Boundary-Layer Meteorology

, Volume 117, Issue 1, pp 111–129

Aircraft Observations of Air-mass Modification Over the Sea of Okhotsk during Sea-ice Growth

  • Jun Inoue
  • Masayuki Kawashima
  • Yasushi Fujiyoshi
  • Masaaki Wakatsuchi
Article

DOI: 10.1007/s10546-004-3407-y

Cite this article as:
Inoue, J., Kawashima, M., Fujiyoshi, Y. et al. Boundary-Layer Meteorol (2005) 117: 111. doi:10.1007/s10546-004-3407-y

Abstract

In order to quantitatively investigate the role of leads and sea-ice in air-mass modification, aircraft observations were conducted over the partially ice-covered Sea of Okhotsk. We investigated two cold-air outbreak events with different sea-ice concentrations. In both cases, the difference between the temperatures of surface air and the sea surface (ΔT) dropped rapidly with the accumulated fetch-width of leads up to about 35-40 km, and then decreased very slowly. The surface sensible heat flux originating from open water was about 300 W m−2 within a few kilometres from the coast and decreased with increasing accumulated fetch-width. The sensible heat flux was about 100 W m−2 on average. These results indicate that the downwind air-mass modification depends mainly on the total (accumulated) extent of open water. The total buoyancy flux \(\left(\overline {w'T \, '_v}\right)\) calculated by the joint frequency distribution method correlated very well with ice concentration. Such a relationship was not clear in the case of the moisture flux \((\overline {w'q'})\). The ratio between rising thermals \(\left(\overline {w^+T^+_v}\right) \) and cold downdrafts \(\left(\overline {w^-T^-_v}\right)\) differed significantly between upwind and downwind regions; that is, the buoyancy flux was dominated by \(\overline {w^+T^+_v} \) in the developing stage of the boundary layer, while \(\overline {w^-T^-_v} \) also became important after the development of the boundary layer.

Keywords

Accumulated fetch-width of leads Leads Sea-ice Sea of Okhotsk Turbulent heat flux 

Copyright information

© Springer 2005

Authors and Affiliations

  • Jun Inoue
    • 1
  • Masayuki Kawashima
    • 2
  • Yasushi Fujiyoshi
    • 2
  • Masaaki Wakatsuchi
    • 2
    • 3
  1. 1.School of Earth and Atmospheric SciencesGeorgia Institute of TechnologyAtlantaU.S.A
  2. 2.Institute of Low Temperature ScienceHokkaido UniversitySapporoJapan
  3. 3.Core Research for Evolutional Science and Technology (CREST)Japan Science and Technology AgencyTokyoJapan

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