An isotope modelling study of a Heinrich Event : evaluation of the iceberg discharge volume and duration
Abstract
Using a coupled climate model of intermediate complexity, CLIMBER-2, we have computed the time and space distribution of the water isotopic anomaly (delta 18O) during a Heinrich event in the North Atlantic, using many different scenarios for the volume and the duration of this event. The resulting calcium carbonate delta18O fields are then computed and compared to the available isotopic data, from planktonic foraminifera, for this particular event. When considering a single freshwater pulse event, only the short duration scenarios, of the order of centuries, are consistent with the data, and the iceberg volume involved is accordingly in the lower range of previous estimates. A longer, millenial-scale Heinrich event, involving larger amounts of icebergs, is therefore only possible if it is composed of several well defined shorter duration freshwater pulses. Such composed events are also investigated and estimations of the total ice volume involved will be suggested.
- Publication:
-
EGS - AGU - EUG Joint Assembly
- Pub Date:
- April 2003
- Bibcode:
- 2003EAEJA.....5077R