Climate and Dynamics
Effects of continental-scale snow albedo anomalies on the wintertime Arctic oscillation
Article first published online: 3 DEC 2010
Copyright 2010 by the American Geophysical Union.
Journal of Geophysical Research: Atmospheres (1984–2012)
Volume 115, Issue D23, 16 December 2010
How to Cite
2010), Effects of continental-scale snow albedo anomalies on the wintertime Arctic oscillation, J. Geophys. Res., 115, D23105, doi:10.1029/2010JD014490., and (
- Issue published online: 3 DEC 2010
- Article first published online: 3 DEC 2010
- Manuscript Accepted: 13 SEP 2010
- Manuscript Revised: 9 SEP 2010
- Manuscript Received: 12 MAY 2010
- snow cover;
- Arctic Oscillation
 The NCAR CAM3 GCM with prescribed, satellite-based snow albedo (SA) is used to investigate the remote effects of snow cover on Northern Hemisphere (NH) winter climate. A pair of 100 ensemble member experiments are integrated through the autumn-winter season, with prescribed high and low SA over Eurasia (EA). Similar to other non-CAM GCM studies using prescribed snow mass, anomalous EA snow albedo produces a wave activity pulse that propagates into the stratosphere, culminating in a negative phase Arctic Oscillation– (AO-) like surface response. This occurs for idealized but representative SA anomalies, as well as for more realistic SA anomalies. Similar experiments over North America (NA) and the entire NH are also performed. Unlike prior studies, anomalous NA snow yields a significant AO signal. Here, the local NA surface cooling elicits a transient eddy response, which propagates downstream to Eurasia, resulting in significant but short-lived cooling and upward propagating wave activity over Siberia. A negative AO-like response develops, primarily confined to the stratosphere/upper troposphere, which eventually gives way to a tropospheric AO-like response of the opposite phase, due to equatorward wave refraction and wave divergence. Reanalysis data support this NA snow-positive AO response. Snow forcing experiments for the whole NH, however, yield a weakened AO signal. This is due to a muted wavenumber-1 and -2 response caused by destructive interference between the background stationary wave and the corresponding Rossby wave response, which results in negligible wave activity reaching the stratosphere.