The variability of surface radiation fluxes over landfast sea ice near Zhongshan station, east Antarctica during austral spring

ABSTRACT

Surface radiative fluxes over landfast sea ice off Zhongshan station have been measured in austral spring for five springs between 2010 and 2015. Downward and upward solar radiation vary diurnally with maximum amplitudes of 473 and 290 W m⁻², respectively. The maximum and minimum long-wave radiation values of the mean diurnal cycle are 218 and 210 W m⁻² for downward radiation, 277 and 259 W m⁻² for upward radiation and 125 and −52 W m⁻² for net radiation. The albedo has a U-shaped mean diurnal cycle with a minimum of 0.64 at noon. Sea ice thickness is in the growth phase for most spring days, but can be disturbed by synoptic processes. The surface temperature largely determines the occurrence of ice melting. Surface downward and upward long-wave radiation show synoptic oscillations with a 5–8 day period and intraseasonal variability with a 12–45 day period. The amplitudes of the diurnal, synoptic and intraseasonal variability show some differences during the five austral springs considered here. The intraseasonal and synoptic variability of downward and upward long-wave radiation are associated with the variability of cloud cover and surface temperature induced by the atmospheric circulation.

KEYWORDS:

• Surface radiation flux
• Antarctic
• sea ice
• diurnal cycle
• synoptic and intraseasonal variability
• el niño southern oscillation (ENSO)

Acknowledgements

We thank the Chinese Arctic and Antarctic Administration and Polar Research Institute of China for the logistic support.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This study was supported by the National Natural Science Foundation of China [nos. 41376005, 41606222], the Chinese Polar Environmental Comprehensive Investigation and Assessment Program under contract [no. CHINARE2017-04-04]. The National Center for Atmospheric Research is sponsored by the U.S. National Science Foundation.