Effects of Local-Scale Land Cover Changes on Characteristics of Urban Atmosphere: A Case Study of the City of Phoenix
Abstract
Clear understanding the interactions between the Earth's surface and the overlying atmosphere is very challenging. Land-atmosphere interactions vary depending on surface properties associated with land cover and land use. In urban areas, the surface experiences change due to human development activities, and then the changed surface could modify weather and climate. Accurate information of the surface condition change, particularly for the change into an urbanized surface from natural landscape could be critical for atmospheric modeling. This study focuses on the effects of the urbanized surface at Phoenix, Arizona on the atmosphere.
We performed the numerical simulations with the framework of large eddy simulation (LES)-within-mesoscale model (MM) using the Weather Research and Forecasting (WRF) model version 3.9. Specifically, the framework has three domains with the grid spacing of 1 km, 333 m, and 111 m. The LES domains at 333 m and 111 m employ the turbulence kinetic energy (TKE) sub-grid closure turning off the atmospheric boundary layer scheme. Background atmospheric conditions on scales larger than the size of the largest domain are provided as the initial and lateral boundary conditions from the National Centers for Environmental Prediction (NCEP) Global Forecast System (GFS) 0.25-degree data sets. NLCD 30-m land cover data sets are used. The land cover change over the decade is considered with the datasets of 2006, 2011 and 2016. For terrain and vegetation fraction, we use 900-m resolution data sets. In the 2016 land cover dataset compared with in the 2006 dataset, the low intensity urban area is increased by 16 %, and the high intensity urban area by 255 %. The grass land is decreased by 97 %, and the evergreen forests by 2.7 %. The WRF simulation results are validated with the Automated Surface Observing System (ASOS) data in terms of 1-min time series of surface temperature, pressure, dewpoint temperature, precipitation, and wind speed and direction, and radiosonde soundings from Integrated Global Radiosonde Archive (IGRA). In order to examine the effect of the urbanized surface, we select the two fair-weather days on 6 February and 12 August in 2018. We checked the results by changing the land cover type.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMGC21D1323C
- Keywords:
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- 1622 Earth system modeling;
- GLOBAL CHANGE;
- 1631 Land/atmosphere interactions;
- GLOBAL CHANGE;
- 1632 Land cover change;
- GLOBAL CHANGE;
- 1655 Water cycles;
- GLOBAL CHANGE