IASC Workshop on the dynamics andmass budget of Arctic glaciers

Abstracts and program
Network on Arctic Glaciology annual meeting &IASC cross-cutting activity on “Glacier-atmosphere interactions in a warming and wetting Arctic”
26-28 January 2023, Obergurgl, Austria
Organised by: Ward van Pelt, Jakob Abermann and Wesley Van
WychenNetwork on Arctic Glaciology

ISBN: 978-91-527-7764-0

Participants of the 2023 IASC workshop on Arctic Glaciology in Obergurgl, Austria.
(Photo: Erika Brummell)Contents
Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3

Schedule . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4

Posters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

8Participants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

9Minutes of the IASC-NAG open forum meeting . . . . . . . . . . . . . . . .

11

Abstracts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

13

Calving response to the propagation of a speedup pulse through the ice
stream of Sermeq Kujalleq in Kangia (Jakoshavn Isbræ), Greenland . . . . .

13

Ice stream flow dynamics of Sermeq Kujalleq observed with detailed repeated UAV surveys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

13

The Greenland Climate Network v.2 - a new era of monitoring the Greenland ice sheet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

14

Multidecadal reconstruction of the surface mass balance of an Arctic glacierusing reanalysis data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Dynamics throughout a complete surge of Iceberg Glacier on western Axel
Heiberg Island, Canadian High Arctic . . . . . . . . . . . . . . . . . . . . . . . . .

15

15 years Mass Balance Measurements at Freya Glacier, NE-Greenland . . .

16

Crustal Uplift: a regional response to contemporary ice mass loss . . . . .

16

Resilience of the Greenland ice sheet firn layer under future climate warming 16
Little Kluane Glacier, Yukon: a tributary-trunk surge. . . . . . . . . . . . . .

17

Recent patterns of velocity and elevation change, and their associateddrivers, Hubbard Glacier, Alaska . . . . . . . . . . . . . . . . . . . . . . . . . . .

18

Evolving Ice Fraction in the Shallow Firn Layer of Devon Ice Cap, Nunavut
between 2011 to 2022 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

18

Changes in the extent and velocity of the Hornbreen - Hambergbreen system (S Spitsbergen) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

19

Geodetic mass balance of a small glacier in the Canadian High Arctic determined from historical aerial photography . . . . . . . . . . . . . . . . . . . .

20

Assessing the 2021-2022 surge behaviour of Lowell Glacier . . . . . . . . .

20

Hydrothermal structure of Elfenbeinbreen and Sveigbreen, Sabine Land,
Svalbard, and its changes for Sveigbreen during 2014-2022 . . . . . . . . .

21

Reconstructing the past two surges of Fisher Glacier, Yukon . . . . . . . . . .

22North Atlantic cooling and the impact on Icelandic glacier mass balance .

22

Greenland slush limits; comparing remote sensing and RCM simulations .

22

Reconnaissance of Alfred Wegener’s West Greenland Expedition: bridging
a century of climate change work: 1929 to 2022 . . . . . . . . . . . . . . . . .

23

Vertical ice - morphology of the terrestrial ice margin in Greenland . . . . .

24

1

Trends in Greenland ice sheet observational records: implications for changing ice volume . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Glacier recession vs. water drainage at a forefield (Werenskioldbreen,
Svalbard) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

24

Present changes of Jostedalsbreen, Norway’s largest ice cap . . . . . . . . .

25

Terminus area changes of all Northern Hemisphere marine-terminating
glaciers since 2000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

25

Factors controlling terminus position of tidewater glaciers in Hornsund
fjord (Svalbard) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

26

Hypsometric control on basin sensitivity under rising equilibrium line altitudes in the Northern Canadian Arctic Archipelago . . . . . . . . . . . . . . .

27

Greenland ice sheet surface water vapour fluxes from automatic weather
station records . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

27

The control of short-term ice mélange weakening episodes on calving activity at major Greenland outlet glaciers . . . . . . . . . . . . . . . . . . . . . .

28

Some thoughts and observations on basal motion beneath the (still) polythermal McCall Glacier, Alaska . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

28

Impact and evaluation of improved ice surface roughness formulation in
RACMO 2.3p2 on Greenland surface melt modelling . . . . . . . . . . . . . . .

29

Modelling lateral meltwater flow atop the Greenland Ice Sheet’s nearsurface ice slabs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

30

Crystal fabric orientation of the NEGIS ice stream . . . . . . . . . . . . . . . .

30

Changes in Glacial Hydrology in Response to Recent Increases in Surface
Melt on Ellesmere Island, Canadian High Arctic . . . . . . . . . . . . . . . . . .

31

Mass loss of Qaanaaq Ice Cap in northwestern Greenland from 2012 to 2022 32
Frontal ablation modulated by hydropower regulation? A case study from
Austdalsbreen, Western Norway . . . . . . . . . . . . . . . . . . . . . . . . . . . .

32

Glacier geometry and mass change at Sirmilik and Auyuittuq National
Parks, Nunavut, Arctic Canada, 1960-2020 . . . . . . . . . . . . . . . . . . . . .

33

A novel large-scale ice thickness inversion method tested on Kronebreen,
Svalbard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

33

The surge of high-Arctic Chapman Glacier, 1999-2018 . . . . . . . . . . . . .

34

Frontal ablation of Northern Hemisphere glaciers for 2000-2020 . . . . . . .

34

Supraglacial lake evolution on Tracy and Heilprin Glaciers in northwestern
Greenland from 2014 to 2021 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

35

Preface
This year’s IASC Workshop on the Dynamics and Mass Budget of Arctic Glaciers &the IASC Network on Arctic Glaciology Annual Meeting took place at the University Centre Obergurgl, in Obergurgl, Austria, 26-28 January 2023. The workshop
hosted a cross-cutting activity on "Glacier-atmosphere interactions in a warming
and wetting Arctic" and attracted 45 participants representing 12 countries. The
workshop was jointly sponsored by the IASC Cryosphere and Atmosphere Working
Groups, involved in the cross-cutting activity. This also allowed for travel supportof twelve early-career scientists and two keynote speakers.
The general workshop included stimulating sessions on glacier mass balance,
glaciers dynamics, glacier hydrology and glacier calving and frontal ablation. The
cross-cutting activity consisted of two oral presentation sessions, followed by across-cutting discussion session. A poster session covered both the cross-cutting
and general workshop theme. Two keynote lectures were given on the resilience ofGreenland firn to climate warming (Brice Noël) and North-Atlantic cooling and theimpact on Icelandic glacier mass balance (Gudfinna Adalgeirsdottir). Other presentations in the cross-cutting theme among others discussed turbulent heat andmoisture fluxes over a glacier surface (Maurice van Tiggelen, Maiken Kristiansen
Revheim), the Greenland Climate Network (Andreas Ahlstrøm, Jason Box), andthe history of climate change work in Greenland (Jakob Abermann). Other studies looked into climate impacts on glaciers in Norway (Liss Andreassen) and theCanadian Arctic (Danielle Hallé). The cross-cutting discussion focused on how we
can improve collaboration between modellers and observers and between glaciologists and meteorologists. Discussion points e.g. included 1) how we can improve
the representation of glaciers and ice sheets in regional climate models and earthsystem models, 2) changes in large-scale circulation patterns and the impact on
glacier mass balance, 3) rain-on-snow events and the impact on snow, firn andrunoff, 4) remote sensing and in-situ observations of precipitation and snowfall on
Arctic glaciers.
During the open forum meeting, it was decided that the next IASC NAG meeting
will again be held in Obergurgl, Austria, on 22-24 January 2024. The 2025 meeting
will be held in Japan. Furthermore, a number of changes were made to the list ofnational contacts, and the future hybrid meeting format, cross-cutting activities
and content of the website were discussed.
I would like to thank all participants for their contributions to the meeting and I
hope to see you all back next year! Same place and (almost) same time!

Best regards,
Ward van Pelt

Uppsala, Sweden – March 2023
3

Schedule
The meeting takes place at the University Centre in Obergurgl, Austria, 26 - 28
January, 2023.

Wednesday 25 January
ARRIVAL
19:00 - 20:30

DinnerThursday 26 January
08:30 - 09:00

Registration: pick up your name badge and copy of program.
Please upload your presentations for the morning session.

09:00 - 09:05

WelcomeSession I:
Convener:
09:05 - 09:20

Glacier mass balance
Madeline Myers
Glacier geometry and mass change at Sirmilik and Auyuittuq
National Parks, Nunavut, Arctic Canada, 1960-2020 Wai Yin
CheungTrends in Greenland ice sheet observational records:
implications for changing ice volume Jason Box, Baptiste
Vandecrux, Andreas Ahlstrøm, Nanna Karlsson, Adrien Wehrlé
Geodetic mass balance of a small glacier in the Canadian High
Arctic determined from historical aerial photography Dorota
Medrzycka, Luke Copland
15 years Mass Balance Measurements at Freya Glacier,
NE-Greenland Bernhard Hynek, Daniel Binder, Gernot Weyss,
Jakob Abermann, Wolfgang Schöner, Michele Citterio, Signe
LarsenMass loss of Qaanaaq Ice Cap in northwestern Greenland from2012 to 2022 Shin Sugiyama, Kaho Watanabe, Ken Kondo

09:20 - 09:35

09:35 - 09:50

09:50 - 10:05

10:05 - 10:20

10:20 - 10:50

Coffee break

Session II:
Convener:
10:50 - 11:05

Glacier dynamics I
Penelope Gervais
Ice stream flow dynamics of Sermeq Kujalleq observed withdetailed repeated UAV surveys Andrea Kneib-Walter,
Guillaume Jouvet, Martin Lüthi
4

11:05 - 11:20

Some thoughts and observations on basal motion beneath the(still) polythermal McCall Glacier, Alaska Matt Nolan

11:20 - 11:35

Hydrothermal structure of Elfenbeinbreen and Sveigbreen,
Sabine Land, Svalbard, and its changes for Sveigbreen during
2014-2022 Francisco Navarro, Ivan Lavrentiev, Evgeny
Vasilenko, Unai letamendia, Beatriz Benjumea, Alexandr Borisik

11:35 - 15:45

Lunch & ski break

15:45 - 16:15

Coffee break

16:15 - 16:45

Poster introductions(1-2 slides and max. 2 minutes per person)

Convener:

Wesley Van Wychen

16:45 - 18:30

Poster session

19:00 - 20:30

DinnerFriday 27 January
Session III:

Cross-cutting session (part I)

Convener:

Jakob Abermann

09:00 - 09:25[Keynote] Resilience of the Greenland ice sheet firn layer under
future climate warming Brice Noël, Jan Lenaerts, William
Lipscomb, Katherine Thayer-Calder, Michiel van den Broeke

09:25 - 09:40

Evolving Ice Fraction in the Shallow Firn Layer of Devon Ice Cap,
Nunavut between 2011 to 2022 Danielle Hallé, Wesley Van
Wychen, Richard Kelly, David Burgess, Bradley Danielson, Luke
Copland, Peter Bezeau, Brice Noël09:40 - 09:55

Impact and evaluation of improved ice surface roughness
formulation in RACMO 2.3p2 on Greenland surface melt
modelling Maurice Van Tiggelen, Paul Smeets, Carleen
Reijmer, Christiaan van Dalum, Brice Noël, Willem Jan van deBerg, Dirk van As, Jason Box, Robert Fausto, Michiel van den
Broeke09:55 - 10:10

The Greenland Climate Network v.2 - a new era of monitoring
the Greenland ice sheet Andreas Ahlstrøm, Jason Box, Nanna
Karlsson, William Colgan, Robert Fausto, Signe Andersen,
Baptiste Vandecrux, Anja Rutishauser, Penny How, Ken Mankoff,
Jakob Jakobsen, Chris Shields, Allan Pedersen, Michele Citterio,Alexandra Messerli, Anne Solgaard, Signe Larsen, Niels
Korsgaard, Kristian Kjeldsen, Derek Houtz

10:10 - 10:35

Coffee breakSession IV:

