Remote Sensing of Boundary Layer Thermodynamics and Wind

In the last century, systematic use of twice daily radiosondes has totally changed meteorology and especially weather forecasting. Meteorologists have developed a wide variety of forecast tools and indices derived from radiosonde soundings and have applied them to local weather forecasting. The radiosonde data are also assimilated into numerical weather models but their cost remains a major challenge for national weather services. In addition, the temporal resolution of radiosonde soundings is typically inadequate for many high impact local weather forecast applications. After several decades of research and development, commercially mature remote sensors are increasingly used for operational meteorology because they provide continuous temperature and humidity soundings in all weather conditions with radiosonde-equivalent observation accuracy, and unique liquid profiles [1]. These passive sensors detect microwave and infrared radiation emitted by atmospheric oxygen, water vapor and liquid water in multiple channels. Doppler lidars measure wind speed and direction by emitting short pulses of light (usually in the near-infrared band) and receive the Doppler shifted backscatter from atmospheric particles. Independent studies validate equivalent observation accuracy for Doppler lidars, radiosondes and wind profiling radars [2]. When combined, thermodynamic and Doppler lidar profilers provide continuous thermodynamic observations to 10km, and wind observations in the boundary layer. This combination of remote sensors delivers continuously updated forecast indices. This information is essential for accurate local high impact weather forecasting [3]. We present case studies based on collocated Doppler lidar and thermodynamic profiler observations during spring and summer 2012, at Boulder, Colorado.