Ensemble initial perturbations around Typhoon Sinlaku (2008) produced by ECMWF, NCEP, and the Japan Meteorological Agency (JMA) ensembles are compared using The Observing System Research and Predictability Experiment (THORPEX) Interactive Grand Global Ensemble (TIGGE) data, and the dynamical mechanisms of perturbation growth associated with the tropical cyclone (TC) motion are investigated for ...

The new radiation-transfer scheme RRTM is described in the article on page 2.The new scheme includes the representation of sixteen spectral bands, compared with six bands in the previous operational scheme.This allows improvements in the spectral description of the radiative properties of both the earth’s surface and the clouds.Tests of the impact of the scheme indicate improved anomaly correla...

In this study, we evaluate the ability of the BRAMS (Brazilian Regional Atmospheric Modeling System) mesoscale model compared to ECMWF global analysis to simulate the observed vertical variations of water vapour in the tropical upper troposphere and lower stratosphere (UTLS). The observations are balloon-borne measurements of water vapour mixing ratio and temperature from microSDLA (Tunable Dio...

At the European Centre for Medium-Range Weather Forecasts (ECMWF), scatterometer data from the ERS 1/2 platforms have been successfully assimilated between January 1996 up to an ERS-2 on-board failure in January 2001. This surface vector wind product over the global oceans had proven to give a positive impact on the ECMWF forecast skill in general, and the analysis of tropical cyclones in speci...

Oceanic surface pressure fields are derived from the NASA Quick Scatterometer (QuikSCAT) surface wind vector measurements using a two-layer similarity planetary boundary layer model in the midlatitudes and a mixed layer planetary boundary layer model in the tropics. These swath-based surface pressure fields are evaluated using the following three methods: 1) a comparison of bulk pressure gradie...

The climatology of atmospheric horizontal wind and its vertical gradient, i.e. wind-shear, is characterized as a function of climate region. For a better representation of the average atmospheric wind and shear and their variabilities, high-resolution radiosonde wind profiles up to about 30 km altitude are compared with collocated operational ECMWF-model ShortRange Forecast winds. Statistics of...

The work reports validation of numerical weather forecasts (NWF), QuikSCAT-based wind speed and AMSR-E sea surface temperature (SST) for the surface atmospheric boundary layer in the Indian sector of the Southern Ocean under the International Polar Year. The database consists of wind speed, air temperature, relative humidity, sea level pressure collected along the ship route from Durban (32.4°S...

The performance of single models and ensemble prediction systems has been investigated with respect to quantitative precipitation forecasts. Evaluation is based on the potential economic value of +72 h/+96 h forecasts. The verification procedure consists of taking into account all precipitation amounts that are predicted in the vicinity of an observation in order to compute spatial, multi-event...

Despite its fundamental importance in radiative transfer, atmospheric dynamics and the hydrological cycle, atmospheric water is inadequately characterized particularly at a global scale. Occultation measurements from the Global Positioning System (GPS) should imporve upon thids situation. Individual occultations yield profiles of specific humidity accurate to -0.2 gkg providing sensitive measur...