{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,19]],"date-time":"2026-09-19T12:26:57Z","timestamp":1789820817854,"version":"4.0.1"},"reference-count":56,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2016,1,30]],"date-time":"2016-01-30T00:00:00Z","timestamp":1454112000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Surface temperature is a key variable in boundary-layer meteorology and is typically acquired by remote observation of emitted thermal radiation. However, the three-dimensional structure of cities complicates matters: uneven solar heating of urban facets produces an \u201ceffective anisotropy\u201d of surface thermal emission at the neighbourhood scale. Remotely-sensed urban surface temperature varies with sensor view angle as a consequence. The authors combine a microscale urban surface temperature model with a thermal remote sensing model to predict the effective anisotropy of simplified neighbourhood configurations. The former model provides detailed surface temperature distributions for a range of \u201curban\u201d forms, and the remote sensing model computes aggregate temperatures for multiple view angles. The combined model\u2019s ability to reproduce observed anisotropy is evaluated against measurements from a neighbourhood in Vancouver, Canada. As in previous modeling studies, anisotropy is underestimated. Addition of moderate coverages of small (sub-facet scale) structure can account for much of the missing anisotropy. Subsequently, over 1900 sensitivity simulations are performed with the model combination, and the dependence of daytime effective thermal anisotropy on diurnal solar path (i.e., latitude and time of day) and blunt neighbourhood form is assessed. The range of effective anisotropy, as well as the maximum difference from nadir-observed brightness temperature, peak for moderate building-height-to-spacing ratios (H\/W), and scale with canyon (between-building) area; dispersed high-rise urban forms generate maximum anisotropy. Maximum anisotropy increases with solar elevation and scales with shortwave irradiance. Moreover, it depends linearly on H\/W for H\/W &lt; 1.25, with a slope that depends on maximum off-nadir sensor angle. Decreasing minimum brightness temperature is primarily responsible for this linear growth of maximum anisotropy. These results allow first order estimation of the minimum effective anisotropy magnitude of urban neighbourhoods as a function of building-height-to-spacing ratio, building plan area density, and shortwave irradiance. Finally, four \u201clocal climate zones\u201d are simulated at two latitudes. Removal of neighbourhood street orientation regularity for these zones decreases maximum anisotropy by 3%\u201331%. Furthermore, thermal and radiative material properties are a weaker predictor of anisotropy than neighbourhood morphology. This study is the first systematic evaluation of effective anisotropy magnitude and causation for urban landscapes.<\/jats:p>","DOI":"10.3390\/rs8020108","type":"journal-article","created":{"date-parts":[[2016,2,1]],"date-time":"2016-02-01T10:03:26Z","timestamp":1454321006000},"page":"108","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":96,"title":["Daytime Thermal Anisotropy of Urban Neighbourhoods: Morphological Causation"],"prefix":"10.3390","volume":"8","author":[{"given":"E.","family":"Krayenhoff","sequence":"first","affiliation":[{"name":"Department of Geography, Western University, London, ON N6A 5C2, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"James","family":"Voogt","sequence":"additional","affiliation":[{"name":"Department of Geography, Western University, London, ON N6A 5C2, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2016,1,30]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"471","DOI":"10.1177\/030913338801200401","article-title":"The urban energy balance","volume":"12","author":"ReferencesOke","year":"1988","journal-title":"Prog. Phys. Geogr."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"3084","DOI":"10.1080\/01431161.2012.716540","article-title":"Land surface emissivity retrieval from satellite data","volume":"34","author":"Li","year":"2013","journal-title":"Int. J. Remote Sens."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"370","DOI":"10.1016\/S0034-4257(03)00079-8","article-title":"Thermal remote sensing of urban climates","volume":"86","author":"Voogt","year":"2003","journal-title":"Remote Sens. Environ."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"335","DOI":"10.1016\/j.isprsjprs.2009.03.007","article-title":"Thermal infrared remote sensing for urban climate and environmental studies: Methods, applications, and trends","volume":"64","author":"Weng","year":"2009","journal-title":"ISPRS J. Photogram. Remote Sens."