Publication Date:
2019-12-03
Description:
High temporal resolution (three hours) records of temperature, wind speed and sea level pressure
recorded at Antarctic research station Neumayer (708S, 88W) during 1982–2011 are analysed to identify
oscillations from daily to intraseasonal timescales. The diurnal cycle dominates the three-hourly time series
of temperature during the Antarctic summer and is almost absent during winter. In contrast, the three-hourly
time series of wind speed and sea level pressure show a weak diurnal cycle. The dominant pattern of the
intraseasonal variability of these quantities, which captures the out-of-phase variation of temperature and
wind speed with sea level pressure, shows enhanced variability at timescales of , 40 days and , 80 days,
respectively. Correlation and composite analysis reveal that these oscillations may be related to tropical
intraseasonal oscillations via large-scale eastward propagating atmospheric circulation wave-trains. The
second pattern of intraseasonal variability, which captures in-phase variations of temperature, wind and sea
level pressure, shows enhanced variability at timescales of , 35, , 60 and , 120 days. These oscillations
are attributed to the Southern Annular Mode/Antarctic Oscillation (SAM/AAO) which shows enhanced
variability at these timescales. We argue that intraseasonal oscillations of tropical climate and SAM/AAO are
related to distinct patterns of climate variables measured at Neumayer.
Repository Name:
EPIC Alfred Wegener Institut
Type:
Article
,
isiRev
Format:
application/pdf
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