Data from: Temporal variability in snow accumulation and density at Summit Camp, Greenland ice sheet

• Main Author: Howat, Ian
• Format: Dataset
• Language: unknown
• Published: 2022
• Subjects: Greenland; Summit Camp; ice core; Ice Sheet
• Online Access: https://zenodo.org/record/6425866; https://doi.org/10.5061/dryad.f7m0cfxz9

A 3-year record of weekly snow water equivalent (SWE) accumulation at Summit Camp, central Greenland ice sheet, obtained by direct sampling, is presented. While the overall SWE accumulation of 24.2 cm w.e. a−1 matches long-term ice core estimates, variability increases at shorter timescales. Half of the annual SWE accumulation occurs during a few large events, with the average accumulation rate decreasing 35% between the first and second halves of the record coinciding with exceptional anticyclonic conditions in the spring and summer of 2019. No seasonality in accumulation is detected. Rather, local accumulation rates appear to be significantly impacted by wind redistribution that obscures temporal patterns in snowfall. Surface snow density is consistent, on average, with previously measured values but does not correlate with near surface temperature or wind speed. Two surface mass balance reanalysis models significantly underestimate accumulation rates at Summit Camp. This is concerning because such models are often used to estimate ice-sheet mass loss. From README_SWE_sample_logsheet.txt DATA & FILE OVERVIEW 1. Description of dataset Observations were obtained using the snow board method, where accumulation atop a board, which serves as a depth reference, is repeatedly sampled and measured. A shallow, rectangular pit is excavated, and a piece of plywood is placed over the floor of the pit. The pit is then allowed to fill with snow and settle over a period of at least two weeks. A plastic tube is used to remove a core sample of the snow from the surface to the plywood, which serves as a depth reference for each subsequent sample. The sample is taken from a different location on the board each time, as measured from flagged poles at the corner of the plywood, to provide an undisturbed sample. The snow water equivalent (SWE) of the sample is obtained from both its mass and water volume, providing redundancy for quality control. To obtain the SWE thickness of the sample from its mass, the sample is brought ...