Hurricane Felix passed over the Bermuda testbed mooring on 15 August 1995, providing a unique opportunity to observe the response of the upper ocean to a hurricane. In the vicinity of Bermuda, Felix was a particularly large hurricane with hurricane-force winds over a diameter of about 300-400 km and tropical storm-force winds over a diameter of about 650-800 km. Felix moved northwestward at about 25 km h Ϫ1 with the eye passing about 65 km southwest of the mooring on 15 August. Peak winds reached about 135 km h Ϫ1 at the mooring. Complementary satellite sea surface temperature maps show that a swath of cooler water (by about 3.5Њ-4.0ЊC) was left in the wake of Felix with the mooring in the center of the wake. Prior to the passage of Felix, the mooring site was undergoing strong heating and stratification. However, this trend was dramatically interrupted by the passage of the hurricane. As Felix passed the mooring, large inertial currents (speeds of 100 cm s Ϫ1 at 25 m) were generated within the upper layer. The e-folding decay timescale of the inertial currents was about 9 days. The mixed layer depth was about 15 m before the arrival of Felix and deepened to about 45 m within three days after Felix's passage; the temperature at 25 m decreased by approximately 3.5Њ-4.0ЊC. Large-amplitude temperature oscillations (ϳ1.5ЊC) near the inertial period (inertial pumping effect) were set up by the hurricane in the seasonal thermocline resulting in vertical displacements of isotherms of approximately 15 m at 60-70 m. Comparative scale analyses of the upper-ocean responses to Hurricane Felix and Hurricane Gloria (1985) indicate that they have several similarities.

Biofouling is one of the primary limiting factors in terms of measurement accuracy and deployment longevity for oceanographic studies involving autonomous sampling. Copper can significantly reduce marine fouling for long-term optical sensor deployments in coastal and open-ocean environments. Copper can effectively replace previously used highly toxic chemical antifoulant methods. Copper-based antifouling systems can be employed with three types of optical sensors: 1) open, 2) enclosed or semienclosed, and 3) shuttered. Copper plates on open-faced backscattering sensors can enable deployment periods of longer than 60 days in coastal waters without biofouling. In addition, copper tubing on nine-wavelength absorption-attenuation meters (ac-9s) has extended measurement capabilities from about 10 days to greater than 60 days with no signs of biofouling in coastal waters. Implementation of copper shutters on optical sensors in open-ocean waters off Japan has resulted in extended deployment periods (410 days and possibly longer) for optical measurements whereas previous optical measurements in the open ocean were typically degraded within several weeks to at most a few months due to biofouling.

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