Improvements of storm surge forecasting in the Gulf of Venice exploiting the potential of satellite data: the ESA DUE eSurge-Venice project

ABSTRACT

The northern Adriatic Sea is affected by storm surges, which often cause the flooding in Venice and the surrounding areas. We present the results of the eSurge-Venice project, funded by the European Space Agency (ESA) in the framework of its Data User Element programme: the project was aimed to demonstrate the potential of satellite data in improving storm surge forecasting, with focus on the Gulf of Venice. The satellite data used were scatterometer wind and altimeter sea level height. Hindcast experiments were conducted to assess the sensitivity of a storm surge model to a model wind forcing modified with scatterometer data and to altimeter retrievals assimilated with a dual 4D-Var system. The modified model wind forcing alone was responsible for a reduction of the mean difference between modelled and observed maximum surge peaks from −15.1 to −8.2 cm, while combining together scatterometer and altimeter data the mean difference further reduced to −6.0 cm. In terms of percent, the improvements in the reduction on the mean differences between modelled and observed surge peaks reaches 46% using only the scatterometer data, and 60% using both scatterometer and altimeter data.

KEYWORDS:

• Storm surge
• scatterometry
• ocean winds
• altimetry
• data assimilation
• Adriatic Sea
• Venice

Acknowledgements

This work has been carried out on the framework of the project Storm Surge for Venice (eSurge-Venice, www.esurge-venice.eu) funded by the European Space Agency as part of its Data User Element (DUE) programme. The QuikSCAT and Oceansat-2 winds have been processed by the Jet Propulsion Laboatory/California Institute of Technology; the ASCAT winds by the EUMETSAT Ocean and Sea Ice Satellite Application Facility (OSI-SAF); the satellite Sea Surface Temperatures by the Operational Sea Surface Temperature and Sea Ice Analysis (OSTIA) system. The satellite winds and the OSTIA SST have been downloaded from the NASA Physical Oceanography Distributed Active Archive Center (PO.DAAC) at the Jet Propulsion Laboratory/California Institute of Technology. Altimetry data were provided by the CTOH/LEGOS, France, while in-situ data have been obtained from the Venice Tide Centre of the Venice Municipality. The ECMWF fields have been obtained thanks to the authorization from the Aereonautica Militare Italiana. This work has also been supported by the Flagship Project RITMARE funded by the Ministero dell'Istruzione, dell'Università e della Ricerca of Italy.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work has been carried out on the framework of the project Storm Surge for Venice (eSurge-Venice, www.esurge-venice.eu) funded by the European Space Agency as part of its Data User Element (DUE) programme. This work has also been supported by the Flagship Project RITMARE funded by the Italian Ministry of University and Research.