Surface ablation rates were measured daily using changes in ice surface height at five ablation stakes arranged in a cross configuration at ~2 m separation. The stakes were located in the supraglacial hydrological catchment feeding Moulin L41A. The stakes were installed in holes deeper than the length of the stake (so each measurement of ice surface height was made from the ice surface down to the top of the stake) to avoid the problem of enhanced surface melting caused by solar radiation absorbed by the stake. All ablation measurements were carried out by the same observer to ensure consistency for example in the interpretation of the level of a rough ice surface. A full description was provided by Chandler et al. (2015) at https://doi.org/10.5194/tc-9-487-2015.

Date of measurement representing ablation from evening of previous day to evening of current day. Times are UTC-3.