The National Research Council (2012) identified the urban boundary layer as “the most understudied and undersampled layer in the urban atmosphere” due to difficulty of access. Unmanned aircraft systems (UAS) are capable of collecting meteorological data to characterize the evolution of temperature, humidity, and winds within the boundary layer, as well as estimate the turbulent sensible, latent, and momentum fluxes, longwave and shortwave radiation, and skin temperature (Knuth et al. 2013). Provided they are safely integrated into the national airspace over the next several years, UAS could serve a new method to collect data to characterize both the
urban and surrounding rural boundary layer and surface characteristics without installing several large towers across a metropolitan area.
Grimmond et al. (2010) found that urban energy balance models have the least capability to model latent heat fluxes. Given that humid heat waves have a stronger impact on human health (Guirguis et al. 2014), future research in urban canopy model development should focus on improving the modeling of latent heat fluxes through better integration of urban vegetation. While a tile approach works for cities where irrigation is not a significant source of moisture, it does not allow direct interaction of built and vegetated surfaces or the capability to account for external water sources such as street cleaning.
Future research should also focus on creating urban canopy parameter datasets. The lack of information on some urban canopy parameters has resulted in tuning the parameter to minimize differences between predicted and observed variables. The National Urban Database with Access Portal’s gridded urban parameter datasets for 44 cities was included in the recent release of the WRF model version 3.5 for use with both the single-layer and multi-layer urban canopy models. However, limitations exist with respect to urban fraction.
A significant need exists for two-way interactions between urban meteorologists and end user communities (e.g., emergency managers, public utilities, and urban planners) to better understand user information needs and steer the direction of urban meteorological research. Coordination with state programs experienced in extension, education, and outreach at the local level, such as Land Grant and Sea Grant Extension
or OK-First, could help identify user groups and initiate and facilitate ongoing dialogue. To sustain this effort in the long term and ensure research is socially relevant to end users will require an interdisciplinary team of both physical and social scientists that speak the same language.
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