisons are possible with the high spatial resolution of and DART camera view simulations. At this spatial scale (<0.10 m), shadow hysteresis, surface sky view factor and building edge effects are not completely resolved by . By simulating apparent brightness temperatures from multiple view directions, effective thermal anisotropy of is shown to be up to 6.18 K. The developed methods can be extended to resolve some of the identified sources of sub-facet variability in realistic urban settings. The extension of DART to the interpretation of ground-based RS is shown to be promising.},

keywords = {COSMO, DART, Ground-based thermography, Image classification, Sensor view modelling, Thermographic camera modelling, Upwelling longwave radiation, Urban meteorology},

pubstate = {published},

tppubtype = {article}

}

@article{Chrysoulakis2018,

title = {Urban energy exchanges monitoring from space},

author = {Nektarios Chrysoulakis and Sue Grimmond and Christian Feigenwinter and Fredrik Lindberg and Jean-Philippe Gastellu-Etchegorry and Mattia Marconcini and Zina Mitraka and Stavros Stagakis and Ben Crawford and Frans Olofson and Lucas Landier and William Morrison and Eberhard Parlow },

editor = {nature.com},

url = {https://urbanfluxes.eu/wp-content/uploads/2018/07/UF_Overview_final.pdf},

doi = {10.1038/s41598-018-29873-x},

issn = {2045-2322},

year  = {2018},

date = {2018-07-31},

journal = { nature.com },

volume = {Scientific Reports volume},

number = {8},

pages = {11498},

abstract = {One important challenge facing the urbanization and global environmental change community is to understand the relation between urban form, energy use and carbon emissions. Missing from the current literature are scientific assessments that evaluate the impacts of different urban spatial units on energy fluxes; yet, this type of analysis is needed by urban planners, who recognize that local scale zoning affects energy consumption and local climate. Satellite-based estimation of urban energy fluxes at neighbourhood scale is still a challenge. Here we show the potential of the current satellite missions to retrieve urban energy budget fluxes, supported by meteorological observations and evaluated by direct flux measurements. We found an agreement within 5% between satellite and in-situ derived net all-wave radiation; and identified that wall facet fraction and urban materials type are the most important parameters for estimating heat storage of the urban canopy. The satellite approaches were found to underestimate measured turbulent heat fluxes, with sensible heat flux being most sensitive to surface temperature variation (−64.1, +69.3 W m−2 for ±2 K perturbation).  They also underestimate anthropogenic heat fluxes. However, reasonable spatial patterns are obtained for the latter allowing hot-spots to be identified, therefore supporting both urban planning and urban climate modelling.},

keywords = {anthropogenic heat emission, Anthropogenic Heat Flux, Concentration profiles, Copernicus Sentinels, Earth Observation, Eddy-covariance, Flux measurements, Ground-based thermography, Image classification, reducing, Sensor view modelling, Street canyon, Thermographic camera modelling, Understanding, Upwelling longwave radiation, urban, Urban Climate, Urban Energy Budget, urban heat fluxes, Urban meteorology},

pubstate = {published},

tppubtype = {article}

}

@article{Morrisona2018,

title = {A novel method to obtain three-dimensional urban surface temperature from ground-based thermography},

author = {William Morrison and Simone Kotthaus and CSB Grimmond and Atsushi Inagaki and Tiangang Yin and Jean-Philippe Gastellu-Etchegorry and Manabu Kanda and Christopher J. Merchant},

url = {https://urbanfluxes.eu/wp-content/uploads/2018/07/2018_Morrison_et_al.pdf},

doi = {10.1016/j.rse.2018.05.004},

year  = {2018},

date = {2018-09-15},

journal = {Remote Sensing of Environment},

volume = {Volume 215},

pages = {268-283},

abstract = {Urban geometry and materials combine to create complex spatial, temporal and directional patterns of longwave infrared (LWIR) radiation. Effective anisotropy (or directional variability) of thermal radiance causes remote sensing (RS) derived urban surface temperatures to vary with RS view angles. Here a new and novel method to resolve effective thermal anisotropy processes from LWIR camera observations is demonstrated at the Comprehensive Outdoor Scale MOdel (COSMO) test site. Pixel-level differences of brightness temperatures reach 18.4 K within one hour of a 24-h study period. To understand this variability, the orientation and shadowing of surfaces is explored using the Discrete Anisotropic Radiative Transfer (DART) model and Blender three-dimensional (3D) rendering software. Observed pixels and the entire canopy surface are classified in terms of surface orientation and illumination. To assess the variability of exitant longwave radiation (MLW) from the 3D COSMO surface (), the observations are prescribed based on class. The parameterisation is tested by simulating thermal images using a camera view model to determine camera perspectives of fluxes. The mean brightness temperature differences per image (simulated and observed) are within 0.65 K throughout a 24-h period. Pixel-level comparisons are possible with the high spatial resolution of and DART camera view simulations. At this spatial scale (<0.10 m), shadow hysteresis, surface sky view factor and building edge effects are not completely resolved by . By simulating apparent brightness temperatures from multiple view directions, effective thermal anisotropy of is shown to be up to 6.18 K. The developed methods can be extended to resolve some of the identified sources of sub-facet variability in realistic urban settings. The extension of DART to the interpretation of ground-based RS is shown to be promising.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Chrysoulakis2018,

title = {Urban energy exchanges monitoring from space},

author = {Nektarios Chrysoulakis and Sue Grimmond and Christian Feigenwinter and Fredrik Lindberg and Jean-Philippe Gastellu-Etchegorry and Mattia Marconcini and Zina Mitraka and Stavros Stagakis and Ben Crawford and Frans Olofson and Lucas Landier and William Morrison and Eberhard Parlow },

editor = {nature.com},

url = {https://urbanfluxes.eu/wp-content/uploads/2018/07/UF_Overview_final.pdf},

doi = {10.1038/s41598-018-29873-x},

issn = {2045-2322},

year  = {2018},

date = {2018-07-31},

journal = { nature.com },

volume = {Scientific Reports volume},

number = {8},

pages = {11498},

abstract = {One important challenge facing the urbanization and global environmental change community is to understand the relation between urban form, energy use and carbon emissions. Missing from the current literature are scientific assessments that evaluate the impacts of different urban spatial units on energy fluxes; yet, this type of analysis is needed by urban planners, who recognize that local scale zoning affects energy consumption and local climate. Satellite-based estimation of urban energy fluxes at neighbourhood scale is still a challenge. Here we show the potential of the current satellite missions to retrieve urban energy budget fluxes, supported by meteorological observations and evaluated by direct flux measurements. We found an agreement within 5% between satellite and in-situ derived net all-wave radiation; and identified that wall facet fraction and urban materials type are the most important parameters for estimating heat storage of the urban canopy. The satellite approaches were found to underestimate measured turbulent heat fluxes, with sensible heat flux being most sensitive to surface temperature variation (−64.1, +69.3 W m−2 for ±2 K perturbation).  They also underestimate anthropogenic heat fluxes. However, reasonable spatial patterns are obtained for the latter allowing hot-spots to be identified, therefore supporting both urban planning and urban climate modelling.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}