With the incorporation of Doppler radar radial velocity by MM5/3DVAR system, a Mei-yu frontal system related to a coming heavy rain episode over southwestern Taiwan was retrieved within the Taiwan Strait on 6 June 2003. Significant frontal wind-shift (the prefrontal southwesterlies/the postfrontal northeasterlies) was reproduced over ocean, which was not captured by the NCEP reanalysis and the ...

The impact of GPS Zenith Total Delay (ZTD) measurements on mesoscale weather forecasts is studied. GPS observations from a permanent European network are assimilated into the Penn State/NCAR Mesoscale Model (MM5) using its three-dimensional variational assimilation (3DVAR) system. The case study focuses on a snow storm that occurred during the period of 14-15 December 2001 over the western Medi...

This work is the first dowel in a rather wide research activity in collaboration with Euro Mediterranean Center for Climate Changes, aimed at introducing scalable approaches in Ocean Circulation Models. We discuss designing and implementation of a parallel algorithm for solving the Variational Data Assimilation (DA) problem on Graphics Processing Units (GPUs). The algorithm is based on the full...

We develop the formalism for a PIM-based functional for stochastic tomography with a Kalman filter, in which the inversion problem associated with four-dimensional ionospheric stochastic tomography is regularized. For consistency, GPS data is used to select dynamically the best PIM parameters, in a 3DVAR fashion. We demonstrate the ingestion of GPS (IGS and GPS/MET) data into a parameterized io...

This study investigates the improvement of ozone (O3) simulations in the Mexico City basin using a threedimensional variational (3DVAR) data assimilation system in meteorological simulations during the MCMA-2003 field measurement campaign. Meteorological simulations from the NCAR/Penn State mesoscale model (MM5) are used to drive photochemical simulations with the Comprehensive Air Quality Mode...