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"14","DOI":"10.1016\/j.rse.2012.12.008","article-title":"Satellite-derived land surface temperature: Current status and perspectives","volume":"131","author":"Li","year":"2013","journal-title":"Remote Sens. Environ."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"157","DOI":"10.1016\/0034-4257(94)00072-U","article-title":"Algorithms for extracting information from remote thermal-IR observations of the Earth\u2019s surface","volume":"51","author":"Norman","year":"1995","journal-title":"Remote Sens. Environ."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"895","DOI":"10.1080\/014311698215784","article-title":"Effects of urban surface geometry on remotely-sensed surface temperature","volume":"19","author":"Voogt","year":"1998","journal-title":"Int. J. Remote Sens."},{"key":"ref_8","unstructured":"Oke, T.R. (1987). Boundary Layer Climates, Routledge."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"167","DOI":"10.1016\/0168-1923(95)02260-5","article-title":"An experimental study of angular effects on surface temperature for various plant canopies and bare soils","volume":"77","author":"Lagouarde","year":"1995","journal-title":"Agric. For. Meteorol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"360","DOI":"10.1016\/S0034-4257(01)00183-3","article-title":"Directional effect on radiative surface temperature measurements over a semiarid grassland site","volume":"76","author":"Chehbouni","year":"2001","journal-title":"Remote Sens. Environ."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"11997","DOI":"10.1029\/2000JD900671","article-title":"Estimation of soil and vegetation temperatures with multiangular thermal infrared observations. IMGRASS, HEIFE and SGP 1997 experiments","volume":"106","author":"Menenti","year":"2001","journal-title":"J. Geophys. Res."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"4458","DOI":"10.1109\/TGRS.2011.2144604","article-title":"Directional effects on land surface temperature estimation from Meteosat Second Generation for savanna landscapes","volume":"49","author":"Rasmussen","year":"2011","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"169","DOI":"10.1016\/0034-4257(89)90016-3","article-title":"Modeling directional thermal radiance from a forest canopy","volume":"29","author":"McGuire","year":"1989","journal-title":"Remote Sens. Environ."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"17","DOI":"10.1016\/S0034-4257(99)00085-1","article-title":"Experimental study of brightness surface temperature angular variations of Maritime Pine (Pinus pinaster) stands","volume":"72","author":"Lagouarde","year":"2000","journal-title":"Remote Sens. Environ."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"16","DOI":"10.1016\/j.rse.2014.03.016","article-title":"Validation of remotely sensed surface temperature over an oak woodland landscape\u2014The problem of viewing and illumination geometries","volume":"148","author":"Ermida","year":"2014","journal-title":"Remote Sens. Environ."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"92","DOI":"10.1016\/S0034-4257(96)00165-4","article-title":"Satellite-view biases in retrieved surface temperatures in mountain areas","volume":"60","author":"Lipton","year":"1997","journal-title":"Remote Sens. Environ."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1117","DOI":"10.1175\/1520-0450(2000)039<1117:AOLSST>2.0.CO;2","article-title":"Anisotropy of land surface skin temperature derived from satellite data","volume":"39","author":"Minnis","year":"2000","journal-title":"J. Appl. Meteorol."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1941","DOI":"10.1109\/TGRS.2004.831886","article-title":"Directional effects in a daily AVHRR land surface temperature dataset over Africa","volume":"42","author":"Pinheiro","year":"2004","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"307","DOI":"10.1109\/TGRS.2007.905197","article-title":"Thermal land surface emissivity retrieved from SEVIRI\/Meteosat","volume":"46","author":"Trigo","year":"2008","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_20","first-page":"647","article-title":"Remote sensing of urban heat islands from environmental satellite","volume":"53","author":"Rao","year":"1972","journal-title":"Bull. Am. Meteorol. Soc."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1699","DOI":"10.1080\/01431168908904002","article-title":"Satellite-derived urban heat island from three coastal cities and the utilization of such data in urban climatology","volume":"10","author":"Roth","year":"1989","journal-title":"Int. J. Rem. Sens."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"199","DOI":"10.1016\/0378-7788(95)00945-0","article-title":"Development of a method to predict the heat island potential using remote sensing and GIS data","volume":"23","author":"Iino","year":"1996","journal-title":"Energy. Build."