Cross-cutting session (part II)

Convener:

Ward van Pelt

10:35 - 11:00[Keynote] North Atlantic cooling and the impact on Icelandic
glacier mass balance Guðfinna Aðalgeirsdóttir, Brice Noël,Finnur Pálsson, Steingrímur Jónsson

11:00 - 11:15

Reconnaissance of Alfred Wegener’s West Greenland Expedition:
bridging a century of climate change work: 1929 to 2022 Jakob
Abermann, Baptiste Vandecrux, Sebastian Scher, Florina
Schalamon, Andreas Trügler, Robert Fausto, Wolfgang Schöner

11:15 - 11:30

Present changes of Jostedalsbreen, Norway’s largest ice cap
Liss Marie Andreassen, Mette Gillespie, Kjetil Melvold, Kamilla
Sjursen, Benjamin Robson, Hallgeir Elvehøy, Bjarne Kjøllmoen,
Jacob Yde

11:30 - 12:00

Cross-cutting discussion

12:00 - 15:45

Lunch & ski break

15:45 - 16:15

Coffee break

Session V:

Glacier hydrology

Convener:

Maiken Kristiansen Revheim

16:15 - 16:30

Modelling lateral meltwater flow atop the Greenland Ice Sheet’s
near-surface ice slabs Nicole Clerx, Horst Machguth

16:30 - 16:45

Greenland slush limits; comparing remote sensing and RCM
simulations Horst Machguth, Andrew Tedstone

16:45 - 17:00

Glacier recession vs. water drainage at a forefield(Werenskioldbreen, Svalbard) Katarzyna Stachniak, Krzysztof
Janik, Dariusz Ignatiuk, Elzbieta Łepkowska, Jacek Jania

17:00 - 17:15

Supraglacial lake evolution on Tracy and Heilprin Glaciers innorthwestern Greenland from 2014 to 2021 Yefan Wang, Shin
Sugiyama

17:15 - 17:20

Short break

17:20 - 18:30

IASC Network on Arctic Glaciology – Open forum meeting

19:00 - 20:30

DinnerSaturday 28 January
Session VI:

Glacier dynamics II

Convener:

Will Kochtitzky

09:00 - 09:15

Dynamics throughout a complete surge of Iceberg Glacier onwestern Axel Heiberg Island, Canadian High Arctic Benoît
Lauzon, Luke Copland, Wesley Van Wychen, William Kochtitzky,
Robert McNabb, Dorthe Dahl-Jensen

09:15 - 09:30

Little Kluane Glacier, Yukon: a tributary-trunk surge BrittanyMain, Luke Copland, Will Kochtitzky, Sergey Samsonov, Gwenn
Flowers, Christine Dow

09:30 - 09:45

Recent patterns of velocity and elevation change, and theirassociated drivers, Hubbard Glacier, Alaska Courtney Bayer,
Wesley Van Wychen, Anna Wendleder

09:45 - 10:00

Terminus area changes of all Northern Hemispheremarine-terminating glaciers since 2000 Luke Copland, Will
Kochtitzky

10:00 - 10:15

Crystal fabric orientation of the NEGIS ice stream Olaf Eisen,
Tamara Annina Gerber, David Lilien, Nicholas Rathmann, StevenFranke, Tun Jan Young, Fernando Valero-Delgado, Reza Ershadi,
Reinhard Drews, Ole Zeising, Angelika Humbert, Nicolas Stoll,
Ilka Weikusat, Aslak Grinsted, Christine Hvidberg, Daniela
Jansen, Heinrich Miller, Veit Helm, Daniel Steinhage, Charles
O’Neill, John Paden, Prasad Gogineni, Dorthe Dahl-Jensen

10:15 - 10:45

Coffee break

Session VII:

Frontal processes

Convener:

Erika Brummel

10:45 - 11:00

Calving response to the propagation of a speedup pulse throughthe ice stream of Sermeq Kujalleq in Kangia (Jakoshavn Isbræ),Greenland Adrien Wehrlé, Martin Lüthi, Andrea Walter, Ana
Nap, Guillaume Jouvet, Hugo Rousseau, Fabian Walte

11:00 - 11:15

Factors controlling terminus position of tidewater glaciers inHornsund fjord (Svalbard) Małgorzata Błaszczyk, Mateusz
Moskalik, Mariusz Grabiec, Jacek Jania, Waldemar Walczowski,
Tomasz Wawrzyniak, W. Tad Pfeffer

11:15 - 11:30

The control of short-term ice mélange weakening episodes on
calving activity at major Greenland outlet glaciers Martin
Lüthi, Adrien Wehrlé

11:30 - 11:45

Frontal ablation modulated by hydropower regulation? A casestudy from Austdalsbreen, Western Norway Thorben Dunse,
Hallgeir Elvehøy, Even Loe, Gernot Seier, Jakob Aberman, Mette
Kusk Gillespie, Jacob Yde

11:45 - 12:00

Frontal ablation of Northern Hemisphere glaciers for 2000-2020
Will Kochtitzky, Luke Copland, Wesley Van Wychen, Romain
Hugonnet, Regine Hock, Julian Dowdeswell, Toby Benham, Tazio
Strozzi, Andrey Glazovsky, Ivan Lavrentiev, David Rounce,
Romain Millan, Alison Cook, Abigail Dalton, Hester Jiskoot, Jade
Cooley, Jacek Jania, Francisco Navarro

12:00

Final words
followed by lunch / skiing / side events / early departure

19:00 - 20:30

DinnerPosters• Multidecadal reconstruction of the surface mass balance of an Arctic glacierusing reanalysis data, Anna Rohrböck, Bernhard Hynek, Leopold
Haimberger, Wolfgang Schöner• Crustal Uplift: a regional response to contemporary ice mass loss Bradley
Danielson, David Burgess, Thomas James, Maximilian Lauch, Michael
Craymer• Changes in the extent and velocity of the Hornbreen - Hambergbreen system(S Spitsbergen) Dawid Saferna, Małgorzata Błaszczyk, Bogdan Gadek• Assessing the 2021-2022 surge behaviour of Lowell Glacier Erika Brummell,
Luke Copland, Christine Dow, Wesley Van Wychen, Dorota Medrzycka, Adam
Garbo
• Reconstructing the past two surges of Fisher Glacier, Yukon GabrielPartington, Luke Copland, Dorota Medrzycka, William Kochtitzky, Benoît
Lauzon• Vertical ice - morphology of the terrestrial ice margin in Greenland Jakob
Steiner, Jakob Abermann, Rainer Prinz• Hypsometric control on basin sensitivity under rising equilibrium line altitudes
in the Northern Canadian Arctic Archipelago Madeline Myers, Laura Thomson• Greenland ice sheet surface water vapour fluxes from automatic weather
station records Maiken Kristiansen Revheim, Jason Box, Baptiste
Vandecrux, Christine Hvidberg• Changes in Glacial Hydrology in Response to Recent Increases in Surface Melton Ellesmere Island, Canadian High Arctic Penelope Gervais, Luke Copland• A novel large-scale ice thickness inversion method tested on Kronebreen,
Svalbard Thomas Frank, Ward van Pelt
• The surge of high-Arctic Chapman Glacier, 1999-2018 Wesley Van Wychen,
Hester Jiskoot

8

Participants
1. Adrien Wehrlé (adrien.wehrle [at] hotmail.fr)
University of Zurich, Switzerland
2. Andrea Kneib-Walter (andrea.walter [at] geo.uzh.ch)
University of Zurich, Switzerland
3. Andreas Ahlstrøm (apa [at] geus.dk)
GEUS, Denmark
4. Anna Rohrböck (anna.rohrboeck [at] zamg.ac.at)
ZAMG, Austria
5. Anna Wendleder (anna.wendleder [at] dlr.de)German Aerospace Center, Germany
6. Benoît Lauzon (blauz052 [at] uottawa.ca)
University of Ottawa, Canada
7. Bernhard Hynek (bernhard.hynek [at] zamg.ac.at)
ZAMG, Austria
8. Bradley Danielson (bradley.danielson [at] nrcan-rncan.gc.ca)
Natural Resources Canada, Canada
9. Brice Noël (b.p.y.noel [at] gmail.com)
University of Liège, Belgium
10. Brittany Main (bmain018 [at] uottawa.ca)
University of Ottawa, Canada
11. Carleen Reijmer (c.h.tijm-reijmer [at] uu.nl)
Utrecht University, The Netherlands
12. Courtney Bayer (cabayer [at] uwaterloo.ca)
University of Waterloo, Canada
13. Danielle Hallé (dhalle [at] uwaterloo.ca)
University of Waterloo, Canada
14. Dawid Saferna (dawid.saferna [at] o365.us.edu.pl)
University of Silesia in Katowice, Poland
15. Dorota Medrzycka (dorota.medrzycka [at] uottawa.ca)
University of Ottawa, Canada
16. Erika Brummell (ebrum084 [at] uottawa.ca)
University of Ottawa, Canada
17. Francisco Navarro (francisco.navarro [at] upm.es)
Universidad Politécnica de Madrid, Spain
18. Gabriel Partington (gabrielpartington [at] gmail.com)
University of Ottawa, Canada
19. Guðfinna Aðalgeirsdóttir (gua [at] hi.is)
University of Iceland, Iceland
20. Heinz Miller (heinrich.miller [at] awi.de)
AWI, Germany
21. Horst Machguth (horst.machguth [at] unifr.ch)
University of Fribourg, Switzerland
22. Jakob Abermann (jakob.abermann [at] uni-graz.at)9Graz University, Austria
23. Jakob Steiner (jakob.steiner [at] uni-graz.at)Graz University, Austria
24. Jason Box (jeb [at] geus.dk)
Geological Survey of Denmark and Greenland, Denmark
25. Katarzyna Stachniak (katarzyna.stachniak.csp [at] gmail.com)
University of Silesia in Katowice, Poland
26. Lindsey Nicholson (lindsey.nicholson [at] uibk.ac.at)University of Innsbruck, Austria
27. Liss Marie Andreassen (lma [at] nve.no)
NVE, Norway
28. Luke Copland (luke.copland [at] uottawa.ca)
University of Ottawa, Canada
29. Madeline E. Myers (19mem7 [at] queensu.ca)
Queen’s University, Canada
30. Małgorzata Błaszczyk (malgorzata.blaszczyk [at] us.edu.pl)
University of Silesia in Katowice, Poland
31. Maiken Kristiansen Revheim (maiken.revheim [at] outlook.com)
Geological Survey of Denmark and Greenland, Denmark; Niels Bohr
Institute, Copenhagen University, Denmark
32. Martin Lüthi (martin.luethi [at] geo.uzh.ch)
University of Zurich, Switzerland
33. Matt Nolan (matt [at] drmattnolan.com)
Serving Earth Science Inc., USA
34. Maurice Van Tiggelen (m.vantiggelen [at] uu.nl)
Utrecht University, The Netherlands
35. Michael Kuhn (michael.kuhn [at] uibk.ac.at)University of Innsbruck, Austria
36. Nicole Clerx (nicole.clerx [at] unifr.ch)
University of Fribourg, Switzerland
37. Olaf Eisen (oeisen [at] awi.de)
AWI, Germany
38. Penelope Gervais (pgerv058 [at] uottawa.ca)
University of Ottawa, Canada
39. Shin Sugiyama (sugishin [at] lowtem.hokudai.ac.jp)
Hokkaido University, Japan
40. Thorben Dunse (Thorben.Dunse [at] hvl.no)
Western Norway University of Applied Sciences, Norway
41. Wai Yin Cheung (w.cheung [at] queensu.ca)
Queen’s University, Canada
42. Ward van Pelt (ward.van.pelt [at] geo.uu.se)
Uppsala University, Sweden
43. Wesley Van Wychen (wvanwychen [at] uwaterloo.ca)
University of Waterloo, Canada
44. Will Kochtitzky (wkochtitzky [at] une.edu)
University of New England, USA
45. Yefan Wang (wangyefan [at] lowtem.hokudai.ac.jp)
Hokkaido University, Japan

Minutes of the IASC-NAG open forum
meeting
Chair: Ward van Pelt
Minutes: Erika Brummell
Invited to attend: all participants of the workshop.
Agenda
1.
2.
3.
4.
5.
6.
7.

