Figure 5
From: Projections of the future disappearance of the Quelccaya Ice Cap in the Central Andes
ELA projections at QIC. Equilibrium-line altitude (ELA) calculated using the freezing level height anomaly projections at QIC (FLHatm) from 16 CMIP5 models as input in equation (1). FLHatm was obtained by interpolating Ta and Zg between 500 and 600 hPa pressure levels. The black curve (OBS) represents the observed ELA obtained from LANDSAT satellite images over the 1992–2017 period. Bias-correction was applied to Ta and ELA for each CMIP5 model, using the observed Ta from the AWS at QIC. The hydrological year Sept.-Aug. was used for calculations. The ensemble of historical (1950–2005) simulations is represented with the gray line, while CMIP5 RCP4.5 and RCP8.5 future projections (2006–2100) are represented by green and orange lines, respectively. The shading represents the corresponding 95% confidence intervals. The blue dashed line indicates the QIC summit altitude (~5680 m a.s.l.). The mean observed ELA over the 1992–2017 period was 5435 m a.s.l., and the mean ERA-interim ELA over the baseline 1979–2017 was 5416 m a.s.l. Likely ranges for ELA projections at QIC by the end of the 21st century are indicated by vertical bars.