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"443","DOI":"10.1016\/j.rse.2003.12.011","article-title":"Airborne experimental measurements of the angular variations in surface temperature over urban areas: Case study of Marseille (France)","volume":"93","author":"Lagouarde","year":"2004","journal-title":"Remote Sens. Environ."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"226","DOI":"10.1016\/j.rse.2006.01.024","article-title":"Longwave radiation flux from an urban canopy: Evaluation via measurements of directional radiometric temperature","volume":"104","author":"Sugawara","year":"2006","journal-title":"Remote Sens. Environ."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"173","DOI":"10.1007\/s00703-008-0325-4","article-title":"Directional anisotropy in thermal infrared measurements over Toulouse city centre during the CAPITOUL measurement campaigns: First results","volume":"102","author":"Lagouarde","year":"2008","journal-title":"Meteorol. Atmos. Phys."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"87","DOI":"10.1016\/j.rse.2009.08.012","article-title":"Modelling daytime thermal infrared directional anisotropy over Toulouse city centre","volume":"114","author":"Lagouarde","year":"2010","journal-title":"Remote Sens. Environ."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"19","DOI":"10.1016\/j.rse.2011.06.022","article-title":"Experimental characterization and modelling of the nighttime directional anisotropy of thermal infrared measurements over an urban area: Case study of Toulouse (France)","volume":"117","author":"Lagouarde","year":"2012","journal-title":"Remote Sens. Environ."},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Voogt, J.A., and Soux, C.A. (2000, January 14\u201318). Methods for the assessment of representative urban surface temperatures. Proceedings of the 3rd Symposium on the Urban Environment (AMS), Davis, CA, USA.","DOI":"10.1080\/10106040008542160"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1891","DOI":"10.5194\/amt-8-2699-2015","article-title":"The effect of radiometer placement and view on inferred directional and hemispheric radiometric temperatures of a urban canopy","volume":"8","author":"Adderley","year":"2015","journal-title":"Atmos. Meas. Tech."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"1639","DOI":"10.1080\/014311698215153","article-title":"Visualisation of urban surface temperatures derived from satellite images","volume":"19","author":"Nichol","year":"1998","journal-title":"Int. J. Remote Sens."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"1117","DOI":"10.1175\/1520-0450(1997)036<1117:CUST>2.0.CO;2","article-title":"Complete urban surface temperatures","volume":"36","author":"Voogt","year":"1997","journal-title":"J. Appl. Meteorol."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"1679","DOI":"10.1175\/1520-0450-39.10.1679","article-title":"Modeling surface sensible heat flux using surface radiative temperatures in a simple urban area","volume":"39","author":"Voogt","year":"2000","journal-title":"J. Appl. Meteorol."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"1462","DOI":"10.1016\/j.rse.2010.01.025","article-title":"Estimating aerodynamic resistance of rough surfaces using angular reflectance","volume":"114","author":"Chappell","year":"2010","journal-title":"Remote Sens. Environ."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"433","DOI":"10.1007\/s10546-006-9153-6","article-title":"A microscale three-dimensional urban energy balance model for studying surface temperatures","volume":"123","author":"Krayenhoff","year":"2007","journal-title":"Bound.-Layer Meteorol."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"109","DOI":"10.1023\/B:BOUN.0000010995.62115.46","article-title":"A model to calculate what a remote sensor sees of an urban surface","volume":"112","author":"Soux","year":"2004","journal-title":"Bound.-Layer Meteorol."},{"key":"ref_36","unstructured":"Krayenhoff, E.S. (2005). A Microscale 3-D Urban Energy Balance Model for Studying Surface Temperatures. [Master\u2019s Thesis, Department of Geography, Western University]."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"482","DOI":"10.1016\/j.rse.2007.05.013","article-title":"Assessment of an urban sensor view model for thermal anisotropy","volume":"112","author":"Voogt","year":"2008","journal-title":"Remote Sens. Environ."},{"key":"ref_38","unstructured":"Voogt, J.A., and Krayenhoff, E.S. (2005, January 14\u201316). Modeling urban thermal anisotropy. Proceedings of the 5th International Symposium Remote Sensing of Urban Areas, Phoenix, AZ, USA."