In the West Hawai‘i region (also known as the Kona Coast) eddies (gyres) form due to the funneling of the
northeast trade winds through the Alenuihāhā Channel, between Hawai‘i Island and Maui, as well as around the southern
flank of Mauna Loa at South Point. As a result, cyclonic (counterclockwise, cold core) ocean eddies are commonly
formed in the North region and anticyclonic (clockwise, warm core) eddies are commonly formed in the South region
of West Hawai‘i.
Eddies have important biological implications : Cyclonic eddies can drive upwelling of cooler, nutrient rich water
that influences ocean temperatures and fuels a localized increase in phytoplankton production, an essential source
of energy for higher trophic groups.
Eddy Kinetic Energy
(EKE) is a measure of eddy activity. Higher EKE values are an indicator of
increased eddy activity and, therefore, a potentially greater influence on marine ecosystem
We looked at EKE in the northern and southern parts of the West Hawai‘i region separately in order to
capture the strength of the cyclonic and anticyclonic eddies in the respective regions. EKE has a prominent
North-South split, with the South region characterized by more active eddy activity.
You can click and drag to zoom in on a specific portion of the graphs, double click to zoom out,
or use the slider below the graph to select a specific time period.