The Office of Naval Research announces a new Accelerated Research Initiative (ARI) on the electromagnetic properties of sea ice. The ARI is sponsored by the Ocean Optics, Remote Sensing, Arctic Sciences, Systems and Electromagnetic Theory, and Mathematics Programs. Funding in the FY1993–FY1997 time frame will support innovative research on sea ice interaction with electromagnetic radiation from the microwave through the ultraviolet.The ARI's goals are: to understand the mechanisms and processes that relate the electromagnetic properties of sea ice to its physical and morphological characteristics; to exploit this understanding to develop and verify predictive models of electromagnetic radiation interaction with sea ice; and to develop and verify mathematical inverse scattering theory using electromagnetic observables to reconstruct sea ice history geophysical properties. A balanced program of theory, laboratory, and Arctic field work is anticipated. The field work will be coordinated with the ONR Arctic Sciences Geodesic Underice Tramway System.