NCEP数值预报产品浪向客观预报检验评估

Verification of Wave Direction Forecasts from NCEP Numerical Prediction Products

摘要: 利用2021年各海域船舶实况观测和业务中主用的NCEP全球海浪数值预报产品，从不同预报时效、海区、月份、起报时间和方向，开展客观、定量的海浪数值预报产品浪向要素检验评估。检验结果分析可知：在南印度洋、南太平洋和夏半年，顺时针预报偏差较多；在热带印度洋、热带太平洋和冬半年，逆时针预报偏差较多；春秋季误差相对冬夏季偏低；偏西和西南方向多为逆时针浪向预报误差，其余方向多顺时针误差；误差最高的浪向是偏北方向，最低为偏南方向；不同预报时效和起报时次的浪向预报误差相似，实际预报中可不考虑其影响。

Abstract: Using ship observations from various sea areas throughout 2021 and the NCEP global wave numerical prediction, an objective and quantitative verification of the wave direction was conducted with respect to different forecast times, areas, months, initial times, and directions. The verification reveals the following. In the South Indian Ocean, the South Pacific, and the summer half-year, clockwise forecast biases occur more frequently; in the tropical Indian Ocean, the tropical Pacific, and the winter half-year, counterclockwise biases are more common. Errors in spring and autumn are lower than in winter and summer. For westerly and southwesterly directions, the forecast errors are mostly counterclockwise, whereas for other directions, they are clockwise. The largest errors occur for northerly waves, and the smallest for southerly waves. For different forecast lead times and initial times, the wave direction errors are similar, so their influence can be disregarded in practical forecasting.