Abstract
In this study, urban climate in Nanjing of eastern China is simulated using 1-km resolution Weather Research and Forecasting (WRF) model coupled with a single-layer Urban Canopy Model. Based on the 10-summer simulation results from 2000 to 2009 we find that the WRF model is capable of capturing the high-resolution features of urban climate over Nanjing area. Although WRF underestimates the total precipitation amount, the model performs well in simulating the surface air temperature, relative humidity, and precipitation frequency and inter-annual variability. We find that extremely hot events occur most frequently in urban area, with daily maximum (minimum) temperature exceeding 36°C (28°C) in around 40% (32%) of days. Urban Heat Island (UHI) effect at surface is more evident during nighttime than daytime, with 20% of cases the UHI intensity above 2.5°C at night. However, The UHI affects the vertical structure of Planet Boundary Layer (PBL) more deeply during daytime than nighttime. Net gain for latent heat and net radiation is larger over urban than rural surface during daytime. Correspondingly, net loss of sensible heat and ground heat are larger over urban surface resulting from warmer urban skin. Because of different diurnal characteristics of urban-rural differences in the latent heat, ground heat and other energy fluxes, the near surface UHI intensity exhibits a very complex diurnal feature. UHI effect is stronger in days with less cloud or lower wind speed. Model results reveal a larger precipitation frequency over urban area, mainly contributed by the light rain events (< 10 mm d−1). Consistent with satellite dataset, around 10–20% more precipitation occurs in urban than rural area at afternoon induced by more unstable urban PBL, which induces a strong vertical atmospheric mixing and upward moisture transport. A significant enhancement of precipitation is found in the downwind region of urban in our simulations in the afternoon.
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References
Bornstein, R. D., 1968: Observations of the urban heat island effects in New York City. J. Appl. Meteorol., 7, 575–582.
Braham, R. R., 1979: Comments on “Urban, topographic and diurnal effects on rainfall in the St. Louis region”. J. Appl. Meteorol., 18, 371–374.
Bukovsky, M. S., and D. J. Karoly, 2009: Precipitation simulations using WRF as a nested regional climate model. J. Appl. Meteor. Climatol., 48, 2152–2159, doi:10.1175/2009JAMC2186.1.
Burian, S. J., and J. M. Shepherd, 2005: Effects of urbanization on the diurnal rainfall pattern in Houston. Hydrol. Process, 19, 1089–1103.
Changnon, S. A., R. G. Semonin, and F. A. Huff, 1976: A hypothesis for urban rainfall anomalies. J. Appl. Meteorol., 15, 544–560.
Chen, F., and J. Dudhia, 2001: Coupling an advanced land-surface/hydrology model with the Penn State/NCAR MM5 modeling system. Part I: Model description and implementation. Mon. Wea. Rev., 129, 569–585.
—, M. Tewari, H. Kusaka, and T. T. Warner, 2006: Current status of urban modeling in the community Weather Research and Forecast (WRF) model. Joint with Sixth Symposium on the Urban Environment and AMS Forum on Managing our Physical and Natural Resources: Successes and Challenges, Atlanta, GA, USA. Amer. Meteor. Soc., CDROM. J1.4.
Chin, H.-N. S., M. J. Leach, G. A. Sugiyama, J. M. Leone, H. Walker, J. S. Nasstrom, and M. J. Brown, 2005: Evaluation of an urban canopy parameterization in a mesoscale model using VTMX and URBAN 2000 data. Mon. Wea. Rev., 133, 2043–2068.
Clarke, J. F., 1969: Nocturnal urban boundary layer over Cincinnati, Ohio. Mon. Wea. Rev., 97, 582–589.
Coutts, A. M., J. Beringer, and N. J. Tapper, 2007: Impact of increasing urban density on local climate: Spatial and temporal variation in the surface energy balance in Melbourne, Australia. J. Appl. Meteor. Climatol., 46, 477–493.
Grimmond, C. S. B, and Coauthors, 2010: The International Urban Energy Balance Models Comparison Project: First Results from Phase 1. J. Appl. Meteor. Climatol., 49, 1268–1292.
—, and Coauthors, 2011: Initial results from Phase 2 of the international urban energy balance model comparison. Int. J. Climatol., 31, 244–272.
