The annual deployment of the mass balance probe started off the season. Andy Mahoney, Marcel Nicolaus (AWI) and myself defined the location for this year’s Mass Balance Probe, did snow and ice characterizations, deployed the Mass Balance probe and optical instruments, and checked on the RADAR downtown. New this year is a slight re-design of the mass balance probe that allowed the deployment in one day, without having to wait for equipment to freeze in (we are also anticipating that this design is more stable during the melt season). So we did it: scouted out the site (the ice is very deformed this year (rubble ice), while we need a patch of undeformed ice) and took ice cores until a core got frozen inside the core barrel on Saturday (yes: arrival in Barrow, check-in procedures with CPS/Umiaq, gathering equiment from cold storage, defining the field site, taking ice cores, and returning safely to NARL — all before it got dark), prepared equipment on Sunday, and deployed the probe including wind turbine on Monday. Turns out, Monday was the coldest day of this winter season so far with temperatures as low as -42°C. Needless to say, we were efficient as can be and deployed the instruments in record time (3.5 hours, including the snow machine ride to and from the site). Tuesday was warmer when we deployed the optical instruments of AWI, also including a wind turbine. Temperatures continued to rise when we looked after the RADAR, filtered samples, and continued with snow and ice characterizations the following days. We had significant winds only on the last day which left us reassured that the wind turbine was spinning. Sunrise and sunset were beautiful to look at as we had clear skies when the sun started to re-appear after the longest night in Barrow. This was our first trip supported by Umiaq instead of BASC, and although we were bracing ourselfs for hick-ups during the transition, it went very smoothly.