Novel Deployment of Mobile Eddy Covariance Tower Observations Across Variations in the Built Environment in a Desert Urban Area
Technical Report,01 Jan 2015,30 Sep 2015
ARIZONA STATE UNIV TEMPE TEMPE United States
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A mobile eddy covariance tower platform is used to analyze water and energy fluxes over three unique urban land cover representations on the Arizona State University campuses 1 xeric landscape gravel cover and palo verde trees with drip-irrigation systems near tall buildings 2 high-density urban site asphalt-paved parking lot near a high-traffic intersection and 3 suburban mesic landscape turf grass with sprinkler irrigation in a residential neighborhood. The footprints associated with the eddy covariance flux measurements are determined and image analysis allows for land cover classification of each source area. The xeric site and high-density urban site behave like a semiarid landscape, with high Bowen ratios 3 and 8 respectively and higher sensible heat fluxes. The mesic site behaves more similarly to a grassland, with a Bowen ratio of 0.5 and latent heat flux greater than sensible heat flux. Precipitation events affects latent heat flux at the xeric site, while the high-density urban site appears to be relatively insensitive to precipitation input. Differences are observed in evaporative fraction, Bowen ratio, and the ratios of sensible heat and latent heat to the available energy when comparing wet days to dry days. There is also a difference observed when only rainfall events occurring during the day-time are considered, suggesting the timing of precipitation influences the urban surface energy and water balances. This analysis improves our understanding of energy and water fluxes over desert urban land covers and provides a framework for future assessments.
- Civil Engineering
- Structural Engineering and Building Technology
- Atmospheric Physics