Abstract
Canopy-level humidity is often less at night during fine weather in a mid-latitude city, compared to its rural surroundings. This feature has been attributed, in part, to reduced urban dew, but links are largely unproven, because urban dew data are rare. In this study, surface moisture (i.e., dew + guttation by blotting) and dewfall (by mini-lysimeter) were measured at rural and urban residential sites in Vancouver, Canada, during the summer of 1996. Air temperature and humidity were measured at both sites, and on rural-to-urban vehicle traverses. Weather and location effects were evident. Humidity data suggested the small (< 1 g m−3) urban moisture excess observed on fine nights was linked to reduced urban dew. For grass, the frequency of moisture events, and surface moisture amounts, were similar for both sites. However, on grass, rural dewfall (mean=0.10 mm per night) was more than urban dewfall (mean=0.07 mm per night). On the other hand, data for a ‘roof’ lysimeter (mean dewfall=0.12 mm per night) showed that an urban roof could rival rural grass as a favoured location for dewfall in Vancouver.
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References
B. Ackerman (1987) ArticleTitle‘Notes. Climatology of Chicago Area Urban–Rural Differences in Humidity’ J. Clim. Appl. Meteorol 26 427–430
Chamberlain, N.: 2004, ‘GPS/Loran Atmospheric Sounding System (GLASS)’, web page of the National Center for Atmospheric Research (NCAR), Atmospheric Technology Division, Boulder, CO. www.atd.ucar.edu/rtf/facilities/class/class.html. Accessed on 26 February 2004.
B. G. Collins (1961) ArticleTitle‘A Standing Dew Meter’ Meteorol. Mag 90 114–117
J. R. Garratt M. Segal (1988) ArticleTitle‘On the Contribution of Atmospheric Moisture to Dew Formation’ Boundary-Layer Meteorol 45 209–236
C. S. B. Grimmond T. R. Oke (1991) ArticleTitle‘An Evapotranspiration–Interception Model for Urban Areas’ Water Resour. Res 27 1739–1755
C. S. B. Grimmond T. R. Oke (2000) ‘Variability of Evapotranspiration Rates in Urban Areas’ R. J. de Dear J. D. Kalma T. R. Oke A. Auliciems (Eds) Biometeorology and Urban Climatology at the Turn of the Millennium. Selected Papers from the Conference ICB-ICU’99 World Meteorological Organisation Geneva 475–480
C. S. B. Grimmond S. A. Isard M. J. Belding (1992) ArticleTitle‘Development and Evaluation of Continuously Weighing Mini-lysimeters’ Agric. For. Meteorol 62 205–218
K. D. Hage (1975) ArticleTitle‘Urban–Rural Humidity Differences’ J. Appl. Meteorol 14 1277–1283
R. N. Hughes P. Brimblecombe (1994) ArticleTitle‘Dew and Guttation: Formation and Environmental Significance’ Agric. For. Meteorol 67 173–190
G. J. Kidron A. Yair A. Danin (2000) ArticleTitle‘Dew Variability Within a Small Arid Drainage Basin in the Negev Highlands, Israel’ Quart. J. Roy. Meteorol. Soc 126 63–80
D. O. Lee (1991) ArticleTitle‘Urban–Rural Humidity Differences in London’ Int. J. Climatol 11 577–582
W. H. Luo J. Goudriaan (2000) ArticleTitle‘Dew Formation on Rice under Varying Durations of Nocturnal Radiative Loss’ Agric. For. Meteorol 104 303–313
V. Masson (2000) ArticleTitle‘A Physically Based Scheme for the Urban Energy Budget in Atmospheric Models’ Boundary-Layer Meteorol 94 357–397
Mattsson, J. O.: 1979, Introduktion till Mikro-och Lokalklimatologin (Introduction to Micro- and Local Climatology), Liber Läromedel, Malmö, Sweden, 201 pp. (Translated by J. O. Mattsson).