Recent developments
IASC Network on Arctic Glaciology
Cross-cutting activity
Chair, vice-chair and national contacts
Upcoming meetings
Hybrid solutions
Website promotion

Recent developments
Ward van Pelt presents an overview of activities of the Network on Arctic glaciology since the last (online) meeting in January 2022. Activities included (successful) application for funding from IASC for a cross-cutting activity (Feb-May 2022),
meeting preparation, search for keynotes (Jun-Aug 2022), registration abstract
submission (Sep-Nov 2022), application for IASC funding for 2024 meeting (Dec2022), final meeting preparations (Dec 2022-Jan 2023).
IASC Network on Arctic Glaciology
An overview is given of the general aims and objectives of the IASC Network on
Arctic Glaciology, and its history. Main objectives of the annual meetings are to1) present and discuss new research, 2) coordinate fieldwork, 3) discuss future
project ideas and collaboration, 4) networking.
Cross-cutting activity
It is discussed that a proposal for funding of a cross-cutting activity was submitted
to IASC in December 2022. Topic: "Societal impacts of glacier and snow changes
in a warming Arctic". IASC working groups involved: Atmosphere, Cryosphere andSocial and Human. The activity was presented to IASC WG members on January
27 and decision will likely follow in March. The activity will look into societal impacts of Arctic glacier retreat (e.g. sea level rise, glacier outburst floods, glacier
tourism, increased runoff and fjord processes) and trends in seasonal snow in
the Arctic (e.g. rain-on-snow events, extreme precipitation, hydropower potential,
snow cover duration mobility and avalanches). Finally, also contributions on the
topic of mental health impacts of glacier and snow changes will be welcomed. ReC11000. Early-career scientists will be engaged in the planning,quested funding: =execution and reporting of the meeting.
Engaging scientists from the different disciplines in the cross-cutting activity
will be a challenge that will require effort from the entire network. Any suggestions

11

on whom to best involve and approach are welcomed and can be shared with thechair.
Chair, vice-chair and national contacts
The chair (Ward van Pelt) and vice-chair (Wesley Van Wychen) indicated interestin continuing with their role and this was supported by the participants. The list ofnational contacts was then discussed and a few suggestions for changes emerged.
A confirmed change includes a new Polish contact (Malgorzata Blaszczyk). Othersuggestions include Will Kochtitzky as new national contact for the US, Pete Nienow
as UK national contact, Nina Kirchner as national contact for Sweden and BriceNoël as new national contact for Belgium.
Upcoming meetings
Poland withdrew as potential candidate for organizing the IASC NAG meeting in
2024 which left only Japan and Austria as the remaining options. After a voteand an indicated preference by Shin Sugiyama to organize the meeting in 2025,
it was decided that the meeting in 2024 will be held in Obergurgl, Austria, onJanuary 22-24. The meeting in 2025 will take place in Sapporo, Japan. There wasa suggestion for future meetings to be held during the weekend, to reduce overlap
with teaching obligations.
To have a bit more space at the University Center, it was suggested to increase
the number of pre-booked rooms. After a chat with the University Center staff it
was agreed that 35 double rooms will be available to us in 2024 (was 24 in 2023).
We can still decide to reduce this amount until autumn.
Hybrid solutions
Several hybrid meeting solutions were presented for future meetings and as inprevious discussions the preference is still for the ’hybrid-medium’ variant, which
implies a physical meeting with live-streamed presentations. This is the sameformat as during the current meeting. It was suggested to more broadly advertisethe live-stream to increase online attendance.
Website promotion
The state of the current website (nag.iasc.info) was discussed. It was argued
that no major changes to the layout would be necessary as it is not worth thetime investment. Most people regard the website as an archive and only use
the workshop webpage for information regarding the upcoming meeting. One
suggestion was to update the pictures with newer photos. It was also suggested
to add next year’s dates to the workshop page.
The abstract book was discussed and there was no interest to return to the extended abstract book. One suggestion was to add references to published papers.
It was also suggested to add an ISBN number, which could help some with funding
applications.

Abstracts
Calving response to the propagation of a speedup pulse
through the ice stream of Sermeq Kujalleq in Kangia(Jakoshavn Isbræ), Greenland
Adrien Wehrlé1 , Martin P Lüthi1 , Andrea Walter1 , Ana Nap1 , Guillaume Jouvet2 , Hugo
Rousseau1 , Fabian Walter3
1 University of Zurich, Switzerland
2 University of Lausanne, Switzerland
3 WSL, Switzerland

Sermeq Kujalleq in Kangia (Jakobshavn Isbræ), Greenland is one of the most studied
glaciers in the world mainly due to its recent retreat associated with extremely fast ice
stream flow and high solid ice discharge. However, large limitations remain in the understanding of its short-term dynamics as the study of sub-daily variations, undetectablein spaceborne observations, requires high-rate field measurements that are challenging
to acquire. Here, we present glacier surface velocities computed in Post-Processed Kinematic (PPK) mode from eight autonomous GNSS stations deployed in July 2022 along theice stream at a distance of 4 to 30 kilometers from the calving front. During this field
campaign, we identified an 8-hour-long glacier speedup recorded at all GNSS stations
representing up to 10.5% of the pre-event velocity, followed by a 12-hour-long slowdownof similar magnitude. We further found the peak velocity was first measured at a GNSS
station 15.8km away from the calving front, then further recorded at the three other downstream GNSS stations with a positive time lag corresponding to a 2.8km/h downstream
wave propagation speed. At the station the closest to the calving front, the timing of peakvelocity corresponded to the occurrence of large-scale calving events. We further present
line-of-sight glacier surface velocities determined along three shear margin transects witha terrestrial radar interferometer deployed simultaneously with the GNSS array. We show
a simultaneous response of the fast- and slow-moving ice across all profiles, the glacier
speedup being recorded throughout the entire length of the shear margins up to almost
immobile ice. As a result, we determined the ice stream to have widened by more than
200 meters during the event.

Ice stream flow dynamics of Sermeq Kujalleq observedwith detailed repeated UAV surveys
Andrea Kneib-Walter1 , Guillaume Jouvet2 , Martin P. Lüthi1
1 University of Zürich, Switzerland
2 University of Lausanne, Switzerland

Outlet glaciers and ice streams transport ice from the ice sheets to the ocean. Sermeq
Kujalleq (JI, Jakobshavn Isbræ) is one of the largest and the most dynamic ice stream of
the Greenland Ice Sheet with velocities up to 40 m/day. JI’s ice stream is separated from13the slower flowing ice sheet by a highly crevassed shear margin. This project aims at understanding the complex glacier flow and the processes occuring at the shear margin andthe calving front of JI. Such processes are often neclected in numerical models inducing
uncertainties in projections of the ice sheet evolution. Drone photogrammetrical surveys
were conducted in July 2022 at JI within the framework of the COEBELI project along otherfield measurements including in-situ GPS, GPRI, seismometers and time-lapse imagery.
Despite challenging weather conditions and constraints due to flying restrictions, we acquired more than 10 repeated long-range flight surveys over the calving front of JI as well
as along and perpendicular to the shear margins during about two weeks. As a result,
we produced a large imagery data set, which was processed to infer high-resolution orthoimages and digital elevation models (DEM). Comparing the different products enables
us to estimate changes in surface topography and ice dynamics. With this we can capture
processes such as hydrological or tidal effects on the horizontal and vertical ice dynamics,
speed-up events or the reaction of the glacier to large calving events. Several such large
calving events occurred during the observation period enabling us to investigate the interaction between frontal processes and the ice flow dynamics of the ice stream. Having
several ice stream profiles with increasing distance to the calving front allows us to further investigate how far upstream frontal processes can influence ice stream dynamics.

The Greenland Climate Network v.2 - a new era of monitoring the Greenland ice sheet
Andreas Ahlstrøm1 , Jason Box1 , Nanna Karlsson1 , William Colgan1 , Robert Fausto1 ,Signe Andersen1 , Baptiste Vandecrux1 , Anja Rutishauser1 , Penny How1 , Ken Mankoff1 ,Jakob Jakobsen1 , Chris Shields1 , Allan Pedersen1 , Michele Citterio1 , Alexandra Messerli2 ,Anne Solgaard1 , Signe Larsen1 , Niels Korsgaard1 , Kristian Kjeldsen1 , Derek Houtz3
1 GEUS, Denmark
2 Asiaq Greenland Survey, Denmark
3 WSL, Switzerland

The Greenland Ice Sheet plays an important role in the global climate system by influencing the global radiation budget and the circulation of the atmosphere and ocean,with a contribution of 16 mm to global sea level rise in the last 50 years and accelerating. While satellites currently enable deriving total ice mass changes, ice movement
and ice sheet elevation change and regional climate models provide constraint for the
key mass fluxes of snow accumulation and meltwater runoff, only in-situ observations
can reliably reveal if these remote assessments are accurate. Automatic weather stations (AWS) deliver ground-truth near real-time data for the study of local surface massbalance processes, for the evaluation of satellite-derived products and regional climate
models and for assimilation within weather forecast models. The Greenland Climate Network, currently consisting of 16 AWS on the Greenland ice sheet, primarily established in
the period 1995 to 1999, with the Swiss Camp station beginning June 1990, through theinitiative of the late Prof. Konrad Steffen. Prof. Steffen led the effort gaining funding fromNASA Polar Program, the US National Science Foundation and the Swiss Federal Institutefor Forest, Snow and Landscape until 2020, at which point the Geological Survey of Denmark and Greenland (GEUS) was invited to continue the operation. With GEUS, partneringwith Asiaq Greenland Survey, GC-Net will become part of a Greenland-wide network of 40
AWS on Greenland ice, consisting of 16 AWS situated in the accumulation area and 24 in
the ablation area, with 34 AWS placed on the ice sheet and 6 on local glaciers and ice
caps. Here, we present the development initiated to carry GC-Net into the future, describing changes in instrumentation, open data processing and availability policies under the
FAIR principles, field procedures as well as novel activities and initiatives reaching beyond
AWS maintenance.

Multidecadal reconstruction of the surface mass balance of an Arctic glacier using reanalysis data
Anna Rohrböck1 , Bernhard Hynek1 , Leopold Haimberger2 , Wolfgang Schöner3
1 ZAMG, Austria
2 Universität Wien, Austria
3 Universität Graz, Austria

The mass balance of Freya glacier in Northeast Greenland is monitored since 2007. Our
goal is to extend the understanding of the mass balance of Freya glacier into the past, byusing reanalysis data to reconstruct the surface mass balance. The aim of this study is
to use statistical downscaling to approximate the glacier surface conditions from reanalsysis data and output of regional climate models. The rate of mass loss is determined toevaluate if effects of climate change have an impact in recent years. To examine the data
for spatial variability, data from the climate station in Zackenberg is compared with datafrom the automatic weather station (AWS) on Freya glacier. The spatial downscaling isdone with the ERA5-Land hourly data from 1950 to present and the Arctic regional reanalysis from 1991 to present. The former enables to reconstruct the surface mass balance
further into the past, the latter, however, provides a higher spatial resolution.

