3.2.3 Particle confluence in the Caribbean Sea
To quantify particle density within the CS, we strategically defined ten
irregular polygons, hereafter called zones (Figure 8). We found that the
spatial distribution of particle density over one year within these
polygons is similar when using the HYCOM climatology or SOMs patterns
(Table 1; Figure 8). We also found that the areas can be grouped
according to the wind effect on particle clustering, dividing the
Caribbean into three regions:
- Region I: Comprises zone 7 (Dominican Republic-Puerto Rico Channel)
and zone 8 (Northern Lesser Antilles). This region has the most
significant particle density in the absence of wind.
- Region II: Comprises zone 1 (Yucatan Channel), zone 4
(Honduras-Jamaica Central Channel), zone 5 (Honduras-Jamaica East
Channel), and zone 6 (Jamaica-Haiti Channel). This region has the
largest confluence when including 1% windage.
- Region III: Comprises zone 2 (Quintana Roo, Mexico), zone 3
(Honduras-Jamaica West Channel), zone 9 (Southern Lesser Antilles),
and zone 10 (Central America). This region has the largest particle
confluence with a 2% windage.
Table 1 shows a breakdown of the results by zone. We identified three
main routes for particles to enter the CS: (i) along the edge of the
continental shelf by the GC, (ii) through the NBC separation and
intensification, and (iii) through the NERR and NEC dynamic interaction.
Those same inflow areas were reported by Johns et al. (2014), Goni &
Johns (2001), and Condie (1991). The resulting percentages suggest that
less than 10% of the total particles moving from the Equatorial
Atlantic to the CS reach the Caribbean coastal regions, even with 2%
windage (Table 1). The results suggest that particles enter the
Caribbean basin regardless of the windage; however, the density of
particles increases or decreases in different regions according to the
windage. We find that the effect of wind is crucial for particles to
cross transport barriers to reach the coastal zone in the western
Caribbean (zones 10, 3, and 2). Further discussion focusing on the
Mexican Caribbean (zone 2) can be found in section 3.2.3.