Observations from Autonomous Ocean Flux Buoy 44 deployed at site L2 during the MOSAiC transpolar drift, Arctic Basin, 2019-2020

During the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition, four Autonomous Ocean Flux Buoys (AOFB) were set up on ice floes on the Siberian side of the Arctic Basin during October 2019 from the Academic Federov ice breaker. AOFB46 was located adjacent to the meteorology tower at the Central Observatory (CO) which was manned from the AWI (Alfred Wegener Institute) Polarstern ice breaker moored to the ice floe. AOFB43, 44, and 45 were deployed with other instrument systems at three remote sites – L1, L2 and L3, nominally 20 kilometer (km) out from the CO. The ice pack supporting the observation systems drifted across the Central Arctic toward Spitzbergen during the following 9 months. Data in this package from AOFB 44 is contained in a netCDF file with measurements of ocean variables that have been averaged onto 2-hour-long time intervals, the sample rate used for the ocean turbulence measurements. These timeseries are 1. The decimal yearday (yd) of 2019 of the middle of each 2 hour sample interval. 2. The Global positioning system (GPS)-derived latitude (lat) and longitude (lon) sampled at the center of each sample interval. 3. Eastward and Northward absolute ocean velocity profiles including ice velocity derived from the AOFB position, 5 meter (m) currents measured by the turbulence sensor package, and Acoustic Doppler Current Profiler (ADCP) time series of earth-referenced currents from 10m to 80m depth sampled every 2m. Exact measurement depths are contained in the depth vector variable z. 4. Reynolds stress components rho <u'w'> and rho <v'w'>, heat flux rho cp <T’w’>, and salt flux <S’w’>, measured by the turbulence sensor nominally at 5m depth from 2 Hertz (Hz) sampled 35 minute ensembles of high resolution velocity, temperature and conductivity timeseries. Here ρ is the in situ seawater density and cp is the specific heat of seawater.