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

Climate data used as input to the climatic mass balance model.Downscaled air temperatures are shown in the first column, downscaled precipitation in the second column and cloud cover in the third column. Each line graph shows the outputs of ten different GCMs (colour code) and their means (black line). Ensembles belonging to the same RCP (2.6, 4.5, 6.0 and 8.5) are shown in the same row. The lower row shows a compilation of the respective means of the four RCPs.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4308701&req=5

f2: Climate data used as input to the climatic mass balance model.Downscaled air temperatures are shown in the first column, downscaled precipitation in the second column and cloud cover in the third column. Each line graph shows the outputs of ten different GCMs (colour code) and their means (black line). Ensembles belonging to the same RCP (2.6, 4.5, 6.0 and 8.5) are shown in the same row. The lower row shows a compilation of the respective means of the four RCPs.

Mentions: The spatially distributed mass balance model employed for this purpose was especially designed to reproduce local conditions on the ice cap12 on the basis of ERA-Interim data and has already been successfully used for a calculation of three decades of past CMB13. The model combines an accumulation scheme that is fitted to extensive field observations with a calibrated temperature-net radiation index approach for ablation modelling. The calculation of net shortwave radiation uses standard solar geometry algorithms and additionally accounts for modifications by cloud coverage and for temporally and spatially distributed surface albedo variations on the ice cap that are incorporated using a specially tailored minimal, statistical model33. Statistically downscaled daily air temperature and precipitation data as well as cloud cover data of the four climate-change scenarios Representative Concentration Pathways (RCP) 2.6, 4.5, 6.0 and 8.5 (ref. 34) are used as model input (Fig. 2). Each of these scenarios is represented by an ensemble of ten different GCM runs (Table S26) that were part of the Coupled Model Intercomparison Project Phase 5 (CMIP5). The ten GCMs are BCC-CSM1.1, CSIRO-Mk3.6.0, GFDL-ESM2G, HadGEM2-ES, IPSL-CM5A-LR, MIROC5, MIROC-ESM, MIROC-ESM-CHEM, MRI-CGCM3 and NorESM1-M.


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)

Climate data used as input to the climatic mass balance model.Downscaled air temperatures are shown in the first column, downscaled precipitation in the second column and cloud cover in the third column. Each line graph shows the outputs of ten different GCMs (colour code) and their means (black line). Ensembles belonging to the same RCP (2.6, 4.5, 6.0 and 8.5) are shown in the same row. The lower row shows a compilation of the respective means of the four RCPs.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f2: Climate data used as input to the climatic mass balance model.Downscaled air temperatures are shown in the first column, downscaled precipitation in the second column and cloud cover in the third column. Each line graph shows the outputs of ten different GCMs (colour code) and their means (black line). Ensembles belonging to the same RCP (2.6, 4.5, 6.0 and 8.5) are shown in the same row. The lower row shows a compilation of the respective means of the four RCPs.
Mentions: The spatially distributed mass balance model employed for this purpose was especially designed to reproduce local conditions on the ice cap12 on the basis of ERA-Interim data and has already been successfully used for a calculation of three decades of past CMB13. The model combines an accumulation scheme that is fitted to extensive field observations with a calibrated temperature-net radiation index approach for ablation modelling. The calculation of net shortwave radiation uses standard solar geometry algorithms and additionally accounts for modifications by cloud coverage and for temporally and spatially distributed surface albedo variations on the ice cap that are incorporated using a specially tailored minimal, statistical model33. Statistically downscaled daily air temperature and precipitation data as well as cloud cover data of the four climate-change scenarios Representative Concentration Pathways (RCP) 2.6, 4.5, 6.0 and 8.5 (ref. 34) are used as model input (Fig. 2). Each of these scenarios is represented by an ensemble of ten different GCM runs (Table S26) that were part of the Coupled Model Intercomparison Project Phase 5 (CMIP5). The ten GCMs are BCC-CSM1.1, CSIRO-Mk3.6.0, GFDL-ESM2G, HadGEM2-ES, IPSL-CM5A-LR, MIROC5, MIROC-ESM, MIROC-ESM-CHEM, MRI-CGCM3 and NorESM1-M.

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