摘要
中国第35次南极考察队内陆考察期间在东南极中山站-Dome A断面沿线采集了4个雪坑,利用火山标志层确定了Dome A地区雪坑年层序列(1962—2018年)。雪坑离子浓度时空的分析表明,沿海地区Cl^(-)和Na^(+)浓度受海洋来源影响相对较高,Cl^(-)/Na^(+)比值从沿海到内陆逐渐增加,表明Cl^(-)除海盐源外存在其他来源或受到挥发性HCl沉积的影响。内陆地区雪坑SO_4^(2-)平均浓度较高,可能与该地区雪低积累率和中低纬度SO_4^(2-)远距离输入有关。海拔2000m以上雪坑中非海盐硫酸根(nssSO_4^(2-))占总SO_4^(2-)的比重大于90%,表明nssSO_4^(2-)的远距离输入是南极高海拔地区SO_4^(2-)离子的主要来源。积累率、下降风和沉积后作用等造成NO_(3)^(-)浓度变化复杂,显示出较大的空间异质性。离海岸距离800 km处雪坑的NO_(3)^(-)浓度较高,推测是受该地区地貌、太阳辐射冰壳和沉积后作用等因素所致。沿海地区和800km处雪坑海盐离子、NO_(3)^(-)和nssSO_4^(2-)浓度随时间变化呈现出不同的季节性特征,而离海岸距离520 km和内陆地区雪坑无明显季节变化趋势,认为是物质源区、下降风、沉积后过程和积累率等共同作用的结果。基于海冰形成的高盐度"霜花"和风吹雪,可能是沿海地区雪坑海盐离子浓度随时间增加的原因。
Following completion of the inland survey 35th Chinese National Antarctic Research Expedition,samples from four snow pits along the route from the Zhongshan Station to Dome A section in East Antarctica were analyzed using ion chromatography and major anions and cations concentrations were obtained.Stratigraphic dating(1962-2018)was attempted for a snow pit in Dome A based on seasonal variations of volcanic markers.Temporal and spatial analysis of snow pit ion concentrations show that Cl^(-) and Na^(+) concentrations in coastal areas were higher because they were affected by marine sources.A gradual increase of the Cl^(-)/Na^(+) ratio from the coast to inland areas indicates that Cl^(-) had other sources or was affected by volatile HCl deposition.The high concentrations of SO_4^(2-) inland may be associated with the low accumulation of snow or the long-distance input of SO_4^(2-) from mid-and low-latitude regions.Non-sea salt sulfate(nssSO_4^(2-))accounted for over 90% of SO_4^(2-) in snow pits above 2000 m,which indicates that long-distance input of nssSO_4^(2-) was the main source of SO_4^(2-) in high altitude areas.NO_(3)^(-) concentrations were complex and showed a large spatial heterogeneity because of accumulation rate,downwind and post-deposition effects.The high NO_(3)^(-) concentration in a snow pit 800 km away from the coast was presumed to be caused by landforms,solar radiation area and 800 km from the coast showed different seasonal characteristics,but there were no lar radiation area and 800 km from the coast showed different seasonal characteristics, but there were no obvious seasonal trends in samples from the 520 km or the inland area,which is considered the result of a combination of source,downwind,and post-deposition effects and the accumulation rate.The formation of high salinity“frost flower”and blowing salty snow on sea ice may be a plausible mechanism behind the increase of sea salt ion content in the coastal area.
作者
邓加元
李院生
马红梅
史贵涛
马天鸣
鲁思宇
Deng Jiayuan;Li Yuansheng;Ma Hongmei;Shi Guitao;Ma Tianming;Lu Siyu(College of Marine Sciences,Shanghai Ocean University,Shanghai 201306,China;Polar Research Institute of China,Shanghai 200136,China;East China Normal University,Shanghai 200241 China;School of Earth and Space science,University of Science and Technology of China,Hefei 230026,China;College of Construction Engineering,Jilin University,Changchun 130012,China)
出处
《极地研究》
CAS
CSCD
北大核心
2021年第3期374-387,共14页
Chinese Journal of Polar Research
基金
“十二五”极地专项(CHINARE201X-02-02)
国家自然科学基金(41876225)资助。
关键词
中山站–Dome
A断面
雪坑
雪冰化学
离子浓度
季节变化
Zhongshan Station-Dome A transect
snow pit
snow chemistry
ionic concentration
seasonal variations
