Wednesday, 17 January 2007: 11:45 AM
The response of Arctic sea ice to the North Pacific Oscillation
214C (Henry B. Gonzalez Convention Center)
The North Pacific Oscillation (NPO) and its upper tropospheric counterpart, the West Pacific (WP) pattern comprise a commonly known but infrequently documented Northern Hemisphere teleconnection pattern. The meridional dipole in sea level pressure (geopotential height) that is characteristic of the NPO (WP) results in anomalous circulation features imposed at the air-ice interface. The anomalous wind stress and temperature patterns result in both a dynamic and a thermodynamic response in the marginal ice zone (MIZ) in the Bering Sea and Sea of Okhotsk. The analysis thus far reveals the MIZ is capable of responding to changes in atmospheric circulation on the order of days and that a coherent NPO signal is observed on both monthly and weekly timescales. Furthermore, changes in the ice coverage feed back onto the atmosphere through the alteration of latent and sensible heat flux distributions. Recognition of the impact of the NPO on the MIZ leads to increased knowledge about the natural variability of one aspect of the Arctic climate, an important component of the climate system. An enhanced understanding of sea ice variability and the significance of its role in the global climate system is becoming increasingly urgent as the need to better quantify anthropogenically forced, as opposed to naturally occurring, climate change intensifies.