Sea-ice anomalies in the Sea of Okhotsk and the relationship with storm tracks in the Northern Hemisphere during winter

Authors

  • MICHEL D. S. MESQUITA,

    Corresponding author
    1. Uni Bjerknes Centre, Allegaten 55, NO-5007, Bergen, Norway
    2. Bjerknes Centre for Climate Research, Allegaten 55, NO-5007, Bergen, Norway
    3. Department of Atmospheric Sciences, University of Alaska Fairbanks, International Arctic Research Center, 930 Koyukuk Drive, Fairbanks, AK 99775, USA
      Corresponding author.
      e-mail: michel.mesquita@uni.no
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  • KEVIN I. HODGES,

    1. National Centre for Earth Observation, University of Reading, Whiteknights, PO Box 238, Reading, RG6 6AL, UK
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  • DAVID E. ATKINSON,

    1. Department of Atmospheric Sciences, University of Alaska Fairbanks, International Arctic Research Center, 930 Koyukuk Drive, Fairbanks, AK 99775, USA
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  • JÜRGEN BADER

    1. Bjerknes Centre for Climate Research, Allegaten 55, NO-5007, Bergen, Norway
    2. University of Bergen, Geophysical Institute, Allegaten 70, NO-5007, Bergen, Norway
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Corresponding author.
e-mail: michel.mesquita@uni.no

ABSTRACT

Previous studies have shown that sea-ice in the Sea of Okhotsk can be affected by local storms; in turn, the resultant sea-ice changes can affect the downstream development of storm tracks in the Pacific and possibly dampen a pre-existing North Atlantic Oscillation (NAO) signal in late winter. In this paper, a storm tracking algorithm was applied to the six hourly horizontal winds from the National Centers for Environmental Prediction (NCEP) reanalysis data from 1978(9) to 2007 and output from the atmospheric general circulation model (AGCM) ECHAM5 forced by sea-ice anomalies in the Sea of Okhotsk. The life cycle response of storms to sea-ice anomalies is investigated using various aspects of storm activity—cyclone genesis, lysis, intensity and track density. Results show that, for enhanced positive sea-ice concentrations in the Sea of Okhotsk, there is a decrease in secondary cyclogenesis, a westward shift in cyclolysis and changes in the subtropical jet are seen in the North Pacific. In the Atlantic, a pattern resembling the negative phase of the NAO is observed. This pattern is confirmed by the AGCM ECHAM5 experiments driven with above normal sea-ice anomalies in the Sea of Okhotsk.

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