Dynamics throughout a complete surge of Iceberg Glacier
on western Axel Heiberg Island, Canadian High ArcticBenoît Lauzon1 , Luke Copland1 , Wesley Van Wychen2 , William Kochtitzky1,3 , Robert
McNabb4 , Dorthe Dahl-Jensen5,6
1 University of Ottawa, Canada
2 University of Waterloo, Canada
3 University of New England, USA
4 Ulster University, UK
5 University of Manitoba, Canada
6 University of Copenhagen, Denmark

This study provides the first comprehensive reconstruction of the dynamics of Iceberg
Glacier, located on western Axel Heiberg Island, and reveals detailed observations of acomplete surge for the first time in the Canadian Arctic. Historical aerial photographs,
declassified intelligence satellite photographs, optical satellite imagery, and synthetic
aperture radar data were used to quantify changes in terminus position, ice velocity, andglacier thickness since the 1950s. A surge initiated at the terminus in 1981 and terminated in 2003, suggesting an active phase duration of 22 years. High surface velocities,
peaking at 2300 m a−1 at the terminus in 1991, were accompanied by a terminus advance of >7 km from 1981 to 1997 and a large transfer of mass down-glacier, causing
significant median surface elevation changes reaching >3 ± 1 m a−1 across the entire
trunk width. We suggest that the retreat from a pinning point, flotation of the terminus,
and the removal of sea-ice from the ice front likely contributed to surge initiation.The
ensuing quiescent period has seen a continual decrease in flow rates to an average centreline velocity of 11.5 m a−1 in 2020–2021, a gradual steepening of the glacier surface,and a >2.5 km terminus retreat.

15 years Mass Balance Measurements at Freya Glacier,
NE-Greenland
Bernhard Hynek1 , Daniel Binder2 , Gernot Weyss1 , Jakob Abermann3 , Wolfgang Schöner3 ,Michele Citterio4 , Signe H. Larsen4
1 ZAMG, Austria
2 University Potsdam, Germany
3 University of Graz, Austria
4 GEUS, Denmark

We present main results of 15 yeas of glaciological monitoring at Freya Glacier inNortheast Greenland next to Zackenberg Research Station. The monitoring started in2007 with direct seasonal observations, and encludes now an automatic weather stationand two automatic cameras. Elevation changes and geodetic mass balance between
2013 and 2021 can be determined from two high resolution DEMs using a structure frommotion approach, and bedrock topography is deduced from a GPR survey in 2008.

Crustal Uplift: a regional response to contemporary ice
mass loss
Bradley Danielson1 , David Burgess2 , Thomas James2 , Maximilian Lauch3 , Michael Craymer4
1 Natural Resources Canada, Canada
2 Geological Survey of Canada, Canada
3 University of Victoria, Canada
4 Canadian Geodetic Survey, Canada

Fluctuations in mass of the Earths glaciers, ice caps and ice sheets can have significant, real-time changes in vertical land motion, which in turn can affect relative sea-levelrise, and changes to the Earths geoid, ie. model of global mean sea level. Canada holdsa large concentration of ice mass, yet the impacts of glacier mass loss on vertical landmotion of Canada’s land mass are currently unknown. The Geological Survey of Canada’s
National Glaciology Project is currently in the process of establishing a network of GNSS
stations on bedrock locations adjacent to monitored ice caps and glaciers in Canada, inorder to quantify rates of vertical land motion in response to ongoing increases in massloss from Canada’s glaciers. These measurements are required for regional assessmentsof glacier mass change, generating robust projections of relative sea-level rise, and constraing Canada’s near real-time geoid model. This poster will outline the projects goals,
current status, and preliminary observations.

Resilience of the Greenland ice sheet firn layer under
future climate warming
Brice Noël1 , Jan T. M. Lenaerts2 , William Lipscomb3 , Katherine Thayer-Calder3 , Michielvan den Broeke4
1 University of Liège, Belgium
2 Department of Atmospheric and Oceanic Sciences, University of Colorado Boulder, Boulder, CO,USA
3 Climate and Global Dynamics Laboratory, National Center for Atmospheric Research, Boulder, CO,USA
4 Institute for Marine and Atmospheric research Utrecht, Utrecht University, Utrecht, Netherlands

Firn, the compressed snow layer covering 90% of the Greenland ice sheet (GrIS), currently retains about half of rain and meltwater through refreezing, hence mitigating massloss from surface runoff. The loss of firn could mark a tipping point for sustained GrIS massloss since decades to centuries of cold summers would be required to rebuild a healthyfirn buffer. Such threshold has not been passed for the GrIS, at least since the beginningof the satellite era.
In contrast, Greenland peripheral ice caps, detached from the main ice sheet, andother neighbouring Arctic glaciers have progressively lost their firn buffer since the mid1990s. First, we identify the drivers of reduced firn refreezing capacity for these glaciersand investigate the impact on contemporary mass loss. Next, we explore the resilienceof GrIS firn in a future warming climate.
To that end, we use climate simulations under multiple emission scenarios to project
the long-term GrIS firn layer evolution in the period 1850-2300. We predict that GrIS firn
refreezing stabilises under low warming scenarios, while it peaks and permanently declines under high-end warming trajectories in the early 22nd century. Finally, we quantify
the warming required for the GrIS to cross this threshold and estimate the resulting ice
sheet contribution to global sea level rise.

Little Kluane Glacier, Yukon: a tributary-trunk surge
Brittany Main1 , Luke Copland1 , Will Kochtitzky2 , Sergey Samsonov3 , Gwenn Flowers4 ,Christine Dow5
1 University of Ottawa, Canada
2 University of New England, USA
3 Canadian Centre for Mapping and Earth Observations, Canada
4 Simon Fraser University, Canada
5 University of Waterloo, Canada

Little Kluane Glacier (unofficial name), a previous tributary of Kluane Glacier, Yukon,
underwent a dramatic surge from 2015-18. No previous reports of surges from this glacier
are available, so the characteristics of the quiescent phase and recent active phase werereconstructed using a combination of historical air photos, remote sensing and field observations since the 1940s. Only a single full surge was identified in this period, although
it appears that a partial surge occurred between 1963 and 1972.
Mapping of looped moraines from 1951 to present suggests that at least 6 surges
have initiated from the northern tributary in the historical past. Terminus positions were
mapped using a combination of historical aerial imagery and optical satellite imagery(Landsat series, Sentinel-2, Planet), which show a long-term retreat from 1949-2017, followed by rapid advance of over 2 km in 2018. Velocities of up to 5000 m yr-1 during thesurge were obtained from speckle tracking of synthetic aperture radar images, and longterm annual average velocities were obtained from the ITS_LIVE dataset. Differencing
of repeat Digital Elevation Models (DEMs) created from stereo satellite imagery demonstrate that the most recent surge initiated from near the top of the accumulation area in
the northern tributary beginning in 2015, which then triggered a surge of the main trunk
from 2017-18. During the surge the surface lowered by 100-150 m in the northern tributary, along with a corresponding thickening in the receiving zone. This study provides anexample of a surge-type glacier that is highly influenced by valley geometry, as well as
insight into how a tributary surge can instigate fast flow in the main trunk.

Recent patterns of velocity and elevation change, andtheir associated drivers, Hubbard Glacier, Alaska
Courtney Bayer1 , Wesley Van Wychen1 , Anna Wendleder2
1 University of Waterloo, Canada
2 German Aerospace Centre (DLR), Germany

Hubbard Glacier is a large, Alaskan tidewater terminating outlet measuring 123 km in
length, making it both the biggest calving glacier inside North America and the biggest
non-polar tidewater glacier globally. Previous research has found that Hubbard Glacierexperiences a unique seasonal cycle in glacier flow, with distinct slowdowns observed in
the late summer and variations in flow speeds of up to 6 m d−1 through the year. To
this date however, the quantification of this seasonality has been sparsely studied largely
due to a lack of available datasets to enable its characterization. But, with the recent
launch of a number of openly available remote sensing datasets, this study investigatesthe seasonality of Hubbard Glacier in unprecedented detail. Specifically, using surface
velocities derived from SAR (Sentinel-1, TerraSAR-X, ERS-1/ERS-2) and optical imagery(Landsat, Sentinel-2), Hubbard Glacier’s flow speeds are detailed at the highest temporal
resolution possible to allow for an in-depth exploration of its seasonality. This work aims todensify Hubbard Glacier’s seasonality record and extend velocity observations to presentday. The velocity trends are compared to temperature reanalysis data to determine links
between climate and flow speeds, which are used to hypothesize how Hubbard Glacier’s
velocity may evolve in the future with a warming climate. Elevation change of Hubbard
Glacier is also quantified over the 2000-2020 period (in five-year epochs). This allows
us to determine if thickening or thinning of the glacier has occurred and how glacier
dynamics may be responsible for the observed geometry changes. This research is amajor update of our knowledge of how Hubbard Glacier is behaving dynamically andof critical importance for understand how climate change may impact large tidewater
glaciers in Alaska and elsewhere.

Evolving Ice Fraction in the Shallow Firn Layer of Devon
Ice Cap, Nunavut between 2011 to 2022
Danielle Hallé1 , Wesley Van Wychen1 , Richard Kelly1 , David Burgess2 , Bradley Danielson2 ,Luke Copland3 , Peter Bezeau4 , Brice Noël5
1 University of Waterloo, Canada
2 Geological Survey of Canada, Canada
3 University of Ottawa, Canada
4 Alberta Environment and Parks, Canada
5 Utrecht University, The Netherlands

The firn layer of glaciers and ice caps is important for absorbing and storing melt water
through infiltration and refreezing within the porous material. As meltwater refreezes andcreates larger ice layers within the firn it can inhibit the future abilitity of the firn layer tostore melt water. Monitoring the evolution of ice fractions within the firn layer over time
gives important insights into the intensity and severity of melt, melt water storage andimpacts of a warmer climate. The objective of this project is to evaluate how the firn layer
on Devon Ice Cap has responded in the past two decades to a more variable climate,which has consisted of some of the warmest periods on record in the Canadian Arctic
Archipelago (CAA). Results will be presented from four field campaigns on Devon Ice Cap,
where shallow firn cores were extracted along two transects in spring 2012, 2018, 2021
and 2022. Between 2012 and 2022, the ice fraction within the first 200 cm of the firn layer
was observed to decrease by 40% at the lowest elevation site (1400 m a.s.l) and by 9%at the highest elevation site (1800 m a.s.l). Across all sites, ice content had decreased,
and the content of icy and fine-grain firn has increased. The results of this study show thevariability of climate change in the CAA and specifically how surface glacier changes in a
warming climate are responding in a non-linear manner.

Changes in the extent and velocity of the Hornbreen Hambergbreen system (S Spitsbergen)
2
Dawid Saferna1 , Małgorzata Błaszczyk2 , Bogdan Gadek
˛
1 University of Silesia in Katowice, Poland
2 University of Silesia in Katowice

The ongoing warming in the Arctic contributes to increased ablation of glaciers, theirretreat, and changes in dynamics. Hornbreen and Hambergbreen are the two tidewater
glaciers that close the Hornsund fiord (southern Svalbard). Their progressive recession
may open the strait between the Torell Land and Sørkapp Land, impacting the regional
environment. This study aimed to determine the long-term and seasonal velocities andpositions of glaciers’ termini based on remote sensing data and their relations with climatic and oceanographic factors during the period 1985 – 2021. Velocities were derived
from 129 satellite scenes from different sensors (Landsat 5, 7, 8, ASTER, and Sentinel2) with a feature tracking method (Glacier Image Velocimetry software). This method
splits successive images into chips and compares them by searching for the same surface features (e.g. crevasses), then calculates velocity by dividing displacement withtime between the acquisition of scenes. Glacier Termini Tracking plug was used to calculate the fluctuation of the glacier extent with a 2-dimension method (non-linear). Climaticand oceanographic data were retrieved from the Polish Polar Station (air temperature,
precipitation, positive degree days) and the European Space Agency (sea surface temperature) databases. The results show an increased rate of the average annual velocity of
2.85 m/year for the Hornbreen and 0.8 m/year for the Hambergbreen. Differences in theannual velocities are manifested in the time delay of the maximum speed on the Hambergbreen compared to the Hornbreen. The statistically significant correlations between
the rate of changes of the front positions, the sea surface temperature, and the seasonal
sum of the positive degree days were also proven. According to the studies, the openingof the Hornsund strait is expected in 2053.

