Titre du document / Document title
Northern Hemisphere sea ice variability : lag structure and its implications
Auteur(s) / Author(s)
UKITA Jinro (1) ;
HONDA Meiji (2 3) ;
NAKAMURA Hisashi (2 4) ;
TACHIBANA Yoshihiro (2 5) ;
CAVALIERI Donald J. (6) ;
PARKINSON Claire L. (6) ;
KOIDE Hiroshi (7) ;
YAMAMOTO Kentaro (7) ;
Affiliation(s) du ou des auteurs / Author(s) Affiliation(s)
(1) Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY 10964, ETATS-UNIS
(2) Frontier Research Center for Global Change, Japan Agency for Marine-Earth Science and Technology Center, Yokohama, 236, JAPON
(3) International Research Institute for Climate Prediction, Palisades, NY 10964, ETATS-UNIS
(4) Department of Earth and Planetary Science, University of Tokyo, Tokyo, 113, JAPON
(5) Liberal Arts Education Center, Tokai University, Hiratsuka, 259, JAPON
(6) NASA Goddard Space Flight Center, Greenbelt, MD 20771, ETATS-UNIS
(7) Japan Meteorological Agency, Tokyo, 100, JAPON
Résumé / Abstract
An analysis of satellite sea-ice records for recent decades reveals a highly coherent spatial and temporal structure of the Northern Hemisphere (NH) wintertime sea-ice variability and its close link to anomalous atmospheric circulation. The dominant mode of the wintertime sea-ice variability is characterized by a double-dipole composed of one dipole over the North Atlantic and the other over the North Pacific, which are mutually correlated interannually. This dominant sea-ice mode is lag correlated with the winter-averaged North Atlantic Oscillation (NAO) index at lags up to two winters when the NAO leads. In the sub-Arctic, significant lead-lag relationships exist between sea-ice extent (SIE) anomalies on regional scales, which are closely associated with atmospheric circulation anomalies. An eastward evolving pattern is identified in regional SIE anomalies from the Labrador to Nordic and farther to the Okhotsk Sea at multi-year time-scales, led by anomalously weak Aleutian and strong Icelandic lows. The results suggest the presence of climate memories over the North Atlantic and Eurasia, which are crucial for recent downward trends in the NH SIE by transforming atmospheric influences into slower changes in sea-ice conditions. The summer Okhotsk high, which leads to a sea-ice reduction along the east Siberian coast and further affects sea-ice conditions over the Arctic Ocean, is a key link between summer Arctic and winter sub-Arctic sea-ice trends. We also conjecture that variations and changes in the NH sea-ice conditions are linked to climate variability in the tropics.
Revue / Journal Title
Tellus. Series A, Dynamic meteorology and oceanography
ISSN
0280-6495
CODEN TSAOD8
Source / Source
2007, vol. 59, n
o2, pp. 261-272 [12 page(s) (article)] (1 p.3/4)
Langue / Language
Anglais
Editeur / Publisher
Blackwell, Oxford, ROYAUME-UNI
(1983)
(Revue)
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Localisation / Location
INIST-CNRS, Cote INIST : 2121 A, 35400014689724.0090
Nº notice refdoc (ud4) : 18554888
