LONG-TERM VARIABILITY IN THE LOW-LEVEL INVERSION LAYER OVER THE
ARCTIC OCEAN

Jonathan D. W. Kahl(1), Dewayne A. Martinez(1) and Nina A. Zaitseva(2)

1 Department of Geosciences
University of Wisconsin-Milwaukee
P.O. Box 413
Milwaukee, WI 53201, USA
Internet: kahl@csd.uwm.edu

2 Central Aerological Observatory
Russian Federal Service for Hydrometeorology and Environmental Monitoring
Moscow, Russia

International Journal of Climatology

ABSTRACT

Long-term changes in the low-level tropospheric temperature inversion layer are investigated using nearly 30,000 Arctic Ocean temperature profiles during 1950-1990. The profile measurements were made by radiosonde at the former Soviet "North Pole" series of drifting ice stations, and by dropsonde from U.S. Air Force "Ptarmigan" weather reconnaissance aircraft. Significant increases in the temperature difference across the inversion layer are found during winter and autumn, indicating a strengthening of the thermal stability of the layer. This strengthening is in agreement with a recent study describing Arctic Ocean temperature trends, but is in contrast to general circulation model predictions of polar amplification of greenhouse-induced warming. The frequency with which inversion layers occur has increased, with inversions tending to be more elevated above the ice surface. Decreases in inversion layer depth reported by other investigators using similar sounding data sets are not confirmed.