Assessment of High Resolution Urbanized Meteorological Models using ground based remote sensing and satellite imagery

As urbanization continues to increase at significant rates, the ability to account for high resolution forecasts must critically account for the complex urban land surface as well as the modifications in heat exchange due to urban building energy use. It is not surprising that research efforts in this area have resulted in “exotic” models to take into account more intricate features of the urban heat exchange. Unfortunately, this activity has not been guided by substantial validation efforts. It is clear that direct validation at the surface is extraordinarily difficult since micro structures including shading can dramatically inhibit such approaches. On the other hand, vertical profiling sensors which can probe near the building tops should be able to provide a unique validation approach to assess both qualitative and quantitative aspects of urbanized WRF models. In this presentation, we make use of a unique Microwave Radiometer (MWR) to provide vertical profiling of temperature and water vapour within the urban canopy. This system can provide vertical resolution profiling at 50 meter resolution. To support this instrument, we will use multiple launch radiosondes collocated with the MWR to assess performance. In addition, one of the most complex issues is the extent of cloud formation. We will make use of a combination of a TSI Hemispherical Imager as well as lidar based cloud bases to calibrate the imager to provide useful cloud fraction metrics which can be compared to both the model outputs as well as satellite cloud fraction estimates. One particular focus of our comparisons is the study of model performance as the resolution increases from the baseline 12km value to 1km. In particular, we find that these models can be unstable if the resolution is pushed down top much. Details of temperature, water vapour and Planetary Boundary Layer which is validated against lidar will be presented for summer 2013 for the different resolutions.