Separating Long‐Term and Short‐Term Mass Changes of Antarctic Ice Drainage Basins: A Coupled State Space Analysis of Satellite Observations and Model Products

Willen, Matthias O.; Broerse, Taco; Groh, Andreas; Wouters, Bert; Munneke, Peter Kuipers; Horwath, Martin; Broeke, M. R. van den; Schröder, Ludwig

doi:10.1029/2020jf005966

Cited by 7 publications

(6 citation statements)

References 52 publications

(141 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This applies in particular to the SAM which exhibits not only considerable variations but also a long-term shift to its positive phase due to anthropogenic climate change (34 ). While variability over these timescales can be treated as a stochastic process (5,6 ), our approach is to take advantage of the indicated and expected link with physical processes expressed in climate index variability. Specifically, the above EOF analysis, which is a purely data-driven and objective approach to identifying dominant modes of variability, inspires us to construct a regression model including both SAM Σ and Niño3.4 Σ to further quantify their contributions to ice-mass change.…”

Section: Resultsmentioning

confidence: 99%

Climate variability as a major forcing of recent Antarctic ice-mass change

King

Lyu

Zhang

2023

Preprint

View full text Add to dashboard Cite

Antarctica has been losing ice mass for decades, but its link to large-scale climate forcing is not clear. Shorter-period variability has been partly associated with El Niño Southern Oscillation (ENSO), but a clear connection with the dominant climate mode, the Southern Annular Mode (SAM), is yet to be found. We show that space gravimetric estimates of ice-mass variability over 2002-2021 may be substantially explained by a simple linear relation with detrended, time-integrated SAM and ENSO indices, from the whole ice sheet down to individual drainage basins. Approximately 40% of the ice-mass trend can be ascribed to increasingly persistent positive SAM forcing which, since the 1940s, is likely due to anthropogenic activity. Similar attribution over 2002-2021 could connect recent ice-sheet change to human activity. Main TextThe rate at which the mass of the Antarctic Ice Sheet (AIS) has reduced over recent decades has fluctuated, resulting in changes to the rate of contribution to sea-level change over time(1, 2 ). This is reflected in analyses of satellite observations shifting from quantification of a single linear rate of change(3, 4 ) to estimating time-varying rates of change that vary over months to decades(1, 2, 5, 6 ). These changing rates are in response to external and internal forcing that is not fully understood but understanding them, and attributing them to different drivers, would provide important insight into the extent these changes will extend into the future. Using near-continuous records of ice volume change since the early 1990s, and of mass change since 2002, studies have begun to explore the potential large-scale climatological forcing(7 ) of the ice-sheet's change through comparing observed high frequency or single event changes with climate indices that reflect climate variability, notably with the El Niño Southern Oscillation (ENSO) (5,(8)(9)(10)(11).

show abstract

Section: Resultsmentioning

confidence: 99%

Climate variability as a major forcing of recent Antarctic ice-mass change

King

Lyu

Zhang

2023

Preprint

View full text Add to dashboard Cite

show abstract

“…Elevated IVT conditions over ice surfaces have been shown to negatively impact ice sheet mass balances. Atmospheric river landfalls have been shown drive melt over the ice shelves around the Antarctic Peninsula (Wille et al., 2019, 2021) and the Greenland Ice Sheet (Mattingly et al., 2020, 2023). This melt results from adiabatic heating as a result of foehn wind generation (Bozkurt et al., 2018; Mattingly et al., 2023; Wille et al., 2019, 2021) and radiation as a consequence of cloud formation over the ice surface (e.g., Mattingly et al., 2018, 2020; Wille et al., 2019).…”

Section: Discussionmentioning

confidence: 99%

“…Atmospheric river landfalls have been shown drive melt over the ice shelves around the Antarctic Peninsula (Wille et al., 2019, 2021) and the Greenland Ice Sheet (Mattingly et al., 2020, 2023). This melt results from adiabatic heating as a result of foehn wind generation (Bozkurt et al., 2018; Mattingly et al., 2023; Wille et al., 2019, 2021) and radiation as a consequence of cloud formation over the ice surface (e.g., Mattingly et al., 2018, 2020; Wille et al., 2019). At the same time, snowfall resulting from elevated IVT may replace lost mass from the Antarctic Ice Sheet (e.g., Boening et al., 2012).…”

Section: Discussionmentioning

confidence: 99%

“…The mass balance of the Antarctic ice sheet (AIS) is a key factor controlling the rate of sea level rise (Rignot et al., 2011). Satellite observations over the past three decades show an accelerating negative mass balance across the AIS since 1979 (e.g., Pattyn & Morlighem, 2020; Rignot et al., 2019; Shepherd et al., 2019; Slater et al., 2021; Willen et al., 2021). However, individual regions of the AIS have disparate mass balance trends, with some regions losing ice at accelerating rates, while others are stable or gaining mass (Edwards et al., 2019; Rignot et al., 2019; Willen et al., 2021).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

