John, Prof. Willard Pierson introduced the use of statistics for reporting wave conditions back in the 1940’s. Bill has been a real contributor to oceanography for decades, with big time contributions to guiding the use of radars in space to measure ocean waves and near surface winds. He still conducts research using the latest and most advanced satellite data sets, with particular interest in the new systems that are being used to study rain storms in the tropics. Several of Pierson’s students have had highly noteworthy careers…. Your explanation of the difference between wave height and wave conditions help to explain some of Pierson’s ideas and mathematical models. Pierson is one of my heroes… he resides near New York… likes Chinese food and smokes a pipe. Bye bye bliven ========================= >From John Winters: <snipped somewhat randomly> >One should not confuse the way wave conditions are reported versus the way individual waves are measured. > The measurement of wave height is the distance from trough to crest or twice the amplitude. >The reporting of wave conditions - average wave height, significant wave heights, etc. - are based upon many waves not individual waves. >One should not assume that because wave heights are reported as being 1 meter that they will in fact be 1 meter. They will cover a range some being much higher and some much lower. ---------------------------------------------------------------------------- --- >Height is but one factor. Perhaps of greater interest to paddlers will be ratio of length to height. It is the steep breaking waves that cause capsizes not the long gentle old rollers. Generally for waves of the same height new waves are steeper than old waves and waves in shallow water are steeper than waves in deep water. ---------------------------------------------- >One can put this information to good use. You can avoid steep waves by staying offshore where waves are unaffected by shoaling water and can pay heed to changing weather conditions that will create new wind driven waves. *************************************************************************** PaddleWise Paddling Mailing List Submissions: paddlewise_at_lists.intelenet.net Subscriptions: paddlewise-request_at_lists.intelenet.net Website: http://www.gasp-seakayak.net/paddlewise/ ***************************************************************************
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