Lowest temperature and snow accumulation rate are preconditions for retrieving the oldest ice core from the polar ice sheets. The 10-m depth firn temperature at Dome A, the summit of the Antarctic Ice Sheet, recorded ...Lowest temperature and snow accumulation rate are preconditions for retrieving the oldest ice core from the polar ice sheets. The 10-m depth firn temperature at Dome A, the summit of the Antarctic Ice Sheet, recorded by an automatic weather station (AWS) was -58.3℃ in 2005 and -58.2℃ in 2006, re-spectively. The 10-m firn temperature is an approximation of the annual mean air temperature (AMAT), and this is the lowest AMAT that has been recorded on the surface of the Earth. The stable isotopic ratios (δ 18O and δ D) of surface snow at Dome A are also lower than at other ice sheet domes along the East Antarctic Ice Divide such as Dome C, Dome F, Dome B and Vostok. These facts indicate that Dome A is the "pole of cold" on the Earth. The total amount of snow accumulation rate in 2005 and 2006 was only 0.16 cm, equaling 0.016 m water equivalent per year, the lowest precipitation ever recorded from Antarctica. Preliminary evidences indicate that Dome A is a candidate site for recovering the oldest ice core.展开更多
基金the National Natural Science Foundation of China (Grant Nos. 40620120112 and 40776002)Chinese Academy of Sciences (Grant No. KZCX-SW-354)the Hundred-Talent Project of Chinese Academy of Sciences
文摘Lowest temperature and snow accumulation rate are preconditions for retrieving the oldest ice core from the polar ice sheets. The 10-m depth firn temperature at Dome A, the summit of the Antarctic Ice Sheet, recorded by an automatic weather station (AWS) was -58.3℃ in 2005 and -58.2℃ in 2006, re-spectively. The 10-m firn temperature is an approximation of the annual mean air temperature (AMAT), and this is the lowest AMAT that has been recorded on the surface of the Earth. The stable isotopic ratios (δ 18O and δ D) of surface snow at Dome A are also lower than at other ice sheet domes along the East Antarctic Ice Divide such as Dome C, Dome F, Dome B and Vostok. These facts indicate that Dome A is the "pole of cold" on the Earth. The total amount of snow accumulation rate in 2005 and 2006 was only 0.16 cm, equaling 0.016 m water equivalent per year, the lowest precipitation ever recorded from Antarctica. Preliminary evidences indicate that Dome A is a candidate site for recovering the oldest ice core.