CloudSat Observations Show Enhanced Moisture Transport Events Increase Snowfall Rate and Frequency Over Antarctic Ice Sheet Basins

Rendfrey,

Pettersen,

Bassis

et al. 2024

JGR Atmospheres

View full text Add to dashboard Cite

Elevated moisture transport over the Antarctic ice sheet can increase snowfall and ice mass. Previous studies used ground‐based observations, reanalysis products, and atmospheric models to evaluate the relationship between extreme moisture transport and snowfall properties. Here, we build on previous studies by combining reanalysis and CloudSat radar snowfall retrievals to examine impacts of extreme moisture intrusions on changes in snowfall frequency and intensity over glacier basins on the Antarctic ice sheet. We examine the impacts of enhanced moisture transport events on snowfall frequency and intensity over two different regions on the Antarctic ice sheet: the Amery Ice Shelf of East Antarctica and the Thwaites and Pine Island glacier basins of West Antarctica. We determine when the median integrated water vapor transport from reanalysis exceeds the 95th percentile within the glacier basins of interest to define enhanced moisture transport events. We then use CloudSat radar snowfall retrievals to evaluate differences between snowfall frequency and intensity during enhanced water vapor transport events compared to the seasonal means for 2007–2010. We find that enhanced moisture transport events over the Amery Ice Shelf and Thwaites and Pine Island glacier basins coincide with higher snowfall frequency and intensity. These enhanced moisture transport events have the potential to alter surface mass balance within glacier basins, with implications for future rates of sea level rise.

show abstract

“…(4) In the synthetic experiments, we incorporate mean rates of IMC and FAC only. We did not yet generalize the approach to analyse interannual variations of IMC and FAC or to analyse time-variable rates of the ice dynamic contribution to the mass balance which are in particular present in the West Antarctic Ice Sheet (Willen et al 2021).…”

Section: Conceptual Assumptionsmentioning

confidence: 99%

Feasibility of a global inversion for spatially resolved glacial isostatic adjustment and ice sheet mass changes proven in simulation experiments

Willen

Horwath

Groh

et al. 2022

J Geod

Self Cite

View full text Add to dashboard Cite

Estimating mass changes of ice sheets or of the global ocean from satellite gravimetry strongly depends on the correction for the glacial isostatic adjustment (GIA) signal. However, geophysical GIA models are different and incompatible with observations, particularly in Antarctica. Regional inversions have resolved GIA over Antarctica without ensuring global consistency, while global inversions have been mostly constrained by a priori GIA patterns. For the first time, we set up a global inversion to simultaneously estimate ice sheet mass changes and GIA, where Antarctic GIA is spatially resolved using a set of global GIA patterns. The patterns are related to deglaciation impulses localized along a grid over Antarctica. GIA associated with four regions outside Antarctica is parametrized by global GIA patterns induced by deglaciation histories. The observations we consider here are satellite gravimetry, satellite altimetry over Antarctica and Greenland, as well as modelled firn thickness changes. Firn thickness changes are also parametrized to account for systematic errors in their modelling. Results from simulation experiments using realistic signals and error covariances support the feasibility of the approach. For example, the spatial RMS error of the estimated Antarctic GIA effect, assuming a 10-year observation period, is 31% and 51%, of the RMS of two alternative global GIA models. The integrated Antarctic GIA error is 8% and 5%, respectively, of the integrated GIA signal of the two models. For these results realistic error covariances incorporated in the parameter estimation process are essential. If error correlations are neglected, the Antarctic GIA RMS error is more than twice as large.Highlights$$\bullet $$ ∙ We present a globally consistent inversion approach to co-estimate glacial isostatic adjustment effects together with changes of the ice mass and firn air content in Greenland and Antarctica. $$\bullet $$ ∙ The inversion method utilizes data sets from satellite gravimetry, satellite altimetry, regional climate modelling, and firn modelling together with the full error-covariance information of all input data. $$\bullet $$ ∙ The simulation experiments show that the proposed GIA parametrization in Antarctica can resolve GIA effects unpredicted by geophysical modelling, despite realistic input-data limitations.

show abstract

Separating Long‐Term and Short‐Term Mass Changes of Antarctic Ice Drainage Basins: A Coupled State Space Analysis of Satellite Observations and Model Products

Cited by 7 publications

References 52 publications

Climate variability as a major forcing of recent Antarctic ice-mass change

Climate variability as a major forcing of recent Antarctic ice-mass change

CloudSat Observations Show Enhanced Moisture Transport Events Increase Snowfall Rate and Frequency Over Antarctic Ice Sheet Basins

Feasibility of a global inversion for spatially resolved glacial isostatic adjustment and ice sheet mass changes proven in simulation experiments

Contact Info

Product

Resources

About