The wave regimes of the Central Pacific Ocean with a focus on pearl farming atolls

Highlights: • Waves are one of the main drivers of atoll lagoon circulation and larval dispersal. • Three wave regimes are identified at day-scale based on height, direction and period. • Wave regimes at the atoll and rim scales are identified. • Atoll location and rim exposure strongly modify wave conditions. Pearl farming sustainability in South Central Pacific (SCP) atolls strongly depends on water quality and renewal. These factors are partly controlled by the wave conditions that impact the lagoon circulation. To characterize the wave conditions around 83 SCP atolls including those hosting pearl farming activities, we used 18 years of WaveWatchIII simulation with a grid refined from 50 to 5 km resolution. Three regional wave regimes are statistically identified: two associated with long distant swells originating from mid-latitude storms, and one with local trade winds. All regimes occur with a relatively high frequency (22–44%), but with a marked seasonality. Wave conditions are also strongly modified locally during their propagation between the archipelagoes. Western and southern isolated atolls generally have a single regime all around their rims. In contrast, central Tuamotu atolls experience different regimes depending on their levels of protection. These results help understanding atoll hydrodynamics, which has implications for their management.