J. L. Monteith (1957) ArticleTitle‘Dew’ Quart. J. Roy. Meteorol. Soc 83 322–341
P. A. Mulawa S. H. Cadle F. Lipari C. C. Ang R. T. Vandervennet (1986) ArticleTitle‘Urban Dew: Its Composition and Influence on Dry Deposition Rates’ Atmos. Environ 20 1389–1396
Myers, T. M.: 1974, Dew as a Visual Indicator of the Urban Heat Island of Washington, DC. M.Sc. Thesis, University of Maryland, Maryland, 54 pp
T. R. Oke (1987) Boundary-Layer Climates Routledge London 435
Oke, T. R. and Hay, J.: 1994, The Climate of Vancouver, 2nd edn., B.C. Geographical Series, No. 50, University of British Columbia, Vancouver, Canada, 84 pp
T. R. Oke G. B. Maxwell (1975) ArticleTitle‘Urban Heat Island Dynamics in Montreal and Vancouver’ Atmos. Environ 9 191–200
Oke, T. R., Grimmond, C. S. B., and Spronken-Smith, R. A.: 1998, ‘On the Confounding Role of Rural Wetness in Assessing Urban Effects on Climate’, in preprint, 2nd Urban Environment Symposium, Albuquerque, NM, November 2–6, 1998, American Meterological Society, 45 Beacon St., Boston, MA, pp59–62.
H. Okochi T. Kajimoto Y. Arai M. Igawa (1996) ArticleTitle‘Effect of Acid Deposition on Urban Dew Chemistry in Yokohama, Japan’ Bull. Chem. Soc. Japan 69 3355–3365
K. Richards (2004) ArticleTitle‘Observation and Simulation of Dew in Rural and Urban Environments’ Prog. Phys. Geog 28 76–94
K. Richards T. R. Oke (2002) ArticleTitle‘Validation and Results of a Scale Model of Dew Deposition in Urban Environments’ Int. J. Climatol 22 1915–1933
K. E. Runnalls T. R. Oke (2000) ArticleTitle‘Dynamics and Controls of the Near-Surface Heat Island of Vancouver, British Columbia’ Phys. Geog 21 283–304
L. J. Schroder T. C. Willoughby R. B. See B. A. Malo (1989) ‘The Chemical Composition of Precipitation, Dew and Frost, and Fog in Denver, Colorado’ J. W. Delleur (Eds) Atmospheric Deposition IAHS Publication No. 179, Baltimore, U.S.A. 83–90
M. L. Sharma (1976) ArticleTitle‘Contribution of Dew to the Hydrologic Balance of a Semi-Arid Grassland’ Agric. Meteorol 17 321–331
R. A. Spronken-Smith T. R. Oke (1999) ArticleTitle‘Scale Modelling of Nocturnal Cooling in Urban Parks’ Boundary-Layer Meteorol 93 287–312
D. G. Steyn (1980) ArticleTitle‘Research Note. The Calculation of View Factors from Fisheye-Lens Photographs’ , Atmos. Ocean 18 254–258
D. G. Steyn T. J. Lyons (1985) ArticleTitle‘Comments on the Determination of View Factors in Urban Canyons’ J. Clim. Appl. Meteorol 24 383–385
R. A. Sudmeyer R. A. Nulsen W. D. Scott (1994) ArticleTitle‘Measured Dewfall and Potential Condensation on Grazed Pasture in the Collic River Basin, Southwestern Australia’ J. Hydrol 154 255–269
G. H. Wagner K. F. Steele M. E. Peden (1992) ArticleTitle‘Dew and Frost Chemistry at a Midcontinent Site, United States’ J. Geophys. Res 97 IssueIDD18 20591–20597
A. Weiss D. L. Lukens (1981) ArticleTitle‘Electronic Circuit for Detecting Leaf Wetness and Comparison of Two Sensors’ Plant Dis 65 41–43
K. -P. Wittich (1995) ArticleTitle‘Some Remarks on Dew Duration on Top of an Orchard’ Agric. For. Meteorol 72 167–180
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Richards, K. Urban and rural dewfall, surface moisture, and associated canopy-level air temperature and humidity measurements for vancouver, canada. Boundary-Layer Meteorol 114, 143–163 (2005). https://doi.org/10.1007/s10546-004-8947-7
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DOI: https://doi.org/10.1007/s10546-004-8947-7