Journal of Physical Oceanography, submitted. Paper abstract bibtex
We present initial results from a year-long, high-resolution ($\sim$2 km) numerical simulation covering the east Greenland shelf and the Iceland and Irminger Seas. The model domain has been extended with respect to previous versions, and surface runoff and solid ice discharge from the Greenland Ice Sheet are now included. The model hydrography and circulation in the vicinity of Denmark Strait show good agreement with available observational datasets. We focus on the variability of the Denmark Strait Overflow (DSO) by detecting and characterizing boluses and pulses, which are the two dominant mesoscale features in the strait. On average, boluses (pulses) are 57.1 (27.5) hours long, occur every 3.2 (5.5) days, and are more frequent during summer (winter). Boluses (pulses) increase (decrease) the overflow cross-sectional area, and temperatures around the overflow interface are colder (warmer) by about 2.5°C (1.5°C). Boluses and pulses cross the strait with a slightly different orientation and in both cases the along-strait equatorward flow of dense water is enhanced, but more so for pulses. The cross-stream flow changes direction when these mesoscale features cross the strait and indicates that boluses are associated with veering of the horizontal current while pulses are characterized by backing. The lateral extent of the boluses is much greater than that of the pulses. Our results indicate that the mean southward volume flux of the DSO is about 30% greater in the presence of boluses and pulses. Thus, these features play a major role in controlling the variability of the DSO transport into the Irminger Sea.