20 June 1975
Vol 188, Issue 4194

About The Cover

Aircraft used in atmospheric electrical research for detection of organized convection (top left). The vertical electrical field was measured between radioactive probes above and below the left wing tip. Much of the data were gathered during extended duration passes 5 meters above the ocean (bottom left). Layers of positive space charge exist at the top of the atmospheric haze layer (right) and within 150 meters of the ocean. See page 1171. [B. J. Kalpan, Newton, Massachusetts]