气候变化领域集成服务门户(CCPortal): Stable water isotopes measured along two snow trenches sampled at Kohnen Station, Dronning Maud Land, Antarctica in the 2014/15 field season

CCPortal

DOI	https://doi.org/10.1594/PANGAEA.876639
	Stable water isotopes measured along two snow trenches sampled at Kohnen Station, Dronning Maud Land, Antarctica in the 2014/15 field season
	Münch; Thomas; Kipfstuhl; Sepp; Freitag; Johannes; Meyer; Hanno; Laepple; Thomas
发布日期	2017-06-24
数据集类型	dataset
英文简介	The isotopic composition of water in ice sheets is extensively used to infer past climate changes. In low-accumulation regions their interpretation is however challenged by poorly constrained effects that may influence the initial isotope signal during and after deposition of the snow. This is reflected in snow-pit isotope data from Kohnen Station, Antarctica, which exhibit a seasonal cycle but also strong inter-annual variations that contradict local temperature observations. These inconsistencies persist even after averaging many profiles and are thus not explained by local stratigraphic noise. Previous studies have suggested that post-depositional processes may significantly influence the isotopic composition of East Antarctic firn. Here, we investigate the importance of post-depositional processes within the open-porous firn (> 10 cm depth) at Kohnen Station by separating spatial from temporal variability. To this end, we analyse 22 isotope profiles obtained from two snow trenches and examine the temporal isotope modifications by comparing the new with published trench data extracted 2 years earlier. The initial isotope profiles undergo changes over time due to downward-advection, firn diffusion and densification in magnitudes consistent with independent estimates. Beyond that, we find further modifications of the original isotope record to be unlikely, or small in magnitude (<< 1 per mil RMSD). These results show that the discrepancy between local temperatures and isotopes most likely originates from spatially coherent processes prior to or during deposition, such as precipitation intermittency or systematic isotope modifications acting on drifting or loose surface snow.
空间范围	Median Latitude: -75.008522 * Median Longitude: 0.088500 * South-bound Latitude: -75.009860 * West-bound Longitude: 0.079600 * North-bound Latitude: -75.007190 * East-bound Longitude: 0.097200
时间范围	2015-01-24T00:00:00 - 2015-01-28T00:00:00
语种	英语
国家	国际
学科大类	气候变化
学科子类	气候变化
文献类型	数据集
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/215319
推荐引用方式 GB/T 7714	Münch,Thomas,Kipfstuhl,et al. Stable water isotopes measured along two snow trenches sampled at Kohnen Station, Dronning Maud Land, Antarctica in the 2014/15 field season.2017-06-24.https://doi.org/10.1594/PANGAEA.876639.