Validation of the Diurnal Cycles in Atmospheric Reanalyses Over Antarctic Sea Ice

Esa-Matti Tastula, Timo Vihma, Edgar L. Andreas, Boris Galperin

Research output: Contribution to journalArticlepeer-review

Abstract

The diurnal cycles of near-surface meteorological parameters over Antarctic sea ice in six widely used atmospheric reanalyses are validated against observations from Ice Station Weddell. The station drifted from February through May 1992 and provided the most extensive set of meteorological observations ever collected in the Antarctic sea ice zone. For the radiative and turbulent surface fluxes, both the amplitude and shape of the diurnal cycles vary considerably among different reanalyses. Near-surface temperature, specific humidity, and wind speed in the reanalyses all feature small diurnal ranges, which, in most cases, fall within the uncertainties of the observed cycle. A skill score approach revealed the superiority of the ERA-Interim reanalysis in reproducing the observed diurnal cycles. An explanation for the shortcomings in the reanalyses is their failure to capture the diurnal cycle in cloud cover fraction, which leads to errors in other quantities as well. Apart from the diurnal cycles, NCEP-CFSR gave the best error statistics.

Original languageAmerican English
JournalJournal of Geophysical Research: Atmospheres
Volume118
DOIs
StatePublished - Jan 1 2013

Keywords

  • reanalysis
  • sea ice
  • diurnal cycle
  • Antarctica

Disciplines

  • Life Sciences

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