Abstract: With improved assimilation techniques, it is now possible to directly assimilate cloud-cleared radiances, rather than temperature and moisture retrievals, in objective analyses. The direct use of the cloud-cleared radiances ...

Abstract: The relations between nonlinear energy transport and helicity of the flow are studied through simulations of thermal convection with mean shear. Parallel-plate convection with a rotating mean shear, a linear undirectional ...

Abstract: In this study, a global three-dimensional variational analysis system is formulated in model grid space. This formulation allows greater flexibility (e.g., inhomogeneity and anisotropy) for background error statistics. A ...

Abstract: t the National Centers for Environmental Prediction, the global ensemble forecasts from the ensemble Kalman filter scheme in the Global Forecast System are applied in a regional three-dimensional (3D) and a four dimensional ...

Abstract: The errors in the first-guess (forecast field) of an analysis system vary from day to day, but, as in all current operational data assimilation systems, forecast error covariances are assumed to be constant in time in the ...

Abstract: At the National Centers for Environmental Prediction (NCEP), a new three-dimensional variational data assimilation (3DVAR) analysis system was implemented into the operational Global Data Assimilation System (GDAS) on 1 ...

Abstract: In this study, an Observing System Simulation Experiment (OSSE) is performed to evaluate the performance of a nonlocal excess phase operator and a local refractivity operator for a GPS radio occultation (RO) sounding that ...

Abstract: n 2006, the National Centers for Environmental Prediction (NCEP) implemented the Real-Time Mesoscale Analysis (RTMA) in collaboration with the Earth System Research Laboratory and the National Environmental, Satellite, and ...