Geodetic mass balance of a small glacier in the Canadian High Arctic determined from historical aerial photography
Dorota Medrzycka1 , Luke Copland1
1 University of Ottawa, Canada

Despite rapid losses of glacier ice cover in the Canadian Arctic, there are few detailed
studies concerning the geodetic mass balance of small glaciers in the region over multidecadal timescales. In this study, we assess the long-term changes in ice extent anddetermine the geodetic mass balance of Bowman Glacier, a small remnant ice mass in
Tanquary Fiord, northern Ellesmere Island. Using historical and recent aerial photography
and structure from motion (SfM) photogrammetry coupled with multiview stereo (MVS)
techniques, we reconstruct glacier surface topography in 1959 and 2018, and calculate
ice surface elevation change over six decades. This is combined with optical satellite
imagery to reconstruct the evolution in extent of the ice cap over the past 60 years, andground penetrating radar measurements of ice thickness to estimate the remaining ice
volume.
Between 1959 and 2020, Bowman Glacier lost 78% of its original extent (reducing
from 2.75 km2 to 0.61 km2), while average annual area loss rates have nearly tripled
in the past two decades. Over the 1959–2018 period, glacier-wide ice thickness change
averaged -22.7 ± 4.7 m, corresponding to a mean specific annual mass balance of -347.0± 71.4 mm w.e. a−1 . Bowman Glacier currently consists of several stagnating ice masses.
Projecting the average rates of area and volume change into the future indicates theglacier will likely entirely disappear between 2030 and 2060. This study demonstrates
the use of SfM-MVS processing techniques to generate elevation products from 1950s60s historical photographs in the Canadian Arctic, which creates the potential to extend
regional observations of ice elevation and glacier volume change prior to the satellite
record.

Assessing the 2021-2022 surge behaviour of Lowell Glacier
Erika Brummell1 , Luke Copland1 , Christine Dow2 , Wesley Van Wychen2 , Dorota Medrzycka1 ,Adam Garbo1
1 University of Ottawa, Canada
2 University of Waterloo, Canada

The St. Elias Mountains, located between Alaska, British Columbia and the Yukon contains a significant number of surge-type glaciers, of which Lowell Glacier is one of thelargest. There is evidence to suggest that Lowell Glacier has repeatedly surged overtime, with raised beaches and mega bed landforms indicating that previous surges during
the neoglacial blocked the flow of Alsek River and resulted in catastrophic downstream
floods. In this study we report on the ongoing surge of Lowell Glacier, which appears
to have started in 2021. Using a combination of satellite images and high-resolution air
photos the surge initiation can be identified near the terminus, while further observation
indicates that the surge propagated upglacier over time. Glacier velocity mapping fromthe ITS_LIVE dataset, pairs of Radarsat Constellation Mission images, and in situ GNSS
receivers indicate that velocities reached >10 m day−1 in the lower ablation area and >4
m day−1 in the upper ablation area in summer 2022. Changes in glacier extent recorded

by satellite imagery indicate that the terminus advanced by approximately 1.36 km between summer 2021 and summer 2022, reaching a peak position in July 2022. Historical
air photos and satellite images indicate that the glacier previously surged around 194850, 1968-70, 1983-84, 1997-98 and 2009-10. The current surge follows the pattern of ageneral reduction in the period between each subsequent surge since 1948, as well as a
reduction in the maximum terminus extent reached during each surge. These results provide new insights into the surge dynamics of Lowell Glacier, while improving knowledgeof regional surge history.

Hydrothermal structure of Elfenbeinbreen and Sveigbreen, Sabine Land, Svalbard, and its changes for Sveigbreen during 2014-2022
Francisco Navarro1 , Ivan Lavrentiev2 , Evgeny Vasilenko3 , Unai letamendia1 , Beatriz
Benjumea4 , Alexandr L. Borisik5
1 Universidad Politécnica de Madrid, Spain
2 Institut of Geography, Russian Academy of Sciences, Russia
3 Institut of Industrial Research Akadempribor, Academy of Sciences of the Republic of Uzbekistan,

Uzbekistan
4 Instituto Geológico y Minero de España-CSIC, Spain
5 Arctic and Antarctic Research Institute (AARI), St. Petersburg, Russia

The polythermal glaciers of Svalbard are expected to undergo changes in its hydrothermal structure as a consequence of current climate change. Ground-penetrating radar(GPR) has been shown to be an effective tool to infer the hydrothermal structure of polythermal glaciers. Despite extensive radar campaigns in Svalbard, the eastern coast ofcentral Spitsbergen has been devoid of GPR surveys until very recently. In spring 2014 wecarried out extensive radar measurements on Elfenbeinbreen and Sveigbreen, in Sabine
Land, close to the eastern coast of central Spitsbergen. The GPR profiling, using a radarwith central frequency of 25MHz, covered a total length of 105 km on Elfenbeinbreen, and
36 km on Sveigbreen. Average ice thickness were 85 ± 9 m (Elfenbeinbreen) and 74 ± 7
m (Sveigbreen), while maximum thickness were 285 ± 7 and 212 ± 5 m, respectively. The
relative thickness of the cold ice layer was larger than that usually found by the authors
for glaciers of similar size in central and western Nordenskiöld Land and in Wedel Jarlsberg
Land. The thickness of the upper cold-ice layer of Elfenbeinbreen varies between roughly
80 and 250 m, though generally is about 120-150 m thick. By contrast, the thicknessof the cold layer of Sveigbreen is much thinner, typically 60-80 m. In Spring 2022 werepeated nearly the same GPR profiles for Sveigbreen, using the same radar equipment.
This allowed us to compare both the total ice thickness changes and the changes in thickness of the cold and temperate ice layers. Our preliminary results suggest a decrease in
the total ice thickness of the same order as the decrease in the thickness of the temperate ice layer (both in the order of 2-3 m a−1 ), with the cold ice layer showing little change
in thickness. This contrasts with the results obtained by the authors and colleagues inwestern Nordenskiöld Land glaciers such as Fridtjovbreen and Erdmanbreen, where thecold ice layer thickness increased, at rates of ca. 1.6 m a−1 for the upper western basinof the Fridtjovbreen, while its temperate ice layer experienced thinning rates similar to
those found in Sveigbreen for a similar period.

Reconstructing the past two surges of Fisher Glacier,
Yukon
Gabriel Partington1 , Luke Copland1 , Dorota Medrzycka1 , William Kochtitzky2 , Benoît
Lauzon1
1 University of Ottawa, Canada
2 University of New England, USA

Fisher Glacier is a large surge-type glacier located in the southeastern portion of the St
Elias Icefield in Kluane National Park, Yukon. While several previous studies have focusedon the surge behavior of other glaciers in the vicinity, Fisher’s surge history and behavior
has yet to be investigated in detail. An analysis of ice surface velocities, surface elevation
changes, and changes in terminus extent, derived from satellite imagery and historical air
photos, have allowed for the identification of two surges over the past 70 years. The oldest documented surge initiated in the late 1960s or early 1970s, which was marked by asignificant terminus advance and an increase in terminus area, as well as the appearanceof large crevasses extending upglacier into the upper ablation area. This period of active
surging was followed by a quiescent phase of >40 years, significantly longer than the 1020 year quiescent phase typical of other glaciers in this area, such as Lowell and Donjek.
The glacier entered a new active phase between early 2015 and late 2016. This second
surge was characterized by a terminus advance of nearly 2 km in some water-terminatingareas, an increase in velocities in the lower ablation zone from approximately 100 m yr−1
during the quiescent phase to about 1700 m yr−1 in late 2015, when the surge seems
to have peaked, and a rapid displacement of surface features (e.g., supraglacial lakes
and looped moraines) in the ablation zone. In late 2016, ice surface velocities dropped
from 1400 m yr−1 to 50 m yr−1 in a span of 2-3 months. Since then, the terminus hasremained largely unchanged, although the crevasses that formed during the surge havelargely disappeared as the ice surface has slowed during the present quiescent phase.

North Atlantic cooling and the impact on Icelandic glaciermass balanceGuðfinna Aðalgeirsdóttir1 , Brice Noel2 , Finnur Pálsson1 , Steingrímur Jónsson3
1 University of Iceland, Iceland
2 University of Liège, Belgium
3 University Centre of the Westfjords, Iceland

MISSING

Greenland slush limits; comparing remote sensing and
RCM simulations
Horst Machguth1 , Andrew Tedstone1
1 Department of Geoscience, University of Fribourg, Switzerland

Streams and lakes develop each summer over the marginal regions of the Greenland
ice sheet. These hydrological systems reach well into the accumulation area and indicatethat surface runoff of meltwater is an important component of the mass balance of theGreenland ice sheet. Here we map daily slush limits, a proxy for the extent of surface
runoff, using daily MODIS data (500 m spatial resolution). Our automated algorithm relies,
among other parameters, on spatial variability of surface albedo. The algorithm is applied
to all of Greenland for the years 2000 to 2021. Albeit MODIS’ spatial resolution is toocoarse to resolve streams or lakes, the results highly agree to surface runoff mappingfrom higher resolution satellite imagery. The data document significant increasing trends
in slush limits until the year 2012, but not thereafter. The slush limit typically rises quickly
early in the melt season, but upward migration halts before melting ceases. We utilize
the high spatial and temporal resolution of the data as a means of validation of stateof-the-art regional climate models (RCMs). The comparison of MODIS daily slush limits
and RCM runoff limits indicates that the RCMs overestimate runoff area. This observationis also confirmed by auxiliary satellite and field data. Validating RCMs using slush limit
elevations has the potential to further improve regional climate models and our estimatesof Greenland’s contribution to sea level rise. However, we also show that the comparison
is challenged by the very different characteristics of “modelled” and “real-world” runoff.

Reconnaissance of Alfred Wegener’s West Greenland
Expedition: bridging a century of climate change work:
1929 to 2022
Jakob Abermann1 , Baptiste Vandecrux2 , Sebastian Scher3 , Florina Schalamon1 , Andreas
Trügler1,3 , Robert Fausto2 , Wolfgang Schöner1
1 Graz University, Austria
2 GEUS, Denmark
3 Know-Center, Austria

The cryosphere in Greenland is currently undergoing strong changes. While remotesensing improves our understanding of spatial and temporal changes across scales forrecent decades, particularly our knowledge during the pre-satellite era is scarce and thus
valuable in a climate change perspective. At Graz University, the last work-place of Alfred
Wegener, we have access to the extensive expedition results from their epic 1929-1931
expedition to Greenland. This coincides with a particularly warm phase particularly in
the Arctic. Local conditions at the Qaamarujup glacier have changed dramatically sincethen with a length reduction of more than 2 km, a rise in terminus position and thickness
reduction by several hundreds of meters. During a reconnaissance expedition in summer
2022 we installed autonomous weather and ablation stations at the same locations as
Wegener did in the 1930s, based on their excellent documentation. In order to connect
the ablation rates at the changed surface conditions over the course of a century, we performed innovative UAV-based atmospheric measurements. In addition to the in-situ work,
we challenge reanalysis products with high-quality ground-truthing from the pre-satelliteera. Applying machine learning algorithms, we assess the potential for using historicalmeteorological and glaciological data together with reanalysis products and contemporary measurements in order to determine long-term geometrical feedback processes.

Vertical ice - morphology of the terrestrial ice margin
in Greenland
Jakob Steiner1 , Jakob Abermann1 , Rainer Prinz1
1 Graz University, Austria

The terrestrial ice margin of the Greenland ice sheet and its ice caps vastly exceeds
the relative fraction of the total ice margin made up by ocean terminating glaciers. Whileof course of relatively minor importance in the total ice flux it provides meltwater to terrestrial ecosystems along the ice sheet. It also provides a unique opportunity to study thehistory of the ice sheet through the visible layers emerging and its dynamics could potentially tell us something about the sensitivity of the ice sheet to regional climatic change.
Exploiting the high resolution ArcticDEM and relying on insights from field studies at thenorthernmost ice margin, we present an analysis of the geomorphology of the terrestrial
ice margin. Comparing the dataset to ice velocity and mass balance products allows firstanswers to the question why the margin oscillates between ramp like structures of very
shallow angles and steep vertical sections. We hypothesize that the margin morphology
is primarily linked to ice dynamics but that the perseverance of vertical sections is also
linked to the peculiar energy fluxes at play in this setting. The dataset will allow us to upscale insights from field investigations of ice dynamics and energy fluxes to the regional
scale.

