Seminar Ozean, Eis, Atmosphäre
Seminar Ozean, Eis, Atmosphäre |
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Termin: 04.12.2001
Referent/in:
Olaf Klatt, iup-Bremen (Ozeanographie)
Title: Antarktis-Zirkulation
The sources and source strengths of ventilation of sub-surface layers in the
Weddell Sea are investigated. This includes the well known sources within the
Weddell Sea in front of the ice shelfs (Filchner-Ronne Ice Shelf ) and sources
located east of the Weddell Sea.
Ventilated sub-surface layers are characterized by CFC (Chlorofluorocarbons)
maxima. We make use of CFC-data collected all through the Weddell Gyre during
the period from 1984 to 1998. Layers with elevated CFC concentrations
("cores") were identified. The temporal evolution of the CFC concentration in
these cores were used to calculate age distributions of the water masses. In
addition, this analysis yields the fractions of young water (i.e. ventilated
water) of the water masses. CFC data in various cores were then used in
conjunction with current velocities obtained from current meters to calculate
CFC fluxes through the cores. From these the amount of ventilated surface
water contained in the cores were estimated. It shows that a substantial
portion of the ventilation of the Weddell Sea is brought about by sources from
outside.