A portable lightweight in situ analysis (LISA) box for ice and snow analysis

Helle Astrid Kjær,Marius Simonsen,Lisa Lolk Hauge,Zurine Yoldi,Johannes Freitag,Sepp Kipfstuhl,Paul Vallelonga,Maria Hörhold,Iben Koldtoft,Anders Svensson

doi:10.5194/tc-15-3719-2021

Abstract

Abstract. There are enormous costs involved in transporting snow and ice samples to home laboratories for “simple” analyses in order to constrain annual layer thicknesses and identify accumulation rates of specific sites. It is well known that depositional noise, incurred from factors such as wind drifts, seasonally biased deposition and melt layers can influence individual snow and firn records and that multiple cores are required to produce statistically robust time series. Thus, at many sites, core samples are measured in the field for densification, but the annual accumulation and the content of chemical impurities are often represented by just one core to reduce transport costs. We have developed a portable “lightweight in situ analysis” (LISA) box for ice, firn and snow analysis that is capable of constraining annual layers through the continuous flow analysis of meltwater conductivity and hydrogen peroxide under field conditions. The box can run using a small gasoline generator and weighs less than 50 kg. The LISA box was tested under field conditions at the East Greenland Ice-core Project (EastGRIP) deep ice core drilling site in northern Greenland. Analysis of the top 2 m of snow from seven sites in northern Greenland allowed the reconstruction of regional snow accumulation patterns for the 2015–2018 period (summer to summer).

Highlights

To evaluate future sea level changes, surface mass balance (SMB) determinations of the major ice sheets and ice caps are an important constraint
Ice cores are spatially limited for practical reasons: drilling campaigns of deep ice cores are expensive, as they require the maintenance of large-scale facilities for several years; drilling campaigns of shorter snow and firn cores are cheaper, they are still costly in terms of time and money
It is worth noting that the resemblance between the measurements at the B19 and S5 sites, where the snow cores were retrieved just few centimetres apart, demonstrates the repeatability of the lightweight in situ analysis” (LISA) box

Summary

Introduction

To evaluate future sea level changes, surface mass balance (SMB) determinations of the major ice sheets and ice caps are an important constraint. Ice cores are spatially limited for practical reasons: drilling campaigns of deep ice cores are expensive, as they require the maintenance of large-scale facilities for several years; drilling campaigns of shorter snow and firn cores are cheaper, they are still costly in terms of time and money. Using one or more profiles of an ice core site, an accurate timescale can be established by dating and, if the density is measured, the local accumulation rate of a site can be reconstructed (Winstrup et al, 2019; Philippe et al, 2016)

Methods

Results

Conclusion