Proposal Number: OPP 9622603 Principal Investigator: Falkner, Kelly ABSTRACT Among the outstanding issues regarding Arctic Ocean circulation are the fate of its riverine inputs and the nature of the processes ventilating sub-surface waters of its interior. Circulation and material transport and transformation in the Arctic needs to be more completely characterized because of the potentially critical role the Arctic plays in global themohaline circulation and on a more immediate timescale, because of the need to predict the fate of pollutants, including radioactive and industrial wastes and pesticides, in this sensitive environment. It is proposed to develop and apply new means to address these issues by adapting methodologies for mapping geochemical tracer fields in real time using the submarine platform, in combination with more conventional chemical hydrography conducted from the ice upon surfacing with the sub. Specifically, a sea-going fiber optic UV spectrometer, will be mounted on the hull of the submarine. This instrument will continuously monitor the humic fraction of dissolved organic matter along track during the SCICEX-96 field season (August 1996) and monitor multiple parameters during the SCICEX-97 field season. In addition discreet samples will be taken via ice-based hydrocasts from the ice for calibration purposes and continuation of a related study to track Arctic river waters by geochemical means. This dataset will allow an unprecedented examination of the carbon cycle and circulation questions in the Arctic.