Web Page of Dr. Stefano Zecchetto

The meso-scale meteorology studies the atmospheric phenomena of spatial scales less than 500 km and temporal scales less than 24 hours.

 

Satellite scatterometer winds provided by ERS-1, ERS-2 and NSCAT on Adeas-I, NSCAT on Adeos-II, Seawind on Quikscat, ASCAT a and b on Metop-a and b satellites are used for different purposes: to investigate the winds features in coastal regions, to verify the performances of the Numerical Weather Prediction models, and to tune the atmospheric model winds used as forcing for the storm surge models.

 

At present, the 12.5 km ASCAT a and b wind data are routinely downloaded over the European seas. The figure 1 reports the last passes of ASCAT a (left panel) and ASCAT b (right panel) over the Mediterranean Sea.

 

 

 

 

 

With the Istituzione Centro Previsioni e Segnalazioni Maree (ICPSM) of the Venice Council, the Near Real Time (NRT) scatterometer winds are used as support to storm surge prediction in Venice. Present storm surge models work on the basis of the ECMWF wind and pressure forecasts. Especially in small regional basins like the Adriatic Sea, the forecasted wind fields may result biased, and the actual bias is inferred comparing the forecasts with both the Nasa QuikSCAT and the Eumetsat ASCAT scatterometer winds, downloaded in Near Real Time from KNMI (on behalf of OSI-SAF of Eumetsat).

 

The topic of using the satellite data for improving the storm surge forecasts has been faced in the framework of the project Storm Surge for Venice (eSurge-Venice) project, funded by the European Space Agency Data User Element program.

 

 

Figure 2 reports the mean wind speed and the mean wind direction fields obtained from ASCAT a and b satellites over the Mediterranean Sea in the last 30 days. The wind direction field has been undersampled at 0.25 by 0.25 degree for readibility.

 

 

 

Selected references

Zecchetto S., A. della Valle and F. De Biasio, Mitigation of ECMWF–scatterometer wind biases in view of storm surge applications in the Adriatic Sea, Adv. Space Res., 2014, (dx.doi.org/10.1016/j.asr.2014.12.011).

De Biasio, F., M. M. Miglietta, S. Zecchetto, and A. della Valle Numerical models sea surface wind compared to scatterometer observations for a single Bora event in the Adriatic Sea, Adv. Sci. Res., 11, 41-48, 2014 (doi:10.5194/asr-11-41-2014).

Zecchetto S. and C. Accadia, Diagnostics of T1279 ECMWF analysis winds in the Mediterranean Basin by comparison with ASCAT 12.5 km winds, Quarterly Journal of the Royal Meteorological Societ, 140: 2506–2514, 2014 (doi: 10.1002/qj.2315).

Zecchetto S., F. De Biasio and C. Accadia, Scatterometer and ECMWF-derived wind vorticity over the Mediterranean Basin, Quarterly Journal of the Royal Meteorological Society, 139: 674–684, 2012 (doi: 10.1002/qj.2001).

Zecchetto S. and C. Accadia, Using ASCAT scatterometer winds to evaluate relative biases in the QuikSCAT-derived wind vorticity, IEEE Transactions on Geoscience and Remote Sensing, 50, 7, 2012 (doi: 10.1109/TGRS.2012.2184125).

Accadia, C., S. Zecchetto, A. Lavagnini and A. Speranza, Comparison of 10-m wind forecasts from a regional area model and QuikSCAT scatterometer wind observations over the Mediterranean Sea, Monthly Weather Review, 135, 1946-1960, 2007 (doi:10.1175/MWR3370.1).

Zecchetto S. and F. De Biasio, Sea surface winds over the Mediterranean Basin from satellite data (2000-2004): meso- and local-scale features on annual and seasonal timescales, Journal of Applied Meteorology and Climatology, Vol. 46, Issue 6, 814-827, 2007 (doi: 10.1175/JAM2498.1).

Zecchetto, S., F. De Biasio, S. Music, S. Nickovic and N. Pierdicca, Intercomparison of satellite observations and atmospheric model simulations of a meso-scale cyclone in the Mediterranean Sea, Can. J. Remote Sensing, Vol. 28, n. 3, 1-11, 2002.