One Year of Surface-Based Temperature Inversions at Dome C, Antarctica

Abstract

In 2005 the Study of Stable Boundary Layer Environment at Dome C (STA-BLEDC) experimental campaign was conducted at the plateau station of Concordia at Dome C, Antarctica. Temperature profiles measured with a microwave radiometer were used to study the characteristics of surface-based temperature inversions over the course of a year. Statistics of temperature profiles for every month are discussed; the difference between daytime and nocturnal cases observed during the summer months disappears during winter. Surface-based temperature inversions occurred in 70 % of the time during summer, and almost all of the time during winter. During winter the occurrence of warming events leads to a decrease in the temperature difference between the top and the base of the inversion (i.e. the inversion strength). The inversion strength maxima ranged between 3 • C (December) and 35 • C (August) corresponding to gradients of 0.1 and 0.3 • C m −1 , respectively. The average surface-based inversion height presents a daily cycle during the summer months with values up to 200 m in the morning hours, while it affects a layer always deeper than 100 m during the winter months. The relationships between inversion strength and the downward longwave radiative flux, absolute temperature, and wind speed are examined. The inversion strength decreases as the longwave radiation increases. A clear anti-correlation between inversion strength and near-surface temperature is evident throughout the year. During the winter, the largest inversion strength values were observed under low wind-speed conditions; in contrast, a clear dependence was not found during the summer.

Stable boundary‐layer regimes at Dome C, Antarctica: observation and analysis

“…Moreover, although the sky is often clear, the temperature inversion at Dome C has been shown to decrease with the downward long‐wave radiation associated with the presence of clouds and warm moist air, particularly during sudden ‘warming events’ i.e. when air masses are advected from the coastal regions of Antarctica over the Plateau (Gallée and Gorodetskaya, 2010; Genthon et al , 2013; Barral et al , 2014b; Pietroni et al , 2014). Here, we quantify the amount of radiative energy that comes to the surface by the quantity R + , defined as where SW down and SW up are the downward and upward short‐wave radiative fluxes and LW down is the downward long‐wave radiative flux.…”

“…between 15 and 60 m (Gallée et al , 2015). On the other hand, during the polar night in winter, quasi‐permanent stable stratification occurs, with extreme temperature gradients often greater than 1 K m −1 in the first metres above the ground (Genthon et al , 2013; Pietroni et al , 2014). The turbulent boundary‐layer height does not exceed a few tens of metres or even a few metres (Pietroni et al , 2012; Casasanta et al , 2014; Petenko et al , 2014).…”

Characterization of the boundary layer at Dome C (East Antarctica) during the OPALE summer campaign

“…In addition, this allows one also to account for a possible influence of the inversion wind circulation over the Dome C area, as suggested by Pietroni et al (2014). The MAR domain is represented in Fig.…”

“…Dome C is an area where observation and modelling of the boundary layer have already been performed due to its particular location (Swain and Gallée, 2006;Sadibekova et al, 2006;King et al, 2006;Gallée and Gorodetskaya, 2010;Genthon et al, 2010Genthon et al, , 2013Brun et al, 2011;Lascaux et al, 2011;Argentini et al, 2013;Pietroni et al, 2014). Furthermore, Dome C was recently selected as the test site for the next Gewex Atmospheric Boundary Layer Studies (GABLS4) model intercomparison (see http://www.…”

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

“…Temperature, wind speed, shortwave and longwave downward radiation components can be assumed as relevant variables characterizing the state of the ABL Pietroni et al 2012Pietroni et al , 2014. The time series of these parameters for 3 February 2014 are shown in Fig.…”