Monitoring the Air/Sea Interaction and Ocean/Climate Dynamics
The white, curved area at the top of the image is a portion of the Ontong Java Atoll, part of the Solomon Islands group. The yellowish green area near the bottom of the image is an intense rain cell, which contains two dark regions, one circular and one rectangular, inside it. These dark "holes" are thought to be areas of very heavy rainfall which actually smooth out the ocean surface and result in lower radar returns.
Two smaller reddish cells are visible closer to the atoll. The red areas may be caused by reflection from ice particles in the colder, upper portion of the storm cell and not from the ocean surface at all. This provides direct evidence that it is raining within this storm cell, valuable information that is usually very difficult to measure over more remote regions of the ocean away from coastal-based weather systems. The surrounding ocean is blue to green, plus black.
Winds and currents cause the ocean surface to be rough and those variations affect how the radar signals bounce off the surface. The bright areas on the image correspond to areas where the wind speed is high. The highest winds are seen as the yellow-green region of the large rain cell. The lowest winds are seen inside the atoll as dark areas. Outside the rain cell, the winds are moderately low, indicated by the puff-like, blue patterns surrounding the cell and extending into the atoll. The long, thin, dark lines extending across the ocean are surface currents.
LightSAR's Potential Contribution:
Because LightSAR will be capable of imaging 250 to 500-km swaths, it will allow researchers to see processes on an oceanic scale. Using dual polarization modes, it will be better able to provide images that will allow determinations about the interchange of heat and moisture between the air and the upper ocean. Approximately once per week, LightSAR will image these dynamic processes as they occur in the same location.