Airborne Laser Altimeter, Global Positioning System (GPS), Inertial Measurement Unit (IMU) and Imagery Campaign of the Surging Negribreen Glacier, Svalbard, in August 2019

### Access

Dataset can be accessed and downloaded from the 'ADC' directory via: [http://arcticdata.io/data/10.18739/A2X63B701](https://arcticdata.io/data/10.18739/A2251FN18/)

### Overview

The Negribreen Glacier System (NGS), one of largest glacier systems in Svalbard, began surging in 2016 and continues to move at relatively fast speeds through 2021. Negribreen has not surged since 1935-1936 and hence there is no modern study on its surge dynamics. A surge-type glacier cycles quasi-periodically between a long quiescent phase of normal flow and a short surge phase when ice speeds increase by a factor of 10-200 times that of quiescence. The rapid ice-acceleration leads to a vicious cycle of wide spread crevassing, rapid advance, and increased calving that lead to catastrophic ice loss and frontal retreat. During the peak surge period in 2017, the ice loss from Negribreen is estimated to have contributed 5-1.0% of total annual global sea-level rise. The fast moving ice of surging Negribreen stood in stark contrast to the slow-moving, smooth ice of its largest side glacier, Ordonnansbreen - until in May 2019, when a sudden acceleration was observed in Ordonnansbreen in satellite data of the European Space Agency's Sentinel-1, which motivated the 2019 field campaign.

During our project (Ordonnansbreen NSF RAPID), we collected laser altimeter, Global Positioning System (GPS), Inertial Measurement Unit (IMU), image and video data from small helicopter, to obtain high-resolution elevation data suitable for process studies and to complement satellite data. This data package includes the field data from one of our campaigns in August 2019 (negri\_2019). Within this directory are folders containing each our data sets for the campaign: (1) The 400 hertz (Hz) raw 905 nanometer (nm) laser altimeter data from LaserTech's Universal laser System (ULS) along with an error logfile (laser), (2) Handheld image data from a Nikon D5100 (D5100), and two Nikon Coolpix cameras (L120-1 and L120-2), (3) 1-Hz GPS data from a simple USB-connected GPS receiver (button\_GPS), (4) 10-Hz raw and processed GPS data from a base (Trimble NetR9) and rover (Trimble R10) kinematic GPS system borrowed from UNAVCO (gps\_unavco), (5) 1-Hz IMU data from a LORD 3DM-GX5-15 Virtual Reference Unit (imu), and (6) 2-Hz imagery from a GoPro Hero-5 mounted on the underside of the helicopter (gopro). A README file is included at the top of the directory structure that specifies the data format for each data type.

The main goal of the 2019 Ordonannsbreen NSF RAPID was to collect data to study a new acceleration in Ordonnansbreen, the second largest glacier in the NGS, during surge of the NGS, aimed at studying the effects of the surge in the Negribreen on neighboring glacier and ice regions. The campaign was synergistic with a NASA Earth Sciences project of the PI, aimed at validation of ICESat-2 data and evaluation of a data analysis algorithm, the DDA-ice (for more information, see the Herzfeld et al. 2023 paper with DOI: 10.3390/rs14051185). Airborne flight survey lines were optimized to meet objectives of both projects. Flight data collected in support of both projects are included in this data set. The 2019 campaign consisted of two successful flights and each of the data subfolders above contain additional subfolders labeled Flight1 or Flight2. A data set may be missing data for a given flight due to instrument failure. We were not able to reach lower Negribreen during Flight 2 of 2019 due to low lying clouds, so instead we collected data from upper Negribreen only. Some flights include photographic documentation of Tunabreen and other glaciers along the transit flight to Negribreen.