Trends in Greenland ice sheet observational records:
implications for changing ice volume
Jason Box1 , Baptiste Vandecrux1 , Andreas P. Ahlstrøm1 , Nanna B. Karlsson1 , Adrien
Wehrlé2
1 GEUS, Denmark
2 University of Zurich, Switzerland

This work examines trends in Greenland ice sheet air temperature, snow accumulationand snowline elevation. Air temperature records are from Swiss Camp and other GC-Net
sites, extended as far back in time as 1987 in the case of Summit using U Wisconsin
data. The scientific question is what physical processes are behind observed trends.
Snow accumulation data are from snow/firn cores, supplemented by recent snow profiles
obtained by GEUS. The scientific question is what sites contain statistically significant
accumulation trends and what records correlate with regional air temperatures. Ice sheetsnowline is retrieved from MODIS and Sentinel-3. The snowline variations are mapped
regionally and examined for trends in context of changing equilibrium line altitude and theimplied ice area and volume changes to reach dynamic equilibrium with recent climate.

Glacier recession vs. water drainage at a forefield (Werenskioldbreen, Svalbard)
Katarzyna Stachniak1 , Krzysztof Janik1 , Dariusz Ignatiuk1 , Jacek Jania1 , Elżbieta Łepkowska1
1 Univeristy of Silesia in Katowice, Poland

The consequence of climate change in the Arctic are observing reducing volume andretreat of the glaciers. This results in the expansion of the forefield, thereby increasing its
role in the hydrology of glacierised catchment for water cycle. Due to permafrost loss anddeeper water infiltration possibility, the forefield sub-surface partis also becoming more
important for the entire hydrology balance in the catchment area. Therefore, we aimed toanswer the following question: To what extent does the enlarging glacier’s forefield affectthe catchment’s proglacial drainage system and water balance, groundwater flow, andstorage capacities? We conducted hydrological research at the Werenkioldbreen catchment in Svalbard. We used the modelling approach to enable both quantitative and spatial analyses, with particular attention to the glacier’s forefield role in drainage and water
storage, by studying two components: (1) the surface part of the forefield: a hydrologicalbalance and surface drainage, (2) the sub-surface part of the forefield: a hydrogeologicalbalance, groundwater drainage, and storage. We implement a combination of two modelling tools: hydrological model (SWAT) and-hydrogeological model (FEFLOW) enable toobtain a complete overview of the water cycle in the Werenskioldbren glacier’s forefield
The models are powered by glacier ablation waters data that based on the glaciologicalablation model (temperature-index model) and liquid precipitation amount. The modellingstudies for hydrological and hydrogeological processes allowed us to synthesise ongoing
research and long-term monitoring in the Werenskioldbreen catchment.

Present changes of Jostedalsbreen, Norway’s largest
ice cap
Liss Marie Andreassen1 , Mette Gillespie2 , Kjetil Melvold1 , Kamilla Sjursen2 , Benjamin
Robson3 , Hallgeir Elvehøy1 , Bjarne Kjøllmoen1 , Jacob Yde2
1 Norwegian Water Resources and Energy Directorate (NVE), Norway
2 Western Norway University of Applied Science, Norway
3 University of Bergen, Norway

The objective of the JOSTICE project is to assess the present and future changes inmass balance, runoff, ice volume and local climate of Jostedalsbreen, and determine thesocietal impact of these changes on hydropower production, tourism and agriculture. The
Jostedalsbreen ice cap is mainland Norway’s and Europe’s largest ice cap accounting for
20 % (458 km2 in 2019) of the total glacier area of mainland Norway. It has been divided
into more than 80 units and has several distinct glacier outlets. Here we present changesof Jostedalsbreen based on repeated map surveys and glacier inventories from 1966 and2020. We also present recent ice thickness surveys and glaciological measurements revealing the present state of the ice cap.

Terminus area changes of all Northern Hemisphere marineterminating glaciers since 2000
Luke Copland1 , Will Kochtitzky2
1 University of Ottawa, Canada
2 University of New England, USA

To map and better understand the recent changes of marine-terminating glaciers,
we used satellite imagery to manually digitize the terminus position of all glaciers thatreached the ocean in the Northern Hemisphere in 2000, 2010, and 2020. A total of1704 glaciers terminated in the ocean in 2000, with 123 of these ceasing to reach theocean by 2020. Overall, 85% of glaciers retreated and only 2.5% advanced, while theremaining glacier termini didn’t change outside of uncertainty limits. Most of the area
losses occurred in Greenland, which experienced 62% of total hemispheric area loss. To
understand what causes variations in the rate of retreat we examined a range of environmental and other variables. There was no significant correlation between retreat rates
and changes in air temperature, ocean temperature, or sea ice over any time period. Instead, we found that most retreat occurred on glacier termini with ice shelves, reverse
bed slopes, particularly wide calving margins, or are surge-type. Of the few glaciers that
advanced, most of them are surge type. In all, northern hemisphere glaciers lost 7527.3± 30.7 km2 (389.7 ± 1.6 km2 a−1 ) from 2000 to 2020, or an average of just over 1 km2
per day.

Factors controlling terminus position of tidewater glaciersin Hornsund fjord (Svalbard)
Małgorzata Błaszczyk1 , Mateusz Moskalik2 , Mariusz Grabiec1 , Jacek Jania1 , Waldemar
Walczowski3 , Tomasz Wawrzyniak2 , W. Tad Pfeffer4
1 University of Silesia in Katowice, Poland
2 Institute of Geophysics, Polish Academy of Sciences, Warszawa, Poland
3 Institute of Oceanology, Polish Academy of Sciences, Sopot, Poland
4 Institute of Arctic and Alpine Research and Department of Civil, Environmental, and ArchitecturalEngineering, University of Colorado at Boulder, Boulder, USA

In this study, we investigate seasonal and decadal changes in the terminus positions ofeight tidewater glaciers in Hornsund, the southernmost fjord of the Svalbard Archipelago.
To observe termini fluctuations we applied multispectral and radar satellite data from1992 to 2020. We found that the long-term retreat of glaciers was interrupted by small
advances or surges. Further, seasonal changes in termini position were compared tobasic meteorological data (air temperature, positive degree day index, and liquid precipitation), sea surface temperature, the mean temperature in the bays at the glacier front,
fast sea ice coverage, and bathymetry at the glacier front. Overall, we found regional
synchrony in glaciers’ fluctuations and agreement between terminus advance/retreat andchanges in air and sea temperature. Seasonal terminus position fluctuations for the majority of glaciers are sensitive to glacial runoff and related discharge-driven submarine
melt and calving. The fastest retreat occurred in the warm years, with relatively highair and sea temperatures. In colder years glaciers slowed their retreat or advanced periodically. Additionally, we present five-year series (2016-2020) of detailed seasonal andannual variations in front positions, ice flux, and frontal ablation, to evaluate processes
responsible for changes in termini positions. The contribution of annual ice flux to retreat rate varied from year to year, but showed similarities among the glaciers. Results
indicate that changing contribution of individual components affecting the front position(glacier velocity v. frontal ablation) is mainly controlled by air and sea temperature, whilewater depth at the front plays a secondary role. We also found that the duration of theretreat and advance periods are strongly correlated with the sea temperature in the fjord.
Results indicate that the expected increase in air temperature and water temperature of
the West Spitsbergen Current will have further implications for glacier velocity and frontal
ablation.

Hypsometric control on basin sensitivity under risingequilibrium line altitudes in the Northern Canadian Arctic Archipelago
Madeline Myers1 , Laura Thomson1
1 Queen’s University, Canada

Glacier melt production and flux to the Arctic Ocean is important to global thermohaline circulation and local ecosystem dynamics. We present hydrologically-correctedglacier outlines from the Randolph Glacier Inventory and hypsometries derived from the
32m ArcticDEM product. Watersheds are derived from the DEM such that all liquid water
would eventually flow to the ocean. We group over 2000 watersheds into 12 basins according to ocean basin or channel and surface water circulation pathways. Within eachbasin, the equilibrium line altitude (ELA) is increased from the current 60-year average
to show the distribution of total melt potential across the NCAA. Accumulation area ratio(AAR) and ablation area are treated as proxies for glacier mass budget sensitivity to rising ELAs. Broadly, the degree of ELA change across the region is unknown. We therefore
impose different magnitudes of change to simulate the variability of AARs and ablation
areas across NCAA basins. We find a latitudinal trend of ELA position relative to glacierbulk area. For southerly glaciers where the ELA is above the glacier bulk area, sensitivity
decreases as the ELA rises. For northerly glaciers where the ELA is below the glacier bulk
area, the sensitivity first increases with ELA until a 500 – 600 m ELA rise as the ELA surpasses the glacier bulk area elevation. However, under a regional mean ELA rise of only
200 m as measured by ablation area and ∼300 m for the AAR, northerly glaciers’ sensitivity surpasses that of southerly glaciers. Both values are near the standard deviation ofa representative glacier, the White Glacier, ELA for the past 60 years (243 m).

Greenland ice sheet surface water vapour fluxes fromautomatic weather station records
Maiken Kristiansen Revheim1 , Jason Box1 , Baptiste Vandecrux1 , Christine Hvidberg2
1 Geological Survey of Denmark and Greenland, Denmark; Niels Bohr Institute, Copenhagen Uni-

versity, Denmark
2 Niels Bohr Institute, Copenhagen University, Denmark

The mass balance of the Greenland ice sheet is influenced by surface water vapour
fluxes. Sublimation and evaporation remove mass from the surface, while condensationand frost deposition adds mass. The energy spent on sublimation and evaporation cools
the surface and thus reduces melting, whereas frost deposition and condensation will
have the opposite effect. Box and Steffen (2001) estimated the net surface water vapour
flux of the ice sheet using data from the Greenland Climate Network (GC-Net) automaticweather station (AWS) from 1995 to 2000. In the last 22 years, the Arctic has been
warming at an increasing rate. This project aims to extend the work of Box and Steffen(2001) to the GC-Net AWS data up to 2022 and to investigate how the water vapour fluxes
are influenced by arctic warming. The determination of instrument height is crucial for
estimating water vapour fluxes but is complicated by the accumulation of new snow at
the surface and by the AWS mast being raised periodically to keep the sensors from being
buried. Here, we use field notes, photogrammetry and surface height change measuredby acoustic sounders to reconstruct the instrument heights. For the time periods with twoworking levels of temperature, humidity, and wind speed data, we will estimate the net
water vapour fluxes and compare with regional climate models.
Work Cited - Box, J. E. and Steffen, K.: Sublimation on the Greenland Ice Sheet fromautomated weather station observations, J. Geophys. Res., 106, 33965–33981,
https://doi.org/10.1029/2001jd900219, 2001.

