Coral spawn and bathymetric slicks in Synthetic Aperture Radar (SAR) data from the Timor Sea, north‐west Australia

Evolution of ocean slicks under a rising wind

“…This pattern clearly differs from that of Figure 1b, which applies strictly to the dispersion of passive surface particles. These characteristics resemble those reported for oil spills, and a possibly related asymmetry was described by Kraus [1967] in experiments using artificially produced slick patches and also recently by Jones et al [2006]. In the case of an oil spill, windrows are typically observed along only the upwind end of the spill, where the oil layer is relatively thin; but oil accumulates at the downwind end, where viscous effects dominate the dynamics [Lehr and Simecek-Beatty, 2000].…”

“…Naturally occurring organic surface films, or slicks, are of wide interest because of their influence on air‐sea interaction and remote sensing. Examples include: contamination of satellite‐based retrievals of sea‐surface temperature and wind [ Robinson and Donlon , 2003; Hashizume and Liu , 2004]; analysis of altimeter data [ Tournadre et al , 2006]; modification of air‐sea gas transfer [ Zappa et al , 2004; Schimpf et al , 2006]; visualization of hydrodynamic features such as internal waves and eddies [e.g., Johannessen et al , 2005; da Silva et al , 1998; DiGiacomo and Holt , 2001]; estimation of surface currents [e.g., Lyzenga and Marmorino , 1998; Matthews , 2005]; and indication of algal blooms [e.g., Jones et al , 2006]. Also, natural slicks can be confused with oil (mineral or petroleum) spills in the interpretation of imagery for pollution assessment [e.g., Alpers and Espedal , 2004].…”

Australian offshore natural hydrocarbon seepage studies, a review and re-evaluation

“…Assessments of natural hydrocarbon seepage that have included interpreted SAR slicks have been documented for the Timor Sea (O'Brien et al, , 2003a(O'Brien et al, , 2003bJones et al, 2005bJones et al, , 2006Rollet et al, 2006), the central North West Shelf (O'Brien et al, 1998b(O'Brien et al, , 2003cJones et al, 2007), the Great Australian Bight (Struckmeyer et al, 2002) and the Arafura Sea .…”

Assessing the effect of hydrocarbon oil type and thickness on a remote sensing signal: A sensitivity study based on the optical properties of two different oil types and the HYMAP and Quickbird sensors

“…SAR has the advantage of covering large geographic areas but SAR data contains no diagnostic spectral information. This means that other phenomena that cause dampening of capillary waves, such as natural film, bathymetric features, weather and even coral spawn (Jones et al, 2005(Jones et al, , 2006Thankappan et al, 2007) can lead to a range of false positive interpretations of natural oil slicks. Compared to SAR, optical remote sensing offers further possibilities for identifying and characterising naturally occurring petroleum hydrocarbon slicks, with potential applications ranging from locally targeted airborne hyperspectral acquisitions to multispectral spaceborne sensors with global coverage.…”