Estimating the Variation of Buoy Wind and Wave Data Biases

Abstract

Methods are described to find the year-to-year and station-to-station variations of lake buoy data bias. First, direct consistency testing is done among the variables: wind speed, wave height, and wave period. Second, a lake wind wave model is run from the buoy wind giving a computed wave height to compare with the measured wave height. Testing is done on Great Lakes NDBC buoy data. It is found that for any given station and year the data seem to be consistent. Wave height and period biases remain constant but the wind speed bias does vary up to about plus or minus 15%. The wind speed bias is probably affected by changes in buoy instrumentation. Such bias variations can be routinely estimated. This approach allows calibration information to be found from the actual data, replacing or improving calibrations done before or after the data period.