Seasonal and interannual variability of temperature inversions in the subarctic North Pacific

Hiromichi Ueno, Eitarou Oka, Toshio Suga and Hiroji Onishi
Argo Group
Institute of Observational Research for Global Change,
Japan Agency for Marine-Earth Science and Technology
2-15 Natsushima-cho, Yokosuka, Kanagawa,
237-0061, JAPAN

Hydrographic data from profiling floats obtained during 2000-2004 were analyzed
to study seasonal and interannual variability of temperature inversions (T-invs)
in the subarctic North Pacific (SNP).
In the western SNP and Bering Sea, the temperature minimum at the top of T-invs
outcropped and was renewed every winter, causing a seasonal cycle in the magnitude
of T-invs, with the maximum at the end of winter.
In the Gulf of Alaska in the eastern SNP, the temperature minimum outcropped in winters
2002 and 2004, but scarcely outcropped in winter 2003.
Consequently, the magnitude of the T-invs showed remarkable interannual variation;
its monotonic decrease through winter 2003 overwhelmed the seasonal cycle.
The year-to-year variation of the magnitude of the T-invs in each region of the SNP was
consistent with and thereby attributable to that of the winter sea surface temperature anomaly there.