Climatic controls on interannual mass balance of Arctic glaciers and ice caps

Ma, Xiaojun; King, Matt; Bamber, Jonathan; Liu, Bin; Sun, Wenke; Wang, Qiuyu

doi:10.5194/egusphere-2026-3461

Preprints

https://doi.org/10.5194/egusphere-2026-3461

Preprints

08 Jul 2026

| 08 Jul 2026

Status: this preprint is open for discussion and under review for The Cryosphere (TC).

Climatic controls on interannual mass balance of Arctic glaciers and ice caps

Xiaojun Ma, Matt King, Jonathan Bamber, Bin Liu, Wenke Sun, and Qiuyu Wang

Abstract. Interannual variability in glacier and ice cap (GIC) mass balance can be large amplitude, masking the underlying decadal trends associated with external forcing. Here we apply Independent Component Analysis (ICA) to global GIC mass anomalies derived from the Gravity Recovery and Climate Experiment (GRACE) mission and GRACE Follow-On (GRACE-FO) satellite gravimetry missions over 2002–2024. We show that Arctic glacier regions dominate the leading interannual variability in the global gravimetry record, and account for more than two-thirds of recent global GIC mass loss. Two leading Arctic ICA modes explain ~75 % of interannual variance and are associated with North Atlantic Oscillation (NAO)- and Pacific Decadal Oscillation (PDO)-related multi-year climate variability. Multiple linear regression further shows that variability linked to these climate modes explains much of the interannual glacier-mass variability in Arctic glacier regions and significantly affects trend estimates. This effect is most pronounced in Alaska, where the uncorrected trend is about 25 % less negative than the value after accounting for this variability (−69 ± 21 Gt yr⁻¹ versus −92 ± 16 Gt yr⁻¹). These results suggest that persistent North Atlantic and Pacific circulation variability can substantially change regional glacier mass loss, with direct implications for interpreting recent Arctic glacier change and their secular trends driven by external forcing.

Received: 12 Jun 2026 – Discussion started: 08 Jul 2026

Publisher's note: Copernicus Publications remains neutral with regard to jurisdictional claims made in the text, published maps, institutional affiliations, or any other geographical representation in this paper. While Copernicus Publications makes every effort to include appropriate place names, the final responsibility lies with the authors. Views expressed in the text are those of the authors and do not necessarily reflect the views of the publisher.

Download & links

Preprint (PDF, 1076 KB)

Supplement (43725 KB)

Download & links

Preprint (1076 KB)
Metadata XML
Supplement (43725 KB)
BibTeX
EndNote

Xiaojun Ma, Matt King, Jonathan Bamber, Bin Liu, Wenke Sun, and Qiuyu Wang

Status: open (until 18 Sep 2026)

Post a comment Subscribe to comment alert

RC1:
'Comment on egusphere-2026-3461', Anonymous Referee #1, 22 Aug 2026 reply
This manuscript uses three GRACE/GRACE-FO Mascon products from JPL, CSR, and GSFC spanning 2002–2024 to investigate interannual-to-decadal variability in glacier and ice-cap mass changes globally and across the Arctic. The authors apply ICA to extract the dominant spatiotemporal modes and relate them to the cumulative NAO index and cumulative PDO index. They then employ a multiple regression model incorporating a linear trend, annual and semiannual cycles, and the climate-mode indices to assess the influence of these climate modes on regional glacier mass variability and long-term trend estimates. However, several issues should be addressed before the manuscript can be considered for publication.
Major Comments
Equation (2) defines B as the mixing matrix. In the standard ICA formulation, if X denotes the observed signals, Y the independent source signals, and B the mixing matrix, the mixing model should be X = BY. However, Equation (2) in the manuscript is written as X = B⁻¹Y. Please clarify the definition of B and explain the reason for this formulation. If B actually denotes the unmixing/separation matrix (or its inverse), the notation and terminology should be revised consistently.

The relationship between NAO/PDO variability and Arctic glacier mass change has been widely recognized. In Sections 3.1 and 3.2, the ICA analysis demonstrates significant correlations between the dominant components of detrended glacier mass variability and the NAO/PDO indices. These results appear to establish the influence of NAO and PDO on interannual or low-frequency variability after removal of the linear trend, but they do not by themselves explain how these climate modes are related to the long-term mass-change trend. This distinction should be clarified, and additional evidence is needed to support any interpretation linking the ICA results to long-term trends.

The manuscript does not yet provide a sufficiently clear explanation of why NAO and PDO would affect the estimated long-term glacier mass-change trends. Is there an identifiable physical mechanism through which persistent phases or low-frequency variability of these climate modes project onto the finite GRACE/GRACE-FO observation period and thereby lead to an underestimation or overestimation of the long-term trend? A more explicit physical interpretation is needed to distinguish genuine climate-driven long-term changes from trend biases caused by decadal variability over a relatively short observational record.

I recommend comparing the corrected long-term trends with independent external observations, such as satellite altimetry or other available glacier mass-balance products. Such a comparison would provide an important validation of the proposed correction and help demonstrate whether accounting for the climate modes actually improves the trend estimates.

Minor Comments
For the “Spatial patterns” shown in Figures 1 and 2, please specify clearly whether they represent a particular time/epoch or a spatial pattern derived from or averaged over the entire study period.

The manuscript should be carefully checked for subject–verb agreement, wording, and terminology consistency. For example, in Section 4.1, “sustained meridional circulation are” should be changed to “sustained meridional circulation is,” or the subject should be rewritten in the plural. In addition, terms such as “Arctic ice mass variability” and “Arctic glacier mass variability” should be used consistently throughout the manuscript.

The upper and/or lower limits of the summation in Equation (1) appear to be written incorrectly. Please check and correct them.

Reply
Citation: https://doi.org/10.5194/egusphere-2026-3461-RC1

Xiaojun Ma, Matt King, Jonathan Bamber, Bin Liu, Wenke Sun, and Qiuyu Wang

Supplement

https://doi.org/10.5194/egusphere-2026-3461-supplement

Xiaojun Ma, Matt King, Jonathan Bamber, Bin Liu, Wenke Sun, and Qiuyu Wang

Viewed

Total article views: 225 (including HTML, PDF, and XML)

HTML	PDF	XML	Total	Supplement	BibTeX	EndNote
140	64	21	225	21	20	15

HTML: 140
PDF: 64
XML: 21
Total: 225
Supplement: 21
BibTeX: 20
EndNote: 15

Views and downloads (calculated since 08 Jul 2026)

Month	HTML	PDF	XML	Total
Jul 2026	104	39	15	158
Aug 2026	22	15	3	40
Sep 2026	14	10	3	27

Cumulative views and downloads (calculated since 08 Jul 2026)

Month	HTML	PDF	XML	Total
Jul 2026	104	39	15	158
Aug 2026	22	15	3	40
Sep 2026	14	10	3	27

Viewed (geographical distribution)

Total article views: 148 (including HTML, PDF, and XML) Thereof 148 with geography defined and 0 with unknown origin.

Country	#	Views	%

Latest update: 10 Sep 2026

Short summary

Satellite records of glacier change are only about two decades long, so short-term climate swings can strongly affect estimated trends. Using satellite gravity data, we show that the largest year-to-year changes in global glacier mass come from the Arctic and are linked to the North Atlantic Oscillation and Pacific Decadal Oscillation. Accounting for these effects makes Alaska’s estimated ice loss about one-third larger, improving interpretation of glacier change and future sea-level rise.


Total:	0
HTML:	0
PDF:	0
XML:	0