Winds and waves in the Arabian Gulf: Physics, characteristics and long-term hindcast

Abstract

A 40-year hindcast of the wave conditions in the Arabian Gulf, the elongated basin between the Arabian Peninsula and Iran, is described. The input wind fields were derived from the ERA5 reanalysis by the European Centre for Medium-Range Weather Forecasts for the period 1979-2019. Extensive comparisons with scatterometer data suggested a direction-dependent wind calibration with a strong influence on the underestimation of offshore blowing winds. The dominant wave patterns in the basin are described together with the characteristics of the related winds. After characterizing the possible meteorological conditions, the corresponding wave fields were hindcast using the WAVEWATCH III model. Extensive validation against altimeter data shows an almost unitary fit and a 0.02-m bias; a comparison with measured data strongly demonstrates that the general patterns and conditions were well reproduced. The wave physics was also analysed, revealing the crucial role of their dynamic generation in the investigated area domain. The very shallow nature of some limited coastal zones suggests that locally focused studies, with more detailed and specific physics, are required for the best description of the waves in these areas.