Hamdi, R., A. Deckmyn, P. Termonia, G. R. Demarée, P. Baguis, S. Vanhuysse, and E. Wolff, 2009: Effects of historical urbanization in the Brussels Capital region on surface air temperature time series: A model study. J. Appl. Meteor. Climatol., 48, 2181–2196.
Hand, L. M., and J. M. Shepherd, 2009: An investigation of warm-season spatial rainfall variability in Oklahoma City: Possible linkages to urbanization and prevailing wind. J. Appl. Meteor. Climatol., 48, 251–269.
Holt, T., and J. Pullen, 2007: Urban canopy modeling of the New York City metropolitan area: A comparison and validation of single- and multilayer parameterizations. Mon. Wea. Rev., 135, 1906–1930.
Hong, S.-Y., and J.-O. J. Lim, 2006: The WRF single-moment 6-class microphysics scheme (WSM6). J. Korean Meteor. Soc., 42, 129–151.
—, J. Dudhia, and S.-H. Chen, 2004: A revised approach to ice microphysical processes for the bulk parameterization of clouds and precipitation. Mon. Wea. Rev., 132, 103–120.
—, Y. Noh, and J. Dudhia, 2006: A new vertical diffusion package with an explicit treatment of entrainment processes. Mon. Wea. Rev., 134, 2318–2341.
Huang, L., H. Huang, D. Xiang, J. Zhu, and J. Li, 2007: The diurnal change of air temperature in four types of land cover and urban heat island effect in Nanjing, China (in Chinese). Ecology and Environment, 16, 1411–1420.
Huffman, G. J., and Coauthors, 2007: The TRMM Multisatellite Precipitation Analysis (TMPA): Quasi-global, multiyear, combined-sensor precipitation estimates at fine scales. J. Hydrometeor., 8, 38–55.
Inoue, T., and F. Kimura, 2004: Urban effects on low-level clouds around the Tokyo metropolitan area on clear summer days. Geophys. Res. Lett., 31, L05103, doi:10.1029/2003GL018908.
Jones, P. D., P. M. Kelly, and C. M. Goodess, 1989: The effect of urban warming on the northern hemisphere temperature average. J. Climate, 2, 285–290.
Kain, J. S., 2004: The Kain-Fritsch convective parameterization: An update. J. Appl. Meteorol., 43, 170–181.
Khemani, L. T., and B. V. Ramana Murty, 1973: Rainfall variations in an urban industrial region. J. Appl. Meteorol., 12, 187–194.
Kim, Y.-H., and J.-J. Baik, 2005: Spatial and temporal structure of the urban heat island in Seoul. J. Appl. Meteorol., 44, 591–605, doi:10.1175/JAM2226.1.
Kusaka, H., and F. Kimura, 2004a: Coupling a single-layer urban canopy model with a simple atmospheric model: Impact on urban heat island simulation for an idealized case. J. Meteor. Soc. Japan, 82, 67–80.
—, and —, 2004b: Thermal effects of urban canyon structure on the nocturnal heat island: Numerical experiment using a mesoscale model coupled with an urban canopy model. J. Appl. Meteorol., 43, 1899–1910.
—, H. Kondo, Y. Kikegawa, and F. Kimura, 2001: A simple singlelayer urban canopy model for atmospheric models: Comparison with multi-layer and slab models. Bound.-Layer Meteor., 101, 329–358.
—, F. Kimura, K. Nawata, T. Hanyu, and Y. Miya, 2009: The chink in the armor: Questioning the reliability of conventional sensitivity experiments in determining urban effects on precipitation patterns. proc., 7th International Conference for urban Climate, Yokohama, Japan, Tokyo Institute of Technology, B12-2.
—, T. Takata, and Y. Takane, 2010: Reproducibility of regional climte in central Japan using the 4-km resolution WRF model. SOLA, 6, 113–116, doi:10.2151/sola.2010-029.
Martilli, A., 2002: Numerical study of urban impact on boundary layer structure: Sensitivity to wind speed, urban morphology, and rural soil moisture. J. Appl. Meteorol., 41, 1247–1266.
Masson, V., 2000: A physically-based scheme for the urban energy budget in atmospheric models. Bound.-Layer Meteor., 94, 357–397.
