Physical and chemical oceanography in the Arctic Ocean

• Main Author: Bauch, Dorothea
• Format: Other/Unknown Material
• Language: English
• Published: PANGAEA 1995
• Subjects: 91004; 91008; Arctic Ocean; ARK-IV/2; ARK-IV/3; AWI_Paleo; Chejsa Island; CTD/Rosette; CTD-RO; Dalniye Zelentsy; DZ-68; DZ-68_1; DZ-68_10; DZ-68_11; DZ-68_12; DZ-68_13; DZ-68_14; DZ-68_15; DZ-68_16; DZ-68_2; DZ-68_3; DZ-68_5; DZ-68_8; DZ-68_9; E.S.A.R.E.92; ESARE92/14; ESARE92/17; ESARE92/2; ESARE92/3; ESARE92/4; ESARE92/5; ESARE92/6; ESARE92/7; ESARE92/8; Green Bell Island; Greenland Sea; M71; M71_79; M8/1; M8/1_617; Meteor (1964); Meteor (1986); MULT; Multiple investigations; Nordenskiöld Bay; North Greenland Sea; OD91; OD91_004; OD91_008; OD91_009-1; amundsen basin; Arctic; Bell Island; Berichte zur Polarforschung; Bering Strait; Fram Strait; Greenland; Nansen Basin; North Greenland; oden; Polar Research; Polarforschung; Reports on polar research; Sea ice
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.761145; https://doi.org/10.1594/PANGAEA.761145

Data from sections across the Eurasian Basin of the Arctic Ocean occupied by the German Research Vessel Polarstern in 1987 and by the Swedish icebreaker Oden in 1991 are used to derive information on the freshwater balance of the Arctic Ocean halocline and on the sources of the deep waters of the Nansen, Amundsen and Makarov basins. Salinity, d18O and mass balances allow separation of the river-runoff and the sea-ice meltwater fractions contained in the Arctic halocline. This provides the basis for tracking the river-runoff signal from the shelf seas across the central Arctic Ocean to Fram Strait. The halocline has to be divided into at least three lateral regimes: the southern Nansen Basin with net sea-ice melting, the northern Nansen Basin and Amundsen Basin with net sea-ice formation and increasing river-runoff fractions, and the Canadian Basin with minimum sea-ice meltwater and maximum river-runoff fractions and water of Pacific origin. In the Canadian Basin, silicate is used as a tracer to identify Pacific water entering through Bering Strait and an attempt is made to quantify its influence on the halocline waters of the Canadian Basin. For this purpose literature data from the CESAR and LOREX ice camps are used. Based on mass balances and depending on the value of precipitation over the area of the Arctic Ocean the average mean residence time of the river-runoff fraction contained in the Arctic Ocean halocline is determined to be about 14 or 11 years. Water column inventories of river-runoff and sea-ice meltwater are calculated for a section just north of Fram Strait and implications for the ice export rate through Fram Strait are discussed. Salinity, tritium, 3He and the d18O ratio of halocline waters sampled during the 1987 Polarstern cruise to the Nansen Basin are used to estimate the mean residence time of the river-runoff component in the halocline and on the shelves of the Arctic Ocean. These estimates are done by comparing ages of the halocline waters based on a combination of tracers yielding ...