Spectral characteristics of East Antarctica meteorological parameters during 1994

Abstract

Abstract. A data set recorded during 1994 from the Dome Charlie and D-80 automatic weather stations and the Dumont d'Urville meteorological station has been used to investigate the time variation and the spatial distribution of pressure, temperature, and wind velocity over East Antarctica. The advanced procedures of wavelet analysis, highresolution spectral estimation, and their combination were used for this study. Special attention was devoted to the temperature behavior during winter. The surface temperature inside the continent shows strong oscillations with a period of -10 days and a sharp increase ranging from 20øC to 40øC during the winter season. Cross-covariance functions between temperature and pressure at different sites were analyzed to estimate the correlation between warming events and their temporal and spatial distribution. The warming is more often associated with high-pressure anomalies and follows the variation of the pressure with a delay varying from some hours to 1 day. Sharp changes in wind speed and direction generally occur when the temperature increases. In such cases the wind has the tendency to blow from the W-NW sector, deflecting from the dominant katabatic flow direction. IntroductionThe

Transitions in the wintertime near‐surface temperature inversion at Dome C, Antarctica

“…However, strong low-pressure systems over the austral ocean occasionally bring relatively warm and moist maritime air towards the East Antarctic Plateau. These so-called "warming events" may give rise to a sudden temperature increase of tens of degrees over several hours (Argentini et al, 2001;Gallée and Gorodetskaya, 2010). They modify the surface radiation budget (Ricaud et al, 2017) and are likely responsible for most of the snowfall at Dome C (Genthon et al, 2016).…”

Sampling the ground layer of the atmosphere at Dome C using fast sonic-anemometers

“…The july temperatures are warmer than they are at the beginning and the end of the winter period. This effect documented by Neff [3] and Argentini [4] is due to synoptic perturbations which correlate with increase in pressure and a change in wind direction. During this period, however, we did not notice a change in the vertical profile of temperature, nor did the inversion show unusual behavior.…”

Wavelike Structures in the Turbulent Layer During the Morning Development of Convection at Dome C, Antarctica

“…Episodic synoptic perturbations, due to maritime air intrusions produce wind speeds of up to 10 m s −1 , significantly higher temperatures (up to −20 • C) and dense cloudiness (e.g. Argentini et al 2001;Genthon et al 2013). …”