9811976 Herbert This SGER will support a pilot project to develop the use of combined alkenone unsaturation ratios (Uk1 37) and 6 18 O in a surface-dwelling planktic foraminifer to resolve sea-surface temperature from ice-volume of ocean water (which varies inversely with ice volume on land) and is widely used as a tracer of past changes in ocean circulation and global climate. In order to assign quantitive values to the two controls, a second variable is needed . Alkenone unsaturation is believed to be controlled purely by ambient temperature, with no ice-volume effect, so that combining Uk 37 and 618 O should permit the PI to solve two simultaneous equations to derive quantitative estimates of both ocean temperature and global ice volume for past climate states. These climate models to understand long-term climate variability.
