Overview

sketch of R/V Saikhon
Sketch of R/V Saikhon
  1. Test Deployments:
    • Test deployment - April, 2000
  2. Experiment Description - Tuckerton, NJ 07/00:
    • Logistics
    • R/V Saikhon Instrumentation
    • Small Buoy Instrumentation
  3. Data Analysis:
    • R/V Saikhon Measurements
    • Small Buoy Measurements
    • Waves ADCP Measurements

This program consists of a 5-year field and modeling research effort for investigating the role of bubbles injected by breaking waves and the modified in situ inherent optical properties (IOP) using measurements from a small research vessel and a moored spar buoy.

Breaking waves at the ocean's surface inject bubbles and turbulence into the water column. During periods of rough weather, the scales of wave breaking tend to increase with increasing sea states, resulting in vigorous mixing of the surface waters and the subsequent turbulent transport of bubbles to depth. The bubble clouds (or plumes) which form as a result of wave breaking, evolve as a result of turbulent water motions and also Langmuir cells (Thorpe 1982, 1984). Observations of bubbles using a variety of techniques show their presence to depths of O(10) m while the bulk of the entrained air resides in the first few meters below the surface. buoy Bubbles can significantly change the optical properties of water depending on their concentrations and size distribution, introducing potentially significant errors in retrieval of remotely-sensed hyperspectral data products.

The variability of the bubble field that results from wave breaking necessitates that the bubble and optical field be sampled with sufficient temporal and spatial resolution. Acoustic techniques have been refined over the last decade to enable us to resolve the bubble size distribution with a high degree of confidence in rough oceanic conditions and with fine temporal resolution (Terrill & Melville, 1998). Surface-layer oceanographic phenomena such as turbulent mixing and Langmuir cells will also be addressed in the investigation as they are known to play a large role in determining the depth to which bubble clouds penetrate, the bubble residence times, and the bubble size distributions. The resulting data collected will provide the necessary information for the development of physical models for the evolution of bubbles in the surface wave layer based on wind and wave forcing. Models of remote sensing reflectance will be extended from these synoptically forced bubble models to understand the role of bubbles in modifying the optical properties of the upper ocean. A byproduct of the research will be models to correct for bubble mediated effects in hyperspectral imagery such as the Coastal Ocean Imaging Spectrometer (COIS) using wind and wave information available through other remote sensors such as microwave scatterometers and synthetic aperture radar.