Fluxes and energy budget at Dome-C, Antarctica, between 1996 and 2003

The Antarctic Planetary Boundary Layer (PBL) plays a crucial role in connecting
the atmospheric, the oceanic, and cryospheric components of the Antarctic
climatic system. The knowledge of the Antarctic PBL is still poor in terms of
theoretical understanding as well as in terms of available data. The annual
radiative balance is negative and therefore the air layer close to the surface
is cooled for most of the year. In spite of low surface temperature, a regular
day time boundary layer evolution was observed, as well as a convective
activity. It became crucial to understand these processes and study processes
connected to the formation of the inversion wind, to investigate the
relationship between the surface energy balance and katabatic wind occurrence,
to assess the capability to detect the vertical motions associated with the
secondary meridional circulation, on the base of the interaction between the
large scale and the low level circulation, and with position of the polar
vortex.

Several campaigns have been carried out on the Antarctic plateau in the
station of Dome-C to achieve to answer to the cited problems as well as to test
the instrumentation to be deployed in a future long term mission. Depending on
the mission objective, several instruments could be included. Based on the
previous Antarctic experience of Sodar, but limited by the logistics two
vertical antenna Doppler minisodar (MS), to study the mixing layer height (MH)
and the associated vertical wind (W) field evolution was first deployed. A
three meter micromet mast (MM) with a sonic anemometer (SA) and a fast
hygrometer (FH) KH20 to estimate the turbulent fluxes (TF), a net radiation
station (NR) to calculate the radiation budget (RB), a ground temperature
sensors station (GT) and a flux plate (FP) to determine the energy balance (EB)
at the interface between the atmosphere and the snow covered soil were
installed. Micrometeorological tower (MT) equipped with sensors to measure the
wind speed and direction (WD) , air temperature (TA), humidity (RH), radiation
budged, soil temperature and heat fluxes were mounted. Also a microlidar (ML)
for the aerosols and ice particles (IP) profiling, and a passive microwave
radiometer (MTP-5) for the PBL temperature profiling (TP) were used.

Below, the periods, the instruments deployed and parameter measured at the
Italian-French base of Dome Concordia are listed:

DATE: 20/01/97-30/01/97:
PLATFORM: MS, MM;
INSTRUMENT: 2 ant.MS, SA, FH, NR, GT, FP;
PARAMETER (range/ height): MH (400m), WD, W, TF, RB, EB (3m).

DATE: 08/12/99-03/02/00:
PLATFORM: MS, MM;
INSTRUMENT: 2 ant. MS, SA, NR, GT, FP;
PARAMETER: MH( 400m), WD, W, TF, RB, EB (3m).

DATE: 18/11/02-17/1202:
PLATFORM: MTP-5,ML;
INSTRUMENT: MTP-5,ML;
PARAMETER: TP (600 m), IP (500 m)