Limits...
Temporal constraints on future accumulation-area loss of a major Arctic ice cap due to climate change (Vestfonna, Svalbard).

Möller M, Schneider C - Sci Rep (2015)

Bottom Line: Results indicate strongly decreasing climatic mass balances over the 21(st) century for all RCPs considered.Glacier-wide mass-balance rates will drop down to -4 m a(-1) w.e. (water equivalent) at a maximum.The date at which the equilibrium line rises above the summit of Vestfonna (630 m above sea level) is calculated to range between 2040 and 2150, depending on scenario.

View Article: PubMed Central - PubMed

Affiliation: 1] Department of Geography, RWTH Aachen University, Wüllnerstraβe 5b, 52056 Aachen, Germany [2] Departamento Matemática Aplicada, E.T.S.I. Telecomunicación, Universidad Politécnica de Madrid, Avenida Complutense 30, 28040 Madrid, Spain.

ABSTRACT
Arctic glaciers and ice caps are major contributors to past, present and future sea-level fluctuations. Continued global warming may eventually lead to the equilibrium line altitudes of these ice masses rising above their highest points, triggering unstoppable downwasting. This may feed future sea-level rise considerably. We here present projections for the timing of equilibrium-line loss at the major Arctic ice cap Vestfonna, Svalbard. The projections are based on spatially distributed climatic mass balance modelling driven by the outputs of multiple climate models from the Coupled Model Intercomparison Project Phase 5 (CMIP5) forced by the Representative Concentration Pathways (RCPs) 2.6, 4.5, 6.0 and 8.5. Results indicate strongly decreasing climatic mass balances over the 21(st) century for all RCPs considered. Glacier-wide mass-balance rates will drop down to -4 m a(-1) w.e. (water equivalent) at a maximum. The date at which the equilibrium line rises above the summit of Vestfonna (630 m above sea level) is calculated to range between 2040 and 2150, depending on scenario.

No MeSH data available.


Related in: MedlinePlus

Timing of equilibrium-line loss for the four RCPs.Timings for the individual GCMs of the respective ensemble members are indicated by colour code. For GCMs where no permanent equilibrium-line loss is observed during the modelling period, the timings are derived from extrapolations of the linear temporal trends. In this case also the 95% confidence intervals of the linear fits are shown. The period before equilibrium-line loss is calculated from the mean ELA time series shown in Figure 5.
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f6: Timing of equilibrium-line loss for the four RCPs.Timings for the individual GCMs of the respective ensemble members are indicated by colour code. For GCMs where no permanent equilibrium-line loss is observed during the modelling period, the timings are derived from extrapolations of the linear temporal trends. In this case also the 95% confidence intervals of the linear fits are shown. The period before equilibrium-line loss is calculated from the mean ELA time series shown in Figure 5.

Mentions: The dates of equilibrium-line loss, i.e. of the dates when the projected ELAs exceed the summit altitude of Vestfonna and the extent of the accumulation area reduces to zero, range between 2043/2044 (RCP 8.5) and 2151/2152 (RCP 2.6) (Fig. 6, Table 1). While the initial AAR of Vestfonna, 0.59 ± 0.06 (mean ± one standard deviation of all 40 ensemble members) during the first decade of modelling, indicates a quasi steady-state glacier, this situation rapidly changes over the modelling period. Halving of the initial AAR already occurs between the 2020s (RCP 8.5) and the 2080s (RCP 2.6) (Table 1).


Temporal constraints on future accumulation-area loss of a major Arctic ice cap due to climate change (Vestfonna, Svalbard).

Möller M, Schneider C - Sci Rep (2015)

Timing of equilibrium-line loss for the four RCPs.Timings for the individual GCMs of the respective ensemble members are indicated by colour code. For GCMs where no permanent equilibrium-line loss is observed during the modelling period, the timings are derived from extrapolations of the linear temporal trends. In this case also the 95% confidence intervals of the linear fits are shown. The period before equilibrium-line loss is calculated from the mean ELA time series shown in Figure 5.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4308701&req=5

f6: Timing of equilibrium-line loss for the four RCPs.Timings for the individual GCMs of the respective ensemble members are indicated by colour code. For GCMs where no permanent equilibrium-line loss is observed during the modelling period, the timings are derived from extrapolations of the linear temporal trends. In this case also the 95% confidence intervals of the linear fits are shown. The period before equilibrium-line loss is calculated from the mean ELA time series shown in Figure 5.
Mentions: The dates of equilibrium-line loss, i.e. of the dates when the projected ELAs exceed the summit altitude of Vestfonna and the extent of the accumulation area reduces to zero, range between 2043/2044 (RCP 8.5) and 2151/2152 (RCP 2.6) (Fig. 6, Table 1). While the initial AAR of Vestfonna, 0.59 ± 0.06 (mean ± one standard deviation of all 40 ensemble members) during the first decade of modelling, indicates a quasi steady-state glacier, this situation rapidly changes over the modelling period. Halving of the initial AAR already occurs between the 2020s (RCP 8.5) and the 2080s (RCP 2.6) (Table 1).

Bottom Line: Results indicate strongly decreasing climatic mass balances over the 21(st) century for all RCPs considered.Glacier-wide mass-balance rates will drop down to -4 m a(-1) w.e. (water equivalent) at a maximum.The date at which the equilibrium line rises above the summit of Vestfonna (630 m above sea level) is calculated to range between 2040 and 2150, depending on scenario.

View Article: PubMed Central - PubMed

Affiliation: 1] Department of Geography, RWTH Aachen University, Wüllnerstraβe 5b, 52056 Aachen, Germany [2] Departamento Matemática Aplicada, E.T.S.I. Telecomunicación, Universidad Politécnica de Madrid, Avenida Complutense 30, 28040 Madrid, Spain.

ABSTRACT
Arctic glaciers and ice caps are major contributors to past, present and future sea-level fluctuations. Continued global warming may eventually lead to the equilibrium line altitudes of these ice masses rising above their highest points, triggering unstoppable downwasting. This may feed future sea-level rise considerably. We here present projections for the timing of equilibrium-line loss at the major Arctic ice cap Vestfonna, Svalbard. The projections are based on spatially distributed climatic mass balance modelling driven by the outputs of multiple climate models from the Coupled Model Intercomparison Project Phase 5 (CMIP5) forced by the Representative Concentration Pathways (RCPs) 2.6, 4.5, 6.0 and 8.5. Results indicate strongly decreasing climatic mass balances over the 21(st) century for all RCPs considered. Glacier-wide mass-balance rates will drop down to -4 m a(-1) w.e. (water equivalent) at a maximum. The date at which the equilibrium line rises above the summit of Vestfonna (630 m above sea level) is calculated to range between 2040 and 2150, depending on scenario.

No MeSH data available.


Related in: MedlinePlus