The control of short-term ice mélange weakening episodes
on calving activity at major Greenland outlet glaciersMartin Lüthi1 , Adrien Wehrlé1
1 Institute of Geography, University of Zurich, Switzerland

The dense mixture of iceberg of various sizes and sea ice observed in many of Greenland’s fjords, called ice mélange (sikussak in Greenlandic), has been shown to have asignificant impact on the stability of several Greenland tidewater glaciers mainly throughthe seasonal support it provides to the glacier terminus in winter. However, a clear understanding of shorter-term ice mélange dynamics is still lacking, mainly due to the highcomplexity and variability of the processes at play at the ice-ocean boundary. In thisstudy, we use a combination of Sentinel-1 radar and Sentinel-2 optical satellite imagery
to investigate in details intraseasonal ice mélange dynamics and its link to calving activity
at three major outlet glaciers: Kangerdlugssuaq Glacier, Helheim Glacier and Sermeq Kujalleq in Kangia (Jakobshavn Isbrae). In those fjords, we identified recurrent ice mélange
weakening (IMW) episodes consisting in the up-fjord propagation of a discontinuity between jam-packed and weaker ice mélange towards the glacier terminus. At a late stage,i.e. when the IMW front is in the vicinity of the glacier terminus, these episodes were
often correlated with the occurrence of large-scale calving events. The IMW process isparticularly well visible at the front of Kangerdlugssuaq glacier and presents a cyclic behavior, such that we further analyzed IMW dynamics during the June-November period
from 2018 to 2021 at this location. Throughout this period, we detected 30 IMW episodes
with a recurrence time of 24 days, propagating over a median distance of 5.9 km andfor 17 days, resulting in a median propagation speed of 400 m/d. We found that 87%of the IMW episodes occurred prior to a calving event visible in spaceborne observations
and that 75% of all detected calving events were preceded by an IMW episode. These
results therefore present the IMW process as a clear control on the calving activity ofKangerdlugssuaq glacier. Finally, using a simple numerical model for ice mélange motion,
we showed that a slightly biased random motion of ice floes without fluctuating external
forcing can reproduce IMW events and its cyclic influence, and explain observed propagation speeds. These results further support observations in characterizing the IMW process
as self-sustained through the existence of an IMW-calving feedback. This study therefore
highlights the importance of short-term ice mélange dynamics in the longer-term evolution of Greenland outlet glaciers.

Some thoughts and observations on basal motion beneath the (still) polythermal McCall Glacier, Alaska
Matt Nolan1
1 Serving Earth Science Inc., USA

Over the past 65 years, each research team on McCall Glacier has added to our collective knowledge of its polythermal nature. Ice in the accumulation area is temperate
throughout its depth due latent heat released by refreezing of meltwater in firn and alarge portion of the ablation area is also temperate at its base due to both advection
and geothermal heat flux when the glacier was much larger. Our measurements over the
past 20 years show that every location of this glacier experiences a summer speedup
and modeling shows that significant basal motion must also be occurring in winter within
the temperate zone of the ablation area. The prediction made in 2010 by our thermomechanical flow modeling was that as the glacier thins and cools, the basal ice can nolonger remain temperate within the sliding area, responding on a time-scale of 100 years
after thinning starts in earnest. The ELA began retreating in the late 1800s and this rate
began increasing steadily from the 1950s onwards, now often above the top of the glacierand thus eliminating the porous firn area which kept the upper glacier warm. It seems
clear that thinning has caused slight decreases in speed throughout the glacier over the
past 20 years but that by far the biggest decreases in speed are occurring in the area webelieve to be sliding in winter. This decreasing trend started somewhat abruptly 2008
and speeds here have now dropped more than a third – could we have witnessed the
beginning of the end of winter sliding on McCall Glacier? Part of our current research is
aimed at determining when global warming will turn this polythermal glacier into a cold
one and how this will affect its rate of demise under various climate scenarios.

Impact and evaluation of improved ice surface roughness formulation in RACMO 2.3p2 on Greenland surface
melt modelling
Maurice Van Tiggelen1 , Paul Smeets1 , Carleen Reijmer1 , Christiaan van Dalum1 , BriceNoël1 , Willem Jan van de Berg1 , Dirk van As2 , Jason Box2 , Robert Fausto2 , Michiel van den
Broeke1
1 IMAU, Utrecht University, The Netherlands
2 GEUS, Denmark

Over the Greenland ice sheet, the sensible heat flux (SHF) is a major source of energy
for surface melt, especially in the low-lying ablation area where both large temperature
gradients, persistent katabatic winds and variable ice surface roughness coexist. Currently, regionals climate models such as RACMO2.3p2 use a constant value for ice andsnow surface roughness. Since the surface roughness is highly variable in space andtime, this assumption results in a poorly constrained uncertainty for modelled surface
melt.
It this study we implement a variable aerodynamic roughness length (z0m) parameterization for bare ice in RACMO 2.3p2, and we perform different sensitivity experimentsthat vary the z0m model settings. We also test different formulations for the roughness
length for heat (z0h) based on in situ eddy covariance observations. We compare theresults to both IMAU and PROMICE weather station observations and find that the SHF
is systematically underestimated by on average 15 Wm−2 (44%), during summer below
1000m elevation. This partly explains the average underestimation of modelled surface
melt of 24 Wm−2 (22%). While using a more realistic value for z0m only marginally improves the SHF in RACMO2.3p2, we find that the SHF is highly sensitive to the value ofthe z0h parameter. We conclude an accurate estimate of modelled SHF, and subsequentsurface melt, requires realistic values for both the z0m and z0h parameters, especially tocapture extreme Greenland melt events.

Modelling lateral meltwater flow atop the Greenland
Ice Sheet’s near-surface ice slabs
Nicole Clerx1 , Horst Machguth1
1 University of Fribourg, Switzerland

The Greenland ice sheet is losing mass. Thereby, the location of the runoff limit, thehighest elevation from which meltwater finds its way off the ice sheet, plays an importantrole. Above the runoff limit all meltwater refreezes and does not contribute to mass loss.
In recent years surface runoff has increasingly occurred from higher elevations, thereby
expanding the area of mass loss: between 1985 and 2020, the maximum runoff limit roseby on average 194 metres, expanding the visible runoff area by around 29
The observed rise in the runoff limit might be related to intensive meltwater refreezing
within the firn which leads to the formation of thick ice layers, also called ice slabs. Our
field experiments, carried out at around 1750 m a.s.l. on the K-Transect, have shown that
meltwater generated over ice slabs is generally forced to flow laterally: initially through anear-surface slush matrix and then forming streams and rivers. It remains unclear, however, how much of the meltwater contributes to runoff, and which percentage refreezes
and contributes to ice slab formation or expansion.
Here we present a conceptual quasi 2D-model of runoff, that simulates lateral meltwater flow on top of an ice slab using firn hydrological properties measured on the southwest
Greenland ice sheet. We adapted a gridded linear-reservoir runoff routing model to calculate (i) the distance meltwater can travel within one melt season, and (ii) when meltwater
breakthrough at the snow surface (i.e. slush formation) occurs. First results provide insight into the evolution of the water table height over time that matches observations
made during our summer field campaign. We are exploring ways to incorporate meltwater refreezing, to better understand ice slab evolution and their impact on the fate of
meltwater between vertical percolation, refreezing and lateral runoff.

Crystal fabric orientation of the NEGIS ice stream
Olaf Eisen1 , Tamara Annina Gerber2 , David Lilien3 , Nicholas Rathmann2 , Steven Franke1,2 ,Tun Jan Young4 , Fernando Valero-Delgado1 , Reza Ershadi5 , Reinhard Drews5 , Ole Zeising1 ,Angelika Humbert1 , Nicolas Stoll1 , Ilka Weikusat1 , Aslak Grinsted2 , Christine Hvidberg2 ,Daniela Jansen1 , Heinrich Miller1 , Veit Helm1 , Daniel Steinhage1 , Charles O’Neill6 , John
Paden7 , Prasad Gogineni6 , Dorthe Dahl-Jensen2,3
1 Alfred Wegener Institute, Bremerhaven, Germany
2 The Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
3 Centre for Earth Observation Science, University of Manitoba, Winnipeg, Canada
4 Scott Polar Research Institute, University of Cambridge, Cambridge, United Kingdom
5 Department of Geosciences, Tübingen University, Tübingen, Germany
6 Remote Sensing Centre, University of Alabama, Tuscaloosa, USA
7 Centre for Remote Sensing of Ice Sheets (CReSIS), University of Kansas, Lawrence, USA

Anisotropic crystal fabrics in ice sheets develop as a consequence of deformation andhence record information of past ice flow. Simultaneously, the fabric affects the presentday bulk mechanical properties of glacier ice because the susceptibility of ice crystals to
deformation is highly anisotropic. This is particularly relevant in dynamic areas such as
fast-flowing glaciers and ice streams, where the formation of strong fabrics might play acritical role in facilitating ice flow. Anisotropy is ignored in most state-of-the-art ice sheet
models, and while its importance has long been recognized, accounting for fabric evolution and its impact on the ice viscosity has only recently become feasible. Both theapplication of such models to ice streams and their verification through in-situ observations are still rare. Ice cores provide direct and detailed information on the crystal fabric,but the logistical cost, technical challenges, particularly in fast-flowing ice and shear margins, difficulty in reconstructing the absolute orientation of the core and their limitationof being a point measurement make ice cores impractical for a spatially extensive evaluation of the fabric type. Indirect geophysical methods applied from or above the ice
surface create the link between the small scale of laboratory experiments and ice–core
observations to the large-scale coverage required for ice flow models and the complete
understanding of ice stream dynamics. Here, we present a comprehensive analysis of the
distribution of the ice fabric in the upstream part of the North-East Greenland Ice Stream(NEGIS). Our results are based on a combination of methods applied to extensive airborne
and ground-based radar surveys, ice- and firn-core observations, and numerical ice-flow
modelling. They show that in the onset region of NEGIS and around the EGRIP ice coredrilling site, the fabric is strongly anisotropic, forming a horizontal girdle perpendicular to
the ice flow, while anisotropy reduces quickly over distances of less than five ice thicknesses outside of the ice stream’s shear margins. Downstream of the drill site, the fabricdevelops into a more vertically symmetric and almost isotropic configuration on a timescale of around 2 ka, the first in-situ observation of this kind. Our study shows how icecore based fabric observations, geophysical surveys and ice-flow modelling complement
each other to obtain a full spatial view of the spatially strongly varying fabric.

Changes in Glacial Hydrology in Response to Recent Increases in Surface Melt on Ellesmere Island, CanadianHigh Arctic
Penelope Gervais1 , Luke Copland1
1 University of Ottawa, Canada

Glacier mass losses, resulting from enhanced surface melt, have more than doubled
since the late 1990s in the Canadian Arctic Archipelago (CAA). However, little is currently
known as to whether this had an influence on the size or extent of supraglacial hydrological networks. Some studies have mapped these networks and their connection to
ice dynamics in the CAA for single points in time, but no previous research has investigated their temporal evolution or variability. In this study we are therefore assessing
temporal and spatial changes of the supraglacial hydrology across the 800 km latitudinal gradient of Ellesmere Island. Various semi-automated methodological frameworks
for mapping supraglacial hydrological features are being evaluated, using recent opticalsatellite imagery of varying spatial resolutions like Planet, Sentinel-2 and Landsat-8. Suchmethodologies generally rely on the calculation of the normalized difference water index
to enhance spectral contrast for linear feature enhancement, and are occasionally accompanied by a digital terrain model to identify potential flow routes. Future work will extend
these methodologies to map the surface hydrology of glaciers across Ellesmere Island
since the 1980s by making comparison with historical ASTER, SPOT and Landsat satellite
imagery, and potentially to the 1950s by making comparison with historical air photos.
Preliminary results indicate that there have been significant changes in the number andsize of supraglacial streams over the past 40 years, with an acceleration in the rate ofchange over the last decade. Many perennial streams have become wider as well as moresinuous and incised, with greater relative changes in incision in far northern areas. Wellestablished streams have also extended up glacier as accumulation zones shift to higher

elevations, increasing overall drainage density especially when paired with the observed
increase in channel frequency across Ellesmere Island.

