Measurement performance assessment of future space-borne doppler wind lidar for numerical weather prediction

Global wind profile observation is important to improve initial conditions for numerical weather prediction (NWP), general circulation model, and various other meteorological studies. A spaceborne Doppler wind lidar (DWL) is one of promising remote sensing techniques for global wind measurement. We describe a study based on simulated satellite measurements for assessing the measurement performances of a Japanese coherent DWL. Global simulations are performed using pseudo-truth atmospheric model of an observing system simulation experiment (OSSE) conducted using the global NWP system of the Japan Meteorological Agency. Wind profile retrieval simulations have been performed for 1 month (August, 2010) and the results show that the percentage of good quality estimates is 40% below 8 km, and it decreases to 10% at 8-20 km in the southern hemisphere and is 20-50% in the northern hemisphere. Expected line-of-sight wind speed errors for good quality estimates are 0.5 m s-1 below 8 km and 1.1 m s^-1 at 8-20 km. In the future, the simulated observations will be used in the OSSE to quantitatively infer the potential impacts on NWP accuracy. To illustrate such analysis, results are shown from an initial validation test using a simple wind measurement model instead of the realistic DWL simulations.