Regional Spatiotemporal Statistical Database of Evaporation Ducts Over the South China Sea For Future Long-Range Radio Application

Abstract

To fully grasp the characteristics and provide a basis for establishing an evaporation duct communication system for the South China Sea (SCS), we constructed a regional statistical database based on remote sensing meteorological parameters and a numerical model. This database has the advantage of extensive spatiotemporal coverage and high resolution, which can provide accessibility and as a supplementary means for the maritime sixth Generation communication network. Specifically, work has been completed in three areas. First, the overall evaporation duct height (EDH) in the central SCS varies periodically and remains intense throughout the day, decreasing only just before sunrise during 04:00–08:00. Moreover, a 20.0 m high channel appears at the “Golden edge” in the northern coastal area, which can expand as far as 300 km from the coast during May–July. Second, the characteristics of specific regions were analyzed, and the highest average EDH was determined as 18.4 m in the Taiwan Strait. The height in the central SCS fluctuates little with monthly and annual variation, and it is maintained between 10.0 and 12.0 m. Third, based on the evaporation duct formation principle, we analyzed the spatiotemporal distributions of meteorological parameters. The Taiwan Strait maintains the highest EDH over the SCS, owing to the influence of the Kuroshio Current, and the average sea surface temperature (SST) reaches 28.41°C in June and 19.58°C in January. To the central SCS, high SST, low wind speed, and relative humidity of approximately 80% provide excellent conditions for maintaining an evaporation duct over the long term.

Keywords

• Evaporation duct
• spatiotemporal distribution
• the South China Sea (SCS)