Impact of vegetation on rooftop temperatures under a modular green roof system

Texas A&M has a three college multidisciplinary project focused on undergraduate education and research on green roof and living wall technologies. These roof and wall plots of living plant material are increasingly used to reduce energy costs in buildings. The Atmospheric Science/Meteorology role in the project is primarily the instrumentation of the various plots and living walls for standard meteorological variables as well as soil and rooftop temperatures, soil moisture, and radiation. In early fall of 2015, a temporary “fallow” (bare) period in one of the primary plots provided a unique opportunity to assess the contribution of the adapted vegetation in the remaining plot to lower temperatures of the underlying rooftop. The 3 x 3 rooftop temperature sensor arrays under each plot are compared along with ancillary data such as air temperature and solar radiation. We examine these data for indications of the value of the vegetation in reducing daytime rooftop temperatures in varying ambient temperature and cloud cover conditions. We will also examine pre-fallow periods for possible impact of differing vegetation regimes and for temperature differences between the two primary plots which may be unrelated to vegetation.