ALBERT

Description: The radar system on board of Polarstern features a rotating antenna that is mounted on the observation deck, above the bridge. The antenna transmit microwave pulses at short intervals, which are reflected back to the radar system by the water or pack ice. This produces an image of the positions of ice floes within a radius of 3 nautical miles (ca. 5,4 km) and their sizes in relation to the ship. The imaging technique offers an undiminished view and remains unaffected by weather or darkness, i.e., it can penetrate rain clouds and fog and therefore offers an undiminished view even at night. The sector without information is blogged by ship facilities. The RV Polarstern's marine radar systems operated throughout the drift phase of MOSAiC. The imaging system, which shows Polarstern in the centre of the screen, offers vital information on floe movements, deformation and formation of cracks in the ship's immediate vicinity.

Description: This bibliography unites the individual data collected by different types of autonomous platforms deployed during MOSAiC in 2019/2020.

Description: Temperature and heating-induced temperature differences were measured along a chain of thermistors. SIMBA 2019T56 (a.k.a. FMI_05_06, IRIDIUM number 300234065176750) is an autonomous instrument that was installed on drifting sea ice in the Arctic Ocean during the 1st leg of the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) in November 2019. The buoy was deployed at the ~2 km from the ship at the SW direction with initial thicknesses of snow and ice of 0.18 and 0.42 m, respectively, on 2 November 2019. The thermistor chain was 5 m long and included 241 sensors with a regular spacing of 2cm. The depths for the sensors are 80 to -398 cm, referring to the initial interface between snow and ice. The last sensor was used to measure the air temperature at 1 m above the initial snow surface. The resulting time series describes the evolution of temperature and temperature differences after two heating cycles of 30 and 120 s as a function of depth and time between 2 November 2019 and 2 July 2020 in sample intervals of 6 hours for temperature and 24 hours for temperature differences. In addition to temperature, geographic position, barometric pressure, tilt and compass were measured.

Description: We present sea ice temperature and salinity data from first-year ice (FYI) and second-year ice (SYI) relevant to the temporal development of sea ice permeability and brine drainage efficiency from the early growth phase in October 2019 to the onset of spring warming in May 2020. Our dataset was collected in the central Arctic Ocean during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) Expedition in 2019 to 2020. MOSAiC was an international transpolar drift expedition in which the German icebreaker RV Polarstern anchored into an ice floe to gain new insights into Arctic climate over a full annual cycle. In October 2019, RV Polarstern moored to an ice floe in the Siberian sector of the Arctic at 85 degrees north and 137 degrees east to begin the drift towards the North Pole and the Fram Strait via the Transpolar Drift Stream. The data presented here were collected during the first three legs of the expedition, so all the coring activities took place on the same floe. The end dates of legs 1, 2, and 3 were 13 December, 24 February, and 4 June, respectively. The dataset contributed to a baseline study entitled, Deciphering the properties of different Arctic ice types during the growth phase of the MOSAiC floes: Implications for future studies. The study highlights downward directed gas pathways in FYI and SYI by inferring sea ice permeability and potential brine release from several time series of temperature and salinity measurements. The physical properties presented in this paper lay the foundation for subsequent analyses on actual gas contents measured in the ice cores, as well as air-ice and ice-ocean gas fluxes. Sea ice cores were collected with a Kovacs Mark II 9 cm diameter corer. To measure ice temperatures, about 4.5 cm deep holes were drilled into the core (intervals varied by site and leg) . The temperatures were measured by a digital thermometer within minutes after the cores were retrieved. The ice cores were placed into pre-labelled plastic sleeves sealed at the bottom end. The ice cores were transported to RV Polarstern and stored in a -20 degrees Celsius freezer. Each of the cores was sub-sampled, melted at room temperature, and processed for salinity within one or two days. The practical salinity was estimated by measuring the electrical conductivity and temperature of the melted samples using a WTW Cond 3151 salinometer equipped with a Tetra-Con 325 four-electrode conductivity cell. The practical salinity represents the the salinity estimated from the electrical conductivity of the solution. The dataset also contains derived variables, including sea ice density, brine volume fraction, and the Rayleigh number.

Description: Temperature and heating-induced temperature were measured along a chain of thermistors. Digital Thermistor Chain DTC15 is an autonomous instrument that was installed on drifting sea ice in the Arctic Ocean during the MOSAiC expedition on 07 November 2019. The thermistor chain was 4.16 m long and included sensors with a regular spacing of 2 cm. The resulting time series describes the evolution of temperature during the heating cycle of 20 s and after the heating cycle during the following 40 s as a function of geographic position (GPS), depth, and time between 05 November 2019 and 07 January 2020 in sample intervals of 6 hours. It also contains manually estimated positions of air-snow, snow-ice, and ice-water interfaces. The DTC was installed in the deformed second-year ice ridge next to RV Polarstern and remote sensing site RS1.

Description: Temperature and heating-induced temperature were measured along a chain of thermistors. Digital Thermistor Chain DTC31 is an autonomous instrument that was installed on drifting sea ice in the Arctic Ocean during the MOSAiC expedition on 22 November 2020. The thermistor chain was 5.12 m long and included sensors with a regular spacing of 2 cm. The resulting time series describes the evolution of temperature during the heating cycle of 20 s and after the heating cycle during the following 40 s as a function of geographic position (GPS), depth, and time between 22 November 2019 and 15 July 2020 in sample intervals of 6 hours. It also contains manually estimated positions of air-snow, snow-ice, and ice-water interfaces. The DTC was installed in deformed second-year ice at Transect North. Radiation station 2020R14 was installed next to the DTC31: doi:10.1594/PANGAEA.948572.

Description: Temperature and heating-induced temperature were measured along a chain of thermistors. Digital Thermistor Chain DTC33 is an autonomous instrument that was installed on drifting sea ice in the Arctic Ocean during the MOSAiC expedition on 22 November 2020. The thermistor chain was 5.12 m long and included sensors with a regular spacing of 2 cm. The resulting time series describes the evolution of temperature during the heating cycle of 20 s and after the heating cycle during the following 40 s as a function of geographic position (GPS), depth, and time between 22 November 2019 and 15 July 2020 in sample intervals of 6 hours. It also contains manually estimated positions of air-snow, snow-ice, and ice-water interfaces. The DTC was installed in undeformed second-year ice at Transect North: https://doi.org/10.1525/elementa.2022.00048. Radiation station 2020R14 was installed next to the DTC33: doi:10.1594/PANGAEA.948572.

Description: Temperature and heating-induced temperature were measured along a chain of thermistors. Digital Thermistor Chain DTC32 is an autonomous instrument that was installed on drifting sea ice in the Arctic Ocean during the MOSAiC expedition on 22 November 2020. The thermistor chain was 5.12 m long and included sensors with a regular spacing of 2 cm. The resulting time series describes the evolution of temperature during the heating cycle of 20 s and after the heating cycle during the following 40 s as a function of geographic position (GPS), depth, and time between 22 November 2019 and 15 July 2020 in sample intervals of 6 hours. It also contains manually estimated positions of air-snow, snow-ice, and ice-water interfaces. The DTC was installed in deformed second-year ice at Transect North. Radiation station 2020R14 was installed next to the DTC32: doi:10.1594/PANGAEA.948572.

Description: Temperature profile from atmosphere through snow and ice into the ocean.