, 2009). The iceberg output used as forcing is derived from a modified version of Bigg et al., 1996 and Bigg et al., 1997 iceberg model, developed by Martin and Adcroft (2010) and coupled to ORCA025, an eddy-permitting global implementation of the NEMO ocean model (Madec, 2008), to simulate the trajectories and melting of calved icebergs from Antarctica and Greenland in the presence Stem Cell Compound high throughput screening of mesoscale variability and fine-scale dynamical structure. Icebergs are treated as Lagrangian particles, with the distribution of icebergs by size derived from observations (see Bigg et al.,

1997 and Table 1). The momentum balance for icebergs comprises the Coriolis force, air and water form drags, the horizontal pressure gradient force, a wave radiation force, and interaction CX-4945 with sea ice. The mass balance for an individual iceberg is governed by bottom melting, buoyant convection at the side-walls and wave erosion (see Bigg et al., 1997). This configuration has been run for 14 years, and the associated freshwater fluxes used here are averages over years 10–14. Southern Hemisphere calving and melting rates are in near balance after 10 years, but further decades of simulation would be needed for global balance, due to slower equilibration of calving and melting in the Northern Hemisphere. An average pattern

of icebergs is our primary interest, which is why we settled for a relatively short integration time. For our purposes a detailed treatment of various mass loss processes is not necessary, because only the amount of freshwater release applied to the ocean is of interest. Nevertheless, the many different processes that affect the SMB

indicate that uncertainties are to be expected and distinction between mass loss processes and geographical locations needs to be made (Shepherd et al., 2012). The most obvious response Pembrolizumab mw to increased atmospheric temperatures is the melting of ice. This mass loss can be associated with adding freshwater directly offshore of the coast of the region where the melt takes place. We designate this freshwater source as run-off, or R for short. Run-off is contrasted with another form of mass loss that produces icebergs. The calving of icebergs from glaciers we call ice discharge, or D. The important difference is that icebergs are free floating chunks of ice and can drift to other locations and melt. This last observation prompts us to introduce the distinction between near (N) and far (F) freshwater forcing. A near forcing is always adjacent to the coast of origin and a far forcing is not restricted like this. The output of the iceberg drift and melt simulation gives us the location and relative magnitude of the far source of freshwater forcing. We assume spatial patterns on an annual cycle for these contributions, with magnitudes varying in time. The scaling factors are provided by the mass loss projections in the two polar regions.