Daily to intraseasonal oscillations at Antarctic research station Neumayer. Issue 2 (13th August 2013)

• Record Type: Journal Article
• Authors: Rimbu, N.; Lohmann, G.; König-Langlo, G.; Necula, C.; Ionita, M.
• Is Part Of: Antarctic science. Volume 26:Issue 2(2014)
• Page Start: 193
• Page End: 204
• Publication Date: 2013-08-13
• Subjects: climate variables, -- Madden-Julian Oscillation, -- Southern Annular Mode; Science -- Antarctica -- Periodicals; 509.989
• DOI: 10.1017/S0954102013000540
• Languages: English
• ISSNs: 0954-1020

Abstract

Abstract: High temporal resolution (three hours) records of temperature, wind speed and sea level pressure recorded at Antarctic research station Neumayer (70°S, 8°W) 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.