ASA 129th Meeting - Washington, DC - 1995 May 30 .. Jun 06

1aAO6. Are faster than predicted arrival times seeing Arctic Ocean warming?

Peter N. Mikhalevsky

Sci. Appl. Intl. Corp., McLean, VA 22102

Alexander Gavrilov

Andreev Inst. of Acoust., Moscow, Russia

Arthur B. Baggeroer

MIT, Cambridge, MA 02139

Arrival times of M sequences transmitted across the Arctic in the spring of 1994 during the trans-Arctic acoustic propagation (TAP) experiment [P. N. Mikhalevsky, 2851(A) (1994)] are faster than modeled arrival times using historical climatology. The modal dependence of the travel times appears to be consistent with a warming of the Atlantic intermediate water (AIW) in the Arctic Ocean. Calculations of the effects of this type of climate change signal, as well as ambient variability on the modal arrival times, will be presented. The possibility that the TAP results are consistent with new reports of AIW warming in the Arctic [Carmack et al., Geophys. Res. Lett. (in press) and K. Aagaard and E. C. Carmack, Science 266 (23 December 1994)] will be discussed. [Work supported by ONR, ARPA, and the Ministry of Science, Russian Federation.]