The geodetic mass balance of Eyjafjallajökull ice cap for 1945–2014: processing guidelines and relation to climate

Mass-balance measurements of Icelandic glaciers are sparse through the 20th century. However, the large archive of stereo images available allows estimates of glacier-wide mass balance ( Ḃ ) in decadal time steps since 1945. Combined with climate records, they provide further insight into glacier–climate relationship. This study presents a workflow to process aerial photographs (1945–1995), spy satellite imagery (1977–1980) and modern satellite stereo images (since 2000) using photogrammetric techniques and robust statistics in a highly automated, open-source pipeline to retrieve seasonally corrected, decadal glacier-wide geodetic mass balances. In our test area, Eyjafjallajökull (S-Iceland, ~70 km2), we obtain a mass balance of $<![CDATA[ $ Ḃ₁₉₄₅²⁰¹⁴ = -0.27 ± 0.03\,{ m\ w}{. e}{.} { a}^{{ 1}}$ , with a maximum and minimum of $ Ḃ₁₉₈₄¹⁹⁸⁹ = 0.77 ± 0.19\,{ m\ w}{ . e}{ .} { a}^{{ 1}}$ and $ Ḃ₁₉₉₄¹⁹⁹⁸ = -1.94 ± 0.34\,{ m\ w}{ . e}{ .} { a}^{{ 1}}$ , respectively, attributed to climatic forcing, and $ Ḃ₂₀₀₉²⁰¹⁰ = -3.39{ \;} ± { \;} 0.43\,{ m\ w}{ . e}{ .} { a}^{{ 1}}$ , mostly caused by the April 2010 eruption. The reference-surface mass balances correlate with summer temperature and winter precipitation, and linear regression accounts for 80% of the mass-balance variability, yielding a static sensitivity of mass balance to summer temperature and winter precipitation of − 2.1 ± 0.4 m w.e.a–1K–1and 0.5 ± 0.3 m w.e.a–1(10%)–1, respectively. This study serves as a template that can be used to estimate the mass-balance changes and glaciers' response to climate.