Accession Number:

ADA051530

Title:

'Shimmering', the Visual Distortion of Objects Underwater at Thermal Boundaries.

Descriptive Note:

Technical memo.,

Corporate Author:

NAVY ELECTRONICS LAB SAN DIEGO CALIF

Personal Author(s):

Report Date:

1956-09-18

Pagination or Media Count:

6.0

Abstract:

On many occasions and in different areas a phenomenon here described as shimmering has been observed during diving operations in water masses that have sharp thermal boundaries. Observations of this phenomenon have been made in the waters off southern California and Florida by the writer. Limbaugh, personal communication has observed a similar effect in the Bahamas that was so strong that underwater photographic work had to be delayed. Shimmering as defined in this memorandum is the distortion of light rays as they pass through or reflect from a turbulent thermal boundary. Visual distortion is often seen on land when hot air rises from a hot pavement surface. Shimmering has a similar visual effect in that there is also a distortion of the shape of objects viewed in the vicinity of the thermocline.

Subject Categories:

  • Anatomy and Physiology
  • Physical and Dynamic Oceanography
  • Optics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE