Early 20th century Arctic warming in retrospect

• Published in: International journal of climatology Vol. 30; no. 9; pp. 1269 - 1279
• Main Authors: Wood, Kevin R., Overland, James E.
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01.07.2010; Wiley
• Subjects: arctic warming; atmospheric circulation; climate change; Climatology. Bioclimatology. Climate change; coupled climate system; early 20th century; Earth, ocean, space; Exact sciences and technology; External geophysics; intrinsic variability; Meteorology; polar regions; North Atlantic; Atlantic Ocean; Arctic region; AN, North Atlantic; PN, Arctic; High latitude; 1920-1930; climate warming; Surface temperature; climate variability; Circulation type; Review; Meridional circulation; arctic warming; Interannual variation; Dynamical climatology; century; Atmospheric temperature; intrinsic variability; Decadal variation; Observation data; Polar region; coupled climate system; Forcing; atmospheric circulation; early 20; 1930-1940; climate change; Anthropogenic factor
• ISSN: 0899-8418; 1097-0088; 1097-0088
• DOI: 10.1002/joc.1973

The major early 20th century climatic fluctuation (∼1920–1940) has been the subject of scientific enquiry from the time it was detected in the 1920s. The papers of scientists who studied the event first‐hand have faded into obscurity but their insights are relevant today. We review this event through a rediscovery of early research and new assessments of the instrumental record. Much of the inter‐annual to decadal scale variability in surface air temperature (SAT) anomaly patterns and related ecosystem effects in the Arctic and elsewhere can be attributed to the superposition of leading modes of variability in the atmospheric circulation. Meridional circulation patterns were an important factor in the high latitudes of the North Atlantic during the early climatic fluctuation. Sea surface temperature (SST) anomalies that appeared during this period were congruent with low‐frequency variability in the climate system but were themselves most likely the result of anomalous forcing by the atmosphere. The high‐resolution data necessary to verify this hypothesis are lacking, but the consistency of multiple lines of evidence provides strong support. Our findings indicate that early climatic fluctuation is best interpreted as a large but random climate excursion imposed on top of the steadily rising global mean temperature associated with anthropogenic forcing. Copyright © 2009 Royal Meteorological Society