Subglacial hydrology directly impacts glacier motion, but few studies have investigated the connections between ice speed and water input on regional scales. Here, we analyze the correlation of glacier surface speed and runoff for 77 glaciers ≥3 km2 (~3070 km2) on the Kenai Peninsula, Alaska, within and between seasons from 2015-2019. Most correlations between monthly/seasonal mean ice speed and cumulative runoff in preceding months/multi-month periods are significant (p<0.05), while correlations for the same months or seasons are generally insignificant or weak indicating seasonally delayed responses of ice speed to runoff. In almost all cases lower-than-average monthly/seasonal ice speeds are associated with higher-than-average runoff in preceding months or multi-month periods. Overall, our results show that runoff can influence ice speed with considerable (multi-month) delays.

Modeling future glacier changes on regional or global scales is challenging due to a scarcity of data for calibrating model parameters. This makes it difficult to derive accurate model parameters and also to convey the model uncertainty associated with those parameters. Previous global-scale models have typically optimized a single glacier or region specific set of model parameters to project global-scale glacier mass changes. As part of the development of a new open source global-scale glacier evolution model this research implements a Markov Chain Monte Carlo method to address this problem. We use geodetic mass-balance observations to determine probability distributions of a set of model parameters at each glacier. We then form an ensemble of model simulations by sampling parameters from these distributions. Using an ensemble allows us to create a range of mass balance changes for each glacier and quantify the model uncertainty. Applying this calibration technique, we use temperature and precipitation projections of one global climate model to model the mass changes until year 2100 of thousands of glaciers in High Mountain Asia. By using climate projections forced by multiple emission scenarios, we compare the uncertainties in changing climate caused by possible emission scenarios with the uncertainties in the glacier evolution model, and evaluate the results of different climate scenarios on glacier evolution.