DOI: 10.5281/zenodo.7324429
title: Annual Dynamic Ice Thickness Change Rate, Greenland 1993-2017

description: This data set includes annual dynamic ice sheet thickness change rate time series reconstructed at 16,136 locations on the Greenland Ice Sheet. Time series were derived from laser altimetry data collected from 1993 to 2017 by using the Surface Elevation Reconstruction and Change (SERAC) approach (Schenk and Csatho, 2012). Ice thickness changes caused by surface processes were modeled by RACMO 2.3p2 (Noël et al., 2019) and subtracted from the total elevation change to obtain ice thickness changes due to ice dynamics. Annual rates were computed from polynomial fit (max. 3<sup>rd</sup>, order) or ALPS (Shekhar et al., 2021). <strong>Parameters:</strong> Name Description PointID Unique ID assign to location X X coordinate of time series given in meter, UTM projection (zone N24, EPSG: 32624) Y Y coordinate of time series given in meter, UTM projection (zone N24, EPSG: 32624) ObsInt Length of time series (month, from first to last observational epoch used) Hrange_flag Set according to the range of thickness change (from original time series before outlier removal). Hrange_flag=0, range of thickness change less than 5 m, annual rates computed with polynomial modeling (max 3<sup>rd</sup> order/cubic), Hrange_flag=1, range of thickness change more than 5 m, annual rates computed with ALPS. POL9394 Annual rate from polynomial interpretation for balance year 1993/94 (September 1 1993 – August 31, 1994), all years until balance year 2016/17. ALPS9394 Annual rate from ALPS modeling for balance year 1993/94 (September 1 1993 – August 31, 1994), all years until balance year 2015/16. <strong>Laser altimetry used:</strong> ATM/ATM: ATM airborne laser altimetry (Studinger et al., 2018) LVIS/LVIS: LVIS airborne laser altimetry (Blair and Hofton, 2019) ICESat/L2A-L2F: ICESat satellite laser altimetry (Zwally et al., 2014) <strong>References:</strong> Blair, J. B. and Hofton, M. (2019). IceBridge LVIS L2 Geolocated Surface Elevation Product, Version 2 [Greenland]. Boulder, Colorado USA. <em>NASA National Snow and Ice Data Center Distributed Active Archive Center. </em>https://doi.org/10.5067/E9E9QSRNLYTK. Date Accessed 11-08-2022. Noël, B. P. Y., van de Berg, W. J., Lharmitte, S., and van den Broeke, M. R. 2019. Rapid Ablation Zone Expansion Amplifies North Greenland Mass Loss, <em>Science Advances</em>, <strong>5</strong>(9), DOI: 10.1126/sciadv.aaw0123 Schenk, T. and Csatho, B. (2012). A New Methodology for Detecting Ice Sheet Surface Elevation Changes From Laser Altimetry Data. <em>IEEE Transactions on</em> <em>Geoscience and Remote Sensing, </em><strong>50,</strong> 3302–3316. Shekhar, P., Csathó, B., Schenk, T., Roberts, C. & Patra, A. K. (2021). ALPS: A Unified Framework for Modeling Time Series of Land Ice Changes. <em>IEEE Transactions on</em> <em>Geoscience and Remote Sensing,</em><strong> 59</strong>, 6466–6481. Studinger, M. (2018). IceBridge ATM L2 Icessn Elevation, Slope, and Roughness, Version 2 [Greenland]. Boulder, Colorado USA. <em>NASA National Snow and Ice Data Center Distributed Active Archive Center. </em>https://doi.org/10.5067/CPRXXK3F39RV. Date Accessed 11-08-2022. Zwally, H. J., Schutz, R., Dimarzio, J.., and Hancock. D. (2014). GLAS/ICESat L1B Global Elevation Data (HDF5), Version 34 [Greenland]. Boulder, Colorado USA. <em>NASA National Snow and Ice Data Center Distributed Active Archive Center. </em>https://doi.org/10.5067/ICESAT/GLAS/DATA109. Date Accessed 11-08-2022.