Retrieval of wind temperature and pressure from single Doppler radar and a numerical model

A 4D data assimilation algorithm to obtain 3D wind and thermodynamic fields from radial velocities and a numerical model is derived. It is a blend of the continuous updating technique of Charney et al. (1969) and a diagnostic pressure and temperature retrieval technique suggested by Gal-Chen (1978). This model is tested only against model-generated data which are viewed as 'data observed from a real atmosphere'. A thermal bubble developing in a dry, neutral environment is simulated. The thermal recovery technique is found to be a necessary procedure to obtain successful data assimilation results. The present assimilation method is found to be capable of reducing the 'observational error' and making the assimilation run converge toward the control run. Without data insertion, errors in the nonobserved wind component are large.