Northern hemisphere winter climate variability: Response to North American snow cover anomalies and orography

Publication Type  Journal Article
Year of Publication  2007
Authors  Sobolowski, S.; Gong, G.; Ting, M.
Journal Title  Geophysical Research Letters
Volume  34
Issue  16
Pages  -
Journal Date  Aug 31
ISBN Number  0094-8276
Accession Number  ISI:000249334700003
Key Words  indian-summer monsoon; maintenance; waves

[1] Links between autumn- winter snow anomalies over North America and winter climate parameters throughout the Northern Hemisphere are examined. GCM integrations are performed from September through February, with prescribed snow forcings over North America (NA) reflecting realistic, observed high/low autumn snow conditions. Forty-member ensemble differences reveal robust responses in surface air temperature and sea level pressure (SLP) fields. Over NA a negative temperature/positive SLP response occurs while over Europe a positive temperature/negative SLP response emerges. Additionally, a dynamic wave response occurs in the troposphere, across NA and extending downgradient into Eurasia. The contribution of North American (NA) orography is evaluated via an additional pair of experiments in which mountains are removed. The resulting climatic response is mitigated considerably, which suggests a nonlinear coupling of thermal and mechanical forcings. Finally, possible physical pathways for the remote response are hypothesized, involving dynamical mechanisms consistent with previous studies.


208QQTimes Cited:0Cited References Count:13

URL  <Go to ISI>://000249334700003
DOI  Doi 10.1029/2007gl030573