A New Approach to Measuring Turbulence Properties: Responses to Shamal Events in the Northern Arabian Gulf

This study examines the impact of winter Shamal events (strong northwesterly winds that commonly generate dust storms) on water column mixing and turbulence in the northern Arabian/Persian Gulf using a newly developed method for computing turbulence properties, specifically turbulent kinetic energy dissipation rates (ε) and temperature variance dissipation rates (χ). Fast-response temperature sensors and turbulence profiling were employed during November 2023 to capture detailed time-series measurements during both Shamal and pre-Shamal periods. The results demonstrate that Shamal-induced turbulence significantly enhances air-sea exchanges of momentum and heat, driving intense wind-induced mixing and convective processes. These processes led to a sharp increase in ε and χ, particularly during the peak of the Shamal event, where ε values ranged from 10⁻⁶ to 10⁻⁴ W/kg. Based on our results from comparison of turbulence parameters during periods of different physical forcings (wind stress and convection) we suggest that moored, inexpensive, fast temperature sensors can provide reliable estimates of ε and χ time series, with margins of error less than 18% compared to a benchmark turbulence profiler. This capability is particularly significant as this study represents the first observational analysis of water column turbulence in response to Shamal events, offering valuable insights into the Gulf's broader hydrodynamic dynamics. These findings enhance our understanding of Shamal-driven mixing processes and introduce an innovative method for measuring turbulence, with broader implications for the study of ocean mixing in coastal and semi-enclosed seas as well as climate studies in air-sea interaction.