DOI: 10.5061/dryad.zpc866tb8
title: Accelerating ice loss from peripheral glaciers in North Greenland

description: In recent decades, Greenland’s peripheral glaciers have experienced
 large-scale mass loss, resulting in a substantial contribution to
 sea-level rise. Only 4% of Greenland’s ice cover are small peripheral
 glaciers that are distinct from the ice sheet proper. Despite comprising
 this relatively small area, these small peripheral glaciers are
 responsible for 11% of the ice loss associated with Greenland’s recent
 sea-level rise contribution. Using the satellite laser platforms ICESat
 and ICESat-2, we estimate that ice loss from these Greenland glaciers
 increased from 27±6 Gt/yr (2003–2009) to 42±6 Gt/yr (2018–2021). Here, we
 provide the laser altimetry assessment of changing ice loss rates from
 Greenland peripheral glaciers that bridges both the ICESat and ICESat-2
 periods of Feb 2003 – Dec 2021. We provide peripheral glaciers elevation
 changes including correction for firn compaction, elastic uplift rates
 from present-day mass changes, and long-term past ice changes (Glacial
 Isostatic Adjustment- GIA). We provide: (1) Mean elevation change rates of
 the Greenland peripheral glaciers during, Feb 2003 - Oct 2009, Oct 2008 -
 Apr 2019, and Oct 2018 – Dec 2021 obtained from ICESat and ICESat-2 data.
 The grid resolution is 500x500 meters. (2) Mean elastic uplift rates of
 the bedrock (in mm/yr) due to ice loss during, Feb 2003 - Oct 2009, Oct
 2008 - Apr 2019, and Oct 2018 – Dec 2021. (3) Mean firn compaction rates
 in m/yr during, Feb 2003 - Oct 2009, Oct 2008 - Apr 2019, and Oct 2018 –
 Dec 2021. (4) Glacial Isostatic Adjustment- GIA rates in mm/yr from the
 GNET-GIA empirical model of Khan et al. (2016). (5) Time series of mean
 surface air temperature in degrees Celcius during May-September in north,
 northwest, southeast, southwest, and northwest Greenland from RACMO2.3p2.
    
description: We use ICESat data from
 February 2003 to October 2009 to estimate elevation changes over the ice
 surface. We estimate height changes over the ice surface, on a regular
 grid with a resolution of 500x500 m that covers all of Greenland’s
 peripheral glaciers. We use all available ICESat data to create height
 time series at each grid point. At each grid point, we fit a trend, a
 second-order surface topography, and a seasonal term to account for the
 annual surface changes. The observed height change rates from ICESat are
 interpolated into a regular grid of 500x500 m. The interpolation is
 performed using the ordinary kriging method. We used the observed
 elevation change rates to estimate an empirical semi-variogram. Next, we
 fit an exponential model variogram (with a range of 60 km) to the
 empirical semi-variogram to take the spatial correlation of elevation
 change rates into account in the error budget. For each grid point, we
 estimate elevation change rate dh and associated error.
 We
 correct the observed height change rates for firn compaction, elastic
 uplift rates from present-day mass changes, and long-term past ice changes
 (Glacial Isostatic Adjustment- GIA). We correct for GIA, using the
 GNET-GIA empirical model of Khan et al. (2016). For each grid point, we
 estimate the GIA uplift rate and the associated uncertainty. To correct
 for elastic uplift of the bedrock, we convolve ice loss estimates of
 peripheral glaciers and the Greenland ice sheet with the Green’s functions
 derived by Wang et al. (2012) for elastic Earth model iasp91 with refined
 crustal structure from Crust 2.0.
description: File List:
 GRL_Khan_2022GL098915.zip
 This compressed file contains
 five directories: Directory 1 "dhdt": Description: Mean
 elevation change rates of the Greenland peripheral glaciers during, Feb
 2003 - Oct 2009, Oct 2008 - Apr 2019, and Oct 2018 – Dec
 2021 Directory 2 "elastic" Description:
 Mean elastic uplift rates of the bedrock (in mm/yr) due to ice loss
 during, Feb 2003 - Oct 2009, Oct 2008 - Apr 2019, and Oct 2018 – Dec
 2021. Directory 3 "firn" Description: Mean
 firn compaction rates in m/yr during, Feb 2003 - Oct 2009, Oct 2008 - Apr
 2019, and Oct 2018 – Dec 2021. Directory 4 "GIA" Description: Glacial
 Isostatic Adjustment- GIA rates in mm/yr from the GNET-GIA empirical model
 of Khan et al. (2016). Directory 5 "temp" Description: Time
 series of mean surface air temperature in degrees Celcius during
 May-September in north, northwest, southeast, southwest, and northwest
 Greenland from RACMO2.3p2.