W.: The summer surface energy balance of the high Antarctic Plateau, Bound.-Lay

Abstract. The summertime surface energy balance (SEB) at Kohnen station, situated on the high Antarctic plateau (7500 ¢ S, 004 ¢ E, 2892 m above sea level) is presented for the period of 8 January to 9 February 2002. Shortwave and longwave radiation fluxes were measured directly; the former was corrected for problems associated with the cosine response of the instrument. Sensible and latent heat fluxes were calculated using the bulk method, and eddy-correlation measurements and the modified Bowen ratio method were used to verify these calculated fluxes. The calculated sub-surface heat flux was checked by comparing calculated to measured snow temperatures. Uncertainties in the measurements and energy-balance calcu-lations are discussed. The general meteorological conditions were not extraordinary during the period of the experiment, with a mean 2-m air temperature of)27.5 C, specific humidity of 0.52 · 10)3 kg kg)1 and wind speed of 4.1 m s)1. The experiment covered the transition period from Antarctic summer (positive net radiation) to winter (negative net radiation), and as a result the period mean net radiation, sensible heat, latent heat and sub-surface heat fluxes were small with values of)1.1, 0.0,)1.0 and 0.7 W m)2, respectively. Daily mean net radi-ation peaked on cloudy days (16 W m)2) and was negative on clear-sky days (minimum of)19 W m)2). Daily mean sensible heat flux ranged from)8 to +10 W m)2, latent heat flux from)4 to 0 W m)2 and sub-surface heat flux from)8 to +7 W m)2