Session: 06-16-02 Wave Mechanics, Modeling and Wave Effects II

Paper Number: 79865

79865 - The Dual Effect of Rain and Wind on Waves in a Small Lake 

Intense rain, and low wind speeds, cause wave amplitudes in the gravity-capillary range to be damped. The dual effects have been studied repeatedly in the laboratory, but, until now, therehas been almost no experiments with naturally occuring waves and weather conditions. We designed a field experiment in a small lake, both in perimeter and depth, that examines the effects of rain and wind on low amplitude waves. The experimental set-up mitigates variablerestrictions otherwise imposed by the laboratory. The rain, wind and significant wave height readings from the natural small lake mean there are no issues arising from inaccurate rain drop size spectra, lack of wind gusts or interference from wave-tank walls. Our experimental aimwas to investigate the thresholds, of both rain intensity and windspeed, that are needed to both damp and enhance the amplitude of gravity-capillary scale water waves. The research was carried out by examing wave and weather data from naturally occuring rainfall events. Agreater understanding of how the dual effects of wind and rain cause a change in wave amplitude has been reached during this experiment campaign. The results indicate further field investigations are needed to understand how the combined effects of rain and wind impact onocean waves.

Presenting Author: Claire Bergin University College Dublin

Authors:

Claire Bergin University College Dublin
Vikram Pakrashi University College Dublin
Frederic Dias University College Dublin