},{"key":"ref_39","unstructured":"Krayenhoff, E.S., and Voogt, J.A. (2007, January 10\u201313). Combining sub-facet scale urban energy balance and sensor-view models to investigate effective thermal anisotropy on city structure. Proceedings of the 7th Symposium on the Urban Environment, American Meteorological Society, San Diego, CA, USA."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"197","DOI":"10.1007\/s00704-012-0616-z","article-title":"An urban neighborhood temperature and energy study from the CAPITOUL experiment with the SOLENE model","volume":"110","author":"Henon","year":"2012","journal-title":"Theor. Appl. Climatol."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"1879","DOI":"10.1175\/BAMS-D-11-00019.1","article-title":"Local climate zones for urban temperature studies","volume":"93","author":"Stewart","year":"2012","journal-title":"Bull. Am. Meteorol. Soc."},{"key":"ref_42","unstructured":"Ashdown, I. (1994). Radiosity: A Programmers Perspective, John Wiley & Sons."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"229","DOI":"10.1007\/BF00863615","article-title":"An urban canopy-layer climate model","volume":"57","author":"Mills","year":"1997","journal-title":"Theor. Appl. Climatol."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"1011","DOI":"10.1175\/1520-0450(2002)041<1011:EOTTEB>2.0.CO;2","article-title":"Evaluation of the town energy balance (TEB) scheme with direct measurements from dry districts in two cities","volume":"41","author":"Masson","year":"2002","journal-title":"J. Appl. Meteorol."},{"key":"ref_45","unstructured":"Kurz, B. (2009). Modelisation De L\u2019anisotropie Directionelle de la Temperature de Surface: Application au Cas de Milieu Forestiers et Urbains. [Ph.D. Thesis, University of Toulouse]."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"231","DOI":"10.1007\/s00704-004-0117-9","article-title":"BUBBLE\u2014An urban boundary layer meteorology project","volume":"81","author":"Rotach","year":"2005","journal-title":"Theor. Appl. Climatol."},{"key":"ref_47","unstructured":"Iqbal, M. (1983). An Introduction to Solar Radiation, Academic Press."},{"key":"ref_48","first-page":"1127","article-title":"A new long-wave formula for estimating downward clear-sky radiation at the surface","volume":"122","author":"Prata","year":"1996","journal-title":"Q. J. R. Meteorol. Soc."},{"key":"ref_49","unstructured":"Stull, R.B. (2000). Meteorology for Scientists and Engineers, Brooks\/Cole. [2nd ed.]."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"103","DOI":"10.1016\/0378-7788(88)90026-6","article-title":"Street design and urban canopy layer climate","volume":"11","author":"Oke","year":"1988","journal-title":"Energy Build."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"D06114","DOI":"10.1029\/2010JD014613","article-title":"Temporal patterns of thermal emission directionality of crop canopies","volume":"116","author":"Huang","year":"2011","journal-title":"J. Geophys. Res."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"1062","DOI":"10.1002\/joc.3746","article-title":"Evaluation of the local climate zone scheme using temperature observations and model simulations","volume":"34","author":"Stewart","year":"2014","journal-title":"Int. J. Climatol."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"1634","DOI":"10.1175\/2010JAMC2356.1","article-title":"Impacts of urban albedo increase on local air temperature at daily-annual time scales: Model results and synthesis of previous work","volume":"49","author":"Krayenhoff","year":"2010","journal-title":"J. Appl. Meteorol. Climatol."},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"33","DOI":"10.1016\/0034-4257(83)90026-3","article-title":"Remote sensing of row crop structure and component temperatures using directional radiometric temperatures and inversion techniques","volume":"13","author":"Kimes","year":"1983","journal-title":"Remote Sens. Environ."},{"key":"ref_55","unstructured":"Dyce, D.R. (2014). A Sensor View Model to Investigate the Influence of Tree Crowns on Effective Urban Thermal Anisotropy. [Master\u2019s Thesis, Department of Geography, Western University]."},{"key":"ref_56","unstructured":"Dyce, D.R., and Voogt, J.A. (2015, January 20\u201324). The influence of tree crowns on effective urban thermal anisotropy. Proceedings of the ICUC9\u20149th International Conference on Urban Climate\/12th Symposium on the Urban Environment, Toulouse, France."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/8\/2\/108\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T19:18:35Z","timestamp":1760210315000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/8\/2\/108"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2016,1,30]]},"references-count":56,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2016,2]]}},"alternative-id":["rs8020108"],"URL":"https:\/\/doi.org\/10.3390\/rs8020108","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2016,1,30]]}}}