Variability in accumulation rates from GPR profiling on the West Antarctic plateau
Variability in accumulation rates from GPR profiling on the West Antarctic plateau
复制标题
西南极高原探地雷达剖面积累率的变化
作者：
V. B. Spikes;G. Hamilton;S. Arcone;S. Kaspari;P. Mayewski
摘要利用探地雷达（GPR）探测的积雪等时层和冰芯分析的结果，计算了西南极沿着100 km横流剖面的积雪累积速率。积累率被证明是高度可变的短距离。全球定位系统调查的高程测量结果表明，来自浅层的积累率与表面起伏相关，这意味着风对雪的重新分布是这种变化的主要原因。将25-185年期间积累率的时间变化平滑到与地表起伏相当的沿轨迹长度尺度，以确定可能与气候变化有关的积累趋势。结果表明，积累率沿着这一剖面在最近几十年来有所下降，这是一致的核心派生的时间序列的年积累率测量的两端的雷达剖面。这些结果表明，从冰芯和GPR配置文件的积累率记录中观察到的时间变异性可以被空间的影响所掩盖，虽然它是可能的，以解决时间信号，如果当地地形和冰流的影响被量化和删除。
Abstract Isochronal layers in firn detected with ground-penetrating radar (GPR) and dated using results from ice-core analyses are used to calculate accumulation rates along a 100 km across-flow profile in West Antarctica. Accumulation rates are shown to be highly variable over short distances. Elevation measurements from global positioning system surveys show that accumulation rates derived from shallow horizons correlate well with surface undulations, which implies that wind redistribution of snow is the leading cause of this variability. Temporal changes in accumulation rate over 25–185 year intervals are smoothed to along-track length scales comparable to surface undulations in order to identify trends in accumulation that are likely related to changes in climate. Results show that accumulation rates along this profile have decreased in recent decades, which is consistent with core-derived time series of annual accumulation rates measured at the two ends of the radar profile. These results suggest that temporal variability observed in accumulation-rate records from ice cores and GPR profiles can be obscured by spatial influences, although it is possible to resolve temporal signals if the effects of local topography and ice flow are quantified and removed.