Miao, S., F. Chen, M. A. Lemone, M. Tewari, Q. Li, and Y. Wang, 2009: An observational and modeling study of characteristics of urban heat island and boundary layer structures in Beijing. J. Appl. Meteor. Climatol., 48, 484–501.
Mote, T. L., M. C. Lacke, and J. M. Shepherd, 2007: Radar signatures of the urban effect on precipitation distribution: A case study for Atlanta, Georgia. Geophys. Res. Lett., 34, L20710, doi:10.1029/2007GL031903.
Oke, T. R., 1981: Canyon geometry and the nocturnal urban heat island: Comparison of scale model and field observations. Int. J. Climatol., 1, 237–254.
—, 1982: The energetic basis of the urban heat island. Quart. J. Roy. Meteor. Soc., 108, 1–24.
Oleson, K. W., G. B. Bonan, J. Feddema, and M. Vertensten, 2008: An urban parameterization for a global climate model. Part II: Sensitivity to input parameters and the simulated urban heat island in offline simulations. J. Appl. Meteor. Climatol., 47, 1061–1076.
Ren, G., Y. Zhou, Z. Chu, J. Zhou, A. Zhang, J. Guo, and X. Liu, 2008: Urbanization effects on observed surface air temperature trends in north China. J. Climate, 21, 1333–1348.
Roy, S. S., and F. Yuan, 2009: Trends in extreme temperatures in relation to urbanization in the twin cities Metropolitan area, Minnesota. J. Appl. Meteor. Climatol., 48, 669–679.
Shepherd, J. M., 2005: A review of current investigations of urban-induced rainfall and recommendations for the future. Earth Interact., 9, 1–27. [Available online at http://EarthInteractions.org.]
Shou, Y.-X., and D.-L. Zhang, 2010: Impact of environment flows on the daytime urban boundary layer structures over the Baltimore metropolitan region. Atmos. Sci. Lett., 11, 1–6.
Shreffler, J. H., 1978: Detection of centripetal heat-island circulations from tower data in St. Louis. Bound.-Layer Meteor., 15, 229–242.
Skamarock, W. C., J. B. Klemp, J. Dudhia, D. O. Gill, D. M. Barker, M. G. Duda, X-Y. Huang, W. Wang, and J. G. Powers, 2008: A Description of the Advanced Research WRF Version 3, NCAR Technical Note, NCAR/TN-475+STR, 123 pp.
Souch, C., and S. Grimmond, 2006: Applied climatology: Urban climate. Prog. Phys. Geog., 30, 270–279.
Tewari M., F. Chen, H. Kusaka, and S. Miao, 2007: Coupled WRF/Unied Noah/urban-canopy modeling system. NCAR WRF Documentation, NCAR, Boulder, 1–22.
Thanh Ca, V., Y. Ashie, and T. Asaeda, 2002: A k-ɛ turbulence closure model for the atmospheric boundary layer including urban canopy. Bound.-Layer Meteor., 102, 459–490.
Trusilova, K., M. Jung, and G. Churkina, 2009: On climate impacts of a potential expansion of urban land in Europe. J. Appl. Meteor. Climatol., 48, 1971–1980.
Uno, I., S. Wakamatsu, H. Ueda, and A. Nakamura, 1988: An observational study of the structure of the nocturnal urban boundary layer. Bound.-Layer Meteor., 45, 59–82.
World Resources Institute, 1996: World Resources 1996-97: The urban environment. World Resources Institute, 400 pp. [Available online at http://www.wri.org/publication/world-resources-1996-97-urbanenvironment.]
Yu, R., T. Zhou, A. Xiong, Y. Zhu, and J. Li, 2007: Diurnal variations of summer precipitation over contiguous China. Geophys. Res. Lett., 34, L01704, doi:10.1029/2006GL028129.
Zhou, T., R. Yu, H. Chen, A. Dai, Y. Pan, 2008: Summer Precipitation Frequency, Intensity, and Diurnal Cycle over China: A Comparison of Satellite Data with Rain Gauge Observations. J. Climate, 21, 3997–4010.
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Yang, B., Zhang, Y. & Qian, Y. Simulation of urban climate with high-resolution WRF model: A case study in Nanjing, China. Asia-Pacific J Atmos Sci 48, 227–241 (2012). https://doi.org/10.1007/s13143-012-0023-5
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DOI: https://doi.org/10.1007/s13143-012-0023-5