Trends in Atmospheric Humidity and Temperature above Dome C, Antarctica Evaluated from Observations and Reanalyses
Ricaud, Philippe ; Grigioni, Paolo ; Roehrig, Romain ; Durand, Pierre ; Veron, Dana E.
The time evolution of humidity and temperature above Dome C (Antarctica) has been investigated by considering data from (1) meteorological radiosondes (2005-2017), (2) the microwave radiometer HAMSTRAD (2012-2017), (3) four modern meteorological reanalyses (1980-2017) and (4) the southern annular mode (SAM) index (1980-2017). From these observations (2005-2017), a significant moistening trend (0.08 ± 0.06 kg m−2 dec−1) is associated with a significant warming trend (1.08 ± 0.55 K dec−1) in summer. Conversely, a significant drying trend of −0.04 ± 0.03 kg m−2 dec−1 (−0.05 ± 0.03 kg m−2 dec−1) is associated with a significant cooling trend of −2.4 ± 1.2 K dec−1 (−5.1 ± 2.0 K dec−1) in autumn (winter), with no significant trends in the spring. We demonstrate that 1) the trends identified in the radiosondes (2005-2017) are also present in the reanalyses and 2) the multidecadal variability of integrated water vapor and near-surface temperature (1980-2017) is strongly influenced by variability in the SAM index for all seasons but spring. Our study suggests that the decadal trends observed in humidity and near-surface temperature at Dome C (2005-2017) reflect the multidecadal variability of the atmosphere, and are not indicative of long-term trends that may be related to global climate change.</p>
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