Mass loss of Qaanaaq Ice Cap in northwestern Greenland from 2012 to 2022
Shin Sugiyama1 , Kaho Watanabe1 , Ken Kondo1
1 Hokkaido University, Japan

Since 2012, we have conducted surface mass balance measurements on Qaanaaq
Glacier, an outlet glacier of Qaanaaq Ice Cap in northwestern Greenland. Annual surface mass balance was measured by using poles installed at six locations distributed at
243–968 m a.s.l. Mean specific mass balance over the entire ice cap was computed foreach year, by assuming that surface mass balance is a function of elevation. Glaciersurface elevation was measured along the central flowline by kinematic GPS surveys in
July–August 2012, 2019 and 2022. The mean specific mass balance from 2012 to 2022
was 0.20 m w.e. a−1 at 968 m a.s.l. and ?1.68 m w.e. a−1 at 243 m a.s.l. Significant
interannual variations of ∼2 m w.e. a−1 were observed at each site. The cumulative massbalance of the ice cap from 2012 to 2021 was -4.02 ± 0.22 m w.e. Mass balance wasmost negative in 2014/15 (-1.08 ± 0.04 m w.e. a−1 ), which we attribute to relatively highsummer temperature and a small amount of snow accumulation. The glacier surface elevation dropped from 2012 to 2022, with a rate greater in 2019–2022 (-0.89 m a−1 ) thanin the earlier period of 2012–2019 (-0.70 m a−1 ). The magnitude of the rate increased in
the later period particularly in the middle of the ablation zone, whereas the change wassmaller in the regions near the equilibrium altitude and near the terminus. Our results
imply that glaciers and ice caps in the Qaanaaq region are rapidly losing mass over thelast decade at a rate varying from year to year. A warming climate is the most importantdriver of the mass loss, but changes in snow accumulation play a key role as well.

Frontal ablation modulated by hydropower regulation?
A case study from Austdalsbreen, Western Norway
Thorben Dunse1 , Hallgeir Elvehøy2 , Even Loe3 , Gernot Seier4 , Jakob Aberman4 , Mette
Kusk Gillespie1 , Jacob Yde1
1 Western Norway University of Applied Sciences (HVL)
2 NVE, Norway
3 Statkraft, Norway
4 University of Graz, Austria

Austdalsbreen is a lake-terminating outlet glacier of the Jostedalsbreen Ice Cap inWestern Norway. Construction of a dam in 1986, has led to water-level variations due
to hydropower regulation of Styggevatn reservoir. The Norwegian Water Resources andEnergy Directorate (NVE) has been monitoring the mass balance of Austdalsbreen since1988. This includes measurements of surface mass balance from a network of mass balance stakes, as well as the annual assessment of frontal ablation. Since 1987, the calving
front has retreated by about 720 m.

Here we present a 1-year record of time-lapse photography capturing the calving front,
the ablation area and the lake four times a day, from September 2021 to September 2022.
Simultaneous measurements of surface air temperature and water-level in the reservoir
allow us to study the potential role of weather conditions and hydropower regulation inmodulating seasonal variations in glacier dynamics and frontal ablation. Recent calving
activity was highest in a central section of the calving front, which is reflected in dynamic
thinning and a negative geodetic mass balance within this region.

Glacier geometry and mass change at Sirmilik and Auyuittuq National Parks, Nunavut, Arctic Canada, 1960-2020
Wai Yin Cheung1
1 Queen’s University, Canada

The Canadian Arctic Archipelago hosts one-fifth of the global glacierized terrain (excluding the ice sheets). Under the most rapid Arctic warming scenario, this region has
become the third-largest contributor to global mean sea-level rise. However, knowledgeof spatial variability of glacier response and associated sea-level rise contributions inthis region is still relatively uncertain. Although the highest density of long-term (>50yrs.) records of glacier surface mass balance in the Arctic is from the Canadian Arctic
Archipelago, most data is located above a latitude of 74 degrees. Yet, long-term measurements of glaciers’ spatial distribution of ice thickness and volume on the Baffin & Bylot
Islands are still largely absent. As such, the regional impact of the glacial changes andthe associated geohazards, such as meltwater flooding, still experience significant knowledge gaps. In response to these significant research gaps, this PhD project attempts to
expand temporal and spatial coverage of glacier monitoring on the Baffin & Bylot Islands
by in-situ, photogrammetrical and remote sensing approaches. This comprehensive studyof Baffin & Bylot Islands glacier systems offers a better understanding of regional glacierfluctuations to predict the future dynamics of Canada’s northern landscapes. It will furthermore support analysis of the spatial and morphological characteristics of particularly
sensitive glaciers. Additionally, the threats related to glaciated terrains are usually characterised by the involvement of surface or subsurface ice, which are highly sensitive toclimatic changes. To mitigate the glacier-related environmental, socioeconomic and cultural impact under future wetter and warmer Arctic, those findings of ice volume and areal
extent change will help to identify the potential natural hazards associated with the glacial
environments. Coupled with local Inuit glaciological knowledge, the outcome of a regional
detailed hazard assessment will provide valuable information for the local communities,
Parks Canada management and the National Park visitors. These project findings will
also contribute to new geodetic mass balance estimation for the World Glacier Monitoring
Service (WGMS) and promote the establishment of a new benchmark program. PS: Preliminary finding will be presented as this project is still in the initial stage.

A novel large-scale ice thickness inversion method tested
on Kronebreen, Svalbard
Thomas Frank1 , Ward van Pelt1
1 Uppsala University, Sweden

Subglacial topography plays a crucial role in determining the future evolution of glaciers.
Although recent progress has been made in producing large scale products of ice thickness, substantial uncertainties for individual glaciers still exist. Here, we present a fast
thickness inversion approach that is capable of using advanced physics of state-of-the-art
ice flow models to produce maps of subglacial topography that are consistent with external forcing and ice dynamics. We harness the vast amount of available observations,such as surface elevation change and ice velocity, to constrain both bed elevation andsubglacial friction. This allows a seamless transition from bed recovery to prognostic simulations. Using the example of Kronebreen, a fast-flowing tidewater glacier on Svalbard,
and the ice-flow model PISM, we demonstrate that our approach is capable of dealing
with complex settings in a time-efficient manner. Ultimately, our method is of interestfor prognostic studies where bed topography needs to be constrained first, as well as forapplications on a larger scale.

The surge of high-Arctic Chapman Glacier, 1999-2018
Wesley Van Wychen1 , Hester Jiskoot2
1 University of Waterloo, Canada
2 University of Lethbridge, Canada

Surge-type glaciers have been identified throughout the Canadian Arctic but due tothe remoteness of the region and the limited availability of remote sensing data at highlatitudes, few surge behaviours been studied in detail. However, over the last decade,access to higher spatial and temporal resolution satellite data and derived products (i.e.
DEMs, displacement maps) has enabled the study of glacier surging at a level of detailthat allow a better process-based understanding of the mechanisms that underpin surging
in this region. In this study, we present a multi-decadal record (1999-2018) of annual surface flow velocities and quadrennial elevation changes for Chapman Glacier (81°N, 79°W),
Umingmak Nuna (Ellesmere Island), Nunavut. We also use historical satellite imagery toinvestigate the looped surface moraine patterns from 1975 to 2020 in order to place ourvelocity records within a longer temporal context. Our results indicate that the surge
phase of Chapman Glacier is at least 20-years long, with an increase in flow speed from∼25 to 200 m a−1 . The surge is spatially limited to the trunk and main tributary, each ofwhich experience differing periods of fast flow. The main surge front travels downglacierwith no detectable frontal advance and maximum thickening/thinning rates are of theorder of 10 m a−1 . Overall, these results provide more information about the variety ofsurge-type behaviours that occur in the Canadian Arctic and contribute to a growing bodyof literature characterizing the spectrum of dynamic flow instabilities in this region andworldwide.

Frontal ablation of Northern Hemisphere glaciers for
2000-2020
Will Kochtitzky1,2 , Luke Copland2 , Wesley Van Wychen2 , Romain Hugonnet3,4 , Regine
Hock5 , Julian A. Dowdeswell6 , Toby Benham6 , Tazio Strozzi7 , Andrey Glazovsky8 , Ivan
Lavrentiev8 , David Rounce9 , Romain Millan10 , Alison Cook2 , Abigail Dalton2 , Hester Jiskoot11 ,Jade Cooley11 , Jacek Jania12 , Francisco Navarro13
1 School of Marine and Environmental Programs, University of New England, Biddeford, Maine, USA
2 Department of Geography, Environment and Geomatics, University of Ottawa, Ottawa, Ontario

K1N 6N5, Canada
3 LEGOS, Université de Toulouse, CNES, CNRS, IRD, UPS, Toulouse, France, Laboratory of Hydraulics,
Hydrology and Glaciology (VAW)
4 ETH Zürich, Zürich, Switzerland, Swiss Federal Institute for Forest, Snow and Landscape Research(WSL), Birmensdorf, Switzerland
5 Department of Geosciences, University of Oslo, Oslo, Norway, Geophysical Institute, University of
Alaska Fairbanks, Fairbanks, USA
6 Scott Polar Research Institute, University of Cambridge, Cambridge, UK
7 Gamma Remote Sensing, Gümligen (BE), Switzerland
8 Institute of Geography, Russian Academy of Sciences, Moscow, Russia
9 Department of Civil and Environmental Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania, 15213, USA
10 Institut des Géosciences de l’Environnement, CNES, Grenoble, France
11 Department of Geography & Environment, University of Lethbridge, Lethbridge, Alberta, Canada
12 University of Silesia, Katowice, Poland
13 Universidad Politécnica de Madrid, Madrid, Spain

In the Northern Hemisphere, approximately one third of all mountain glaciers and ice
caps end in the ocean, but we have yet to quantify the contribution of iceberg calving, or
frontal ablation, to the mass loss of these glaciers in a consistent way. In this study weused a suite of satellite, field, and modeled datasets to quantify the frontal ablation of the1500 marine-terminating glaciers in the Northern Hemisphere, outside of the Greenland
Ice Sheet. This amounted to 44.47 ± 6.23 Gt a−1 from 2000 to 2010, and 51.98 ± 4.62
Gt a−1 from 2010 to 2020. We segregated the two terms of frontal ablation, discharge
and terminus volume loss, to understand their relative importance to inform how frontal
ablation may change in the future. Ice discharge accounted for 78 ± 13% of frontal ablation from 2000-2020, while the remainder was from terminus volume loss, which is moretransient and only comes from terminus retreat. The Russian Arctic accounted for 40%
of frontal ablation, more than any other region, with most of it coming from Franz Josef
Land. Svalbard and Alaska were the next two regions with the most frontal ablation at
16.82 ± 2.48 and 10.68 ± 0.33 Gt a−1 , respectively. These numbers are critically important for glacier mass balance estimates and models, as well as predicting the evolution of
glaciers in the coming decades. The data for each glacier is freely available through ourcorresponding publication in Nature Communications.

Supraglacial lake evolution on Tracy and Heilprin Glaciersin northwestern Greenland from 2014 to 2021
Yefan Wang1 , Shin Sugiyama1
1 Hokkaido University, Japan

Supraglacial lakes form during the melt season as meltwater collects within topographic depressions on the surface of glaciers and ice sheets. They affect the massbalance of glaciers and ice sheets in two ways: (1) enhance ice surface melt by lowing
the surface albedo, (2) accelerate the ice flow by delivering a large amount of meltwater
into the subglacial environment during lake-drainage events and reducing basal friction.
Therefore, studying the evolution of supraglacial lakes helps us further understand theeffect of meltwater on glaciers and ice sheets. With this background, we analyzed satellite images acquired between 2014 and 2021 to investigate the evolution of lakes on twolarge marine-terminating glaciers in northwestern Greenland. To generate a high spatiotemporal resolution record of the lake area over Heilprin and Tracy Glaciers, we applieda machine learning method on two medium-resolution optical satellite datasets (Sentinel2 and Landsat 8) within Google Earth Engine. Although the basin areas of the two glaciers
are similar (654 km2 and 540 km2 ), the maximum lake extent on Heilprin Glacier (22.84km2) was approximately three times larger than that on Tracy Glacier (7.60 km2 ). The
lakes began forming in early June, which was followed by substantial expansion fromthe middle of June. After reaching a maximum thereafter, the lake area significantly decreased in August. The lake area peaked at different timing every year, depending on
meteorological conditions. In 2016, 2019, and 2020, the lake area reached a peak between late June and the beginning of July. In 2017 and 2018, however, the peaks wereobserved in late July because of relatively cold summer temperature. Regarding to theinter-annual variation, the maximum lake coverage during the study period was observedin 2019, whereas the lake extents were substantially smaller in 2017 and 2018. The lakearea was small in these two years because lakes were undeveloped in the region above
800 m a.s.l.