Publication Date:
2014-09-10
Description:
ABSTRACT Hourly time-series of several atmospheric state variables and downwelling longwave radiation (LW d ) collected through the extended winter (mid-December 2007 to March 2008) of the International Polar Year-Circumpolar Flaw Lead (IPY-CFL) ship-board campaign in Amundsen Gulf were analysed. A histogram derived from the hourly LW d time-series revealed a positively (right) skewed frequency distribution. The cold, dry, and mainly clear weather or mean atmospheric states concurrent with the modal and adjacent classes showed that LW d observations within ±30 W m −2 of the modal class mark (160 W m −2 ) identify the presence of the semi-permanent cold-core high pressure centre which appears on average winter mean sea-level pressure maps for the western maritime Arctic. The warmer, moister, and cloudier weather or mean atmospheric states associated with LW d bins in the right tail of the positively skewed frequency distribution, and the weather coincident with the deepest mean sea-level pressure minima, showed that observations of LW d in the 210–280 W m −2 range identified the passage of baroclinic disturbances. While a right skewed LW d frequency distribution usually occurs, the class mark of the major modal class, and the class marks of the bins in the right tail of the distribution show inter-annual variability of ±10 to 30 W m −2 . Owing to its inclusive nature, validation of modelled LW d may provide a comprehensive verification statistic for Arctic climate simulations.
Print ISSN:
0899-8418
Electronic ISSN:
1097-0088
Topics:
Geosciences
,
Physics
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