The APMB project aims to make, for the first time, an assessment of mass balance specifically dedicated to the Antarctic Peninsula. The Antarctic Peninsula (AP) is a critical area of study because environmental changes across the region over the past decades have been among some of the most extreme to have been observed globally. Specifically, it is one of the most rapidly warming regions on Earth, with observations showing increases in both air and ocean temperatures. This has been linked to widespread ice shelf retreat and collapse, glacier thinning and ice mass loss. The Ice Sheet Mass Balance Intercomparison Exercise (IMBIE) showed that between 1992 and 2011 the AP accounted for around 25% of the total Antarctic mass loss despite occupying only 4% of the total area.

Notwithstanding its global significance, the AP remains a challenging area to monitor. The APMB project was as such motivated by the IMBIE community assessment, which identified the Antarctic Peninsula as a region where further study was required in order to improve mass change estimates for the region. Although consensus between the three techniques was reached during IMBIE, it was widely acknowledged by participants that the Antarctic Peninsula, due to it mountainous terrain and locally, highly variable glacier behaviour, was a difficult region for all three techniques. Ultimately, this led to lower confidence in the individual results and an absence of an estimate from radar altimetry. The new and improved assessment of AP mass balance made by the APMB project is therefore being achieved by tailoring the individual techniques of gravimetry, altimetry and IOM to the specific characteristics of the AP, and combining the estimates in such a way as to take advantage of their complementarity in coverage and resolution. Specifically, we combine satellite data from ERS-1 and-2, EnviSat and CryoSat-2 (altimetry), ERS-1 and -2, ALOS PALSAR, TerraSAR-X and Sentinel-1 (ice velocity) and GRACE gravimetry, together with airborne measurements and surface mass balance models to develop a detailed, reconciled and consolidated history of AP evolution during the last two decades. In doing so, we seek to increase the confidence in our mass balance assessment of this difficult region and better constrain its contribution to global mean sea level rise.