Local-scale spatial variability in firn properties in Southwest Greenland

• DOI: 10.3389/feart.2022.938246
• Publication Date: 2022-10-21T05:41:35Z
• Authors: Jing Xiao; Åsa K. Rennermalm; Federico Covi; Regine Hock; Sasha Z. Leidman; Clément Miège; Michael J. MacFerrin; Samira Samimi
• Keywords: Firn; Ice core; Meltwater; Greenland ice sheet; Groenlandia

The increasing mass loss from the Greenland ice sheet is becoming growingly important to present-day global sea level rise. Meltwater export ocean may be amplified by near-surface layers in firn (i.e., snow that has survived at least one melt season) which prevent infiltration. Such have been documented various sites southwest Greenland, but little known about local-scale (less than 1 km) variability and properties. Here we investigate local density content (ice layer thickness fraction) analyzing 45 shallow cores retrieved 15 between 2012 2019. core dataset contains groups of were collected same site (1–632 m apart each other) year (here referred as site/year cores). two-sided Mann-Whitney U -tests suggest most do not statistically significant differences median or over upper 0–4.5, 4.5–9, 9–13.5 sections below winter layer. That said, still exhibit substantial well variable stratigraphy (especially distribution centimeters-thick lenses) explainable measurement uncertainties. (calculated cores) three 4.5-m 4% 19–29%, respectively. comparable regional gradient our study area within an elevation difference up ∼200 m. non-negligible particularly mid- high-elevation (>2,000 a.s.l.), where structure changes such formation are more recent phenomena compared lower elevations. This confirms single can provide representative bulk statistics mean site. However, these values mask compromise comparisons. Therefore, collection consideration necessary for in-depth analysis variability.