Forschungs- & Entwicklungsinformationsdienst der Gemeinschaft - CORDIS

Periodic Report Summary 1 - ASIST (Air-Sea Interaction under Stormy and Hurricane Conditions: Physical Models and Applications to Remote Sensing)

The focus of the Exchange Programme Air-Sea Interaction under Stormy and Hurricane Conditions: Physical Models and Applications to Remote Sensing (ASIST) is to develop a solid scientific basis for new microwave technologies capable of monitoring very strong (exceeding 25 m/s) winds over the sea and create new models of air-sea interaction valid for wide range of weather conditions (up to hurricanes). ASIST will lay foundations for significant advances in the meteo- and climate modelling.
The objectives of this project are threefold:
(1) to strengthen research partnerships through staff exchanges, networking and training of young scientists between 3 European research organizations from the United Kingdom, France and Germany, and 1 organization from Russia,
(2) to address the key scientific issues related to the development of novel and practical satellite based microwave technologies capable of monitoring very strong winds over the sea, and to the modelling air/sea interaction under stormy and hurricane conditions, and
(3) to develop the basis for long-term, sustainable research collaborations in this field.

The main results up to January 31, 2016 are:
1) First series (2014) experiments on AELOTRON facility in HU were performed together by the group from IAP and HU. DPIV (digital particle image velocimetry) and other optical methods have been developed and applied for simultaneous measurements of parameters of the airflow, surface roughness and underwater flows at the circular tank of the Heidelberg University (AELOTRON). Within these experiments methods of simultaneously using IR (infra-red) Imaging techniques for measurement of surface flows, LHC for surface elevation measurements and DPIV for air and water flows were developed for the first time (WP n 2, 3)
2) Pilot experiments on investigation of depolarization of X-band radar return at hurricane winds in laboratory were carried out by HU and IAP teams together in IAP at the High-speed wind-wave flume in 2014. Experiments were performed for the range up to 45 m/s equivalent 10-m wind speed. The dependence of the Normalized Radar Cross-Section on the speed for co-current and counter wind were obtained for the first time. Comprehensive study of the physical mechanisms responsible for the microwave scattering by sea surface and in the marine atmospheric boundary layer under specific conditions of strong and hurricane wind was developed with modern optical methods (WP 1, 2).
3) During the experiments HU and IAP teams developed underwater illumination system to study mechanisms of wave breaking and spray generation with shadow light visualization technique at strong wind conditions. Then series of experiments with high speed filming taking from the different sides allows to study these processes in detail (WP 1, 2)
4) Propagation of strongly nonlinear short gravity-capillary waves under the action of wind was modelled theoretically with the focus on the role of capillary ripples on the front-back asymmetry form of the gravity-capillary waves wave was studied jointly by IAP and KU during the IAP staff visit to KU (WPn1, 2)
5) Evolution of wind waves subject to strong increase of wind up to hurricane force has been modelled with the generalized kinetic equation by the KU team (WP 1, 2).
6) The nature of near-inertial motions generated by rapid changes of strong winds has been revealed by joint effort of the KU and MIO (WP 3)
7) Second series of experiments on AELOTRON facility in HU (2015) were carried out together by the group from IAP and HU. Optimal parameters for obtaining regularly braking waves of a large amplitude adjusting the parameters of the wind and depth of the water on the AELOTRON facility were estimated. New system for visualization air flow using chemically generated fog was developed. HU and IAP groups organized DPIV measurements above the breaking waves of the record amplitude within wind-wave interaction on the AELOTRON using new visualization system (WP n 2, 3).
8) The effects of foam presence on the transfer processes and the parameters of the surface roughness of the rough within the laboratory modelling of the wind-wave interaction were studied by IAP and MIO group together out on the High-speed wind-wave fume IAP, using a specially designed foam generator, and optical methods. Experiments on investigation of depolarization of radar return at hurricane winds in laboratory were carried out in IAP at the High-speed wind-wave fume of IAP for the case of the artificially made foam on the surface (WP n 1, 2).
9) MIO group developed new contact (acoustic) and optical methods for studying the turbulent processes and wavebreaking events in the air-water boundary layer (WP n 3)
10) Alexander Kandaurov successfully defended his PhD thesis in the IAP while working on the central topic of the ASIST project.

Reported by

United Kingdom


Life Sciences
Folgen Sie uns auf: RSS Facebook Twitter YouTube Verwaltet vom Amt für Veröffentlichungen der EU Nach oben