We present an efficient particle filtering algorithm for multiscale systems, which is adapted for simple atmospheric dynamics models that are inherently chaotic. Particle filters represent the posterior conditional distribution of the state variables by a collection of particles, which evolves and adapts recursively as new information becomes available. The difference between the estimated stat...

The SATREP (Satellite Report) is a detailed description of the IR and WV image in terms of conceptual models, making use of ECMWF model fields and of surface weather reports. It is meanwhile produced four times a day, at ZAMG during the day (06 and 12 UTC), at FMI in the evening (18 UTC) and at KNMI in the nightshift (00 UTC). It is desirable to have the SATREP in higher temporal frequency whic...

The performance of the ARPA-SMR Limited-area Ensemble Prediction System (LEPS), generated by nesting a limited-area model on selected members of the ECMWF targeted ensemble, is evaluated for two flood events that occurred during September 1992. The predictability of the events is studied for forecast times ranging from 2 to 4 days. The extent to which floods localised in time and space can be f...

This paper presents a quantitative methodology for evaluating air–sea fluxes related to ENSO from different atmospheric products. A statistical model of the fluxes from each atmospheric product is coupled to an ocean general circulation model (GCM). Four different products are evaluated: reanalyses from the National Centers for Environmental Prediction (NCEP) and the European Centre for Medium-...

A wavelet based methodology has been developed to retrieve the wind field over the sea surface from SAR images without any a-priori information of the wind direction. The method relies on the ability of the twodimensional continuous wavelet technique to detect the spatial structure of the Marine Atmospheric Boundary Layer (MABL). The analysis of the geometric and radiometric characteristics of ...

[1] A new type of radio occultation (RO) data, recorded in open-loop (OL) mode from the SAC-C satellite, has been tested for monitoring refractivity in the Atmospheric Boundary Layer (ABL). Previously available RO signals, recorded in phase-locked loop mode were often unusable for sensing the lower troposphere (LT) or resulted in significant inversion errors, especially in the tropics. The OL R...

The Soil Moisture and Ocean Salinity (SMOS) satellite mission of the European Space Agency (ESA), scheduled for launch in summer 2009, responds to the growing need for an accurate estimate of the root-zone soil water content. SMOS will operate at L-band frequencies, where the microwave signal is more sensitive to the soil water content. The European Centre for Medium-Range Weather Forecasts (EC...

The European Space Agency Earth Explorer mission Aeolus with the first spaceborne Doppler Wind Lidar onboard provides global coverage of wind profiles twice per day. This paper discusses impact assimilating winds on quality tropical analyses and forecasts using observing system experiments Centre for Medium-Range Weather (ECMWF). Presented examples show that bring changes to Kelvin wave structu...

Diabatic heating is diagnosed from the 40-yr ECMWF Re-Analysis (ERA-40) circulation as a residue in the thermodynamic equation. The heating distribution is compared with the heating structure diagnosed from NCEP and 15-yr ECMWF Re-Analysis (ERA-15) circulation and latent heating generated from Tropical Rainfall Measuring Mission (TRMM) observations using the convective–stratiform heating (CSH) ...