Climate on the Blanca Massif, Sangre de Cristo Mountains, Colorado, USA, during the Last Glacial Maximum

Temperature-index modeling is used to determine the magnitude of temperature depression on Blanca Massif, Colorado, required maintain steady-state mass balances nine reconstructed glaciers at their extent during Last Glacial Maximum (LGM). The mean thus determined ~8.6 +0.7/?0.9 °C where uncertainties account for those inherent in glacier reconstructions, model parameters (e.g., melt factors), and possible modest changes LGM precipitation. Associated equilibrium-line altitudes (ELAs) exhibit a statistically significant directional dependency being lower toward north east. Under assumption that regional change was uniform, precipitation vary systematically—also exhibiting coinciding with ELAs—and indicate increases (over modern) occurred eastern side massif while decreases western side. This disparity represents strengthening asymmetry, particularly winter precipitation, which exists today. modern asymmetry may be consequence snow blown over (advective transport) by southwesterly flow. Intensification this flow would have enhanced advection, augmented accumulation glaciers, explaining ELAs increased massif.