pkg/icefront/icefront_description.tex

5da8ce63fa Dimi*0001 %%
                0002 %%
                0003
                0004 Package ``ICEFRONT'' is an extension of pkg/shelfice that deals with vertical
ee2b5232f9 Yun *0005 ice fronts for application to tidewater glaciers.
                0006 (Xu et al., Numerical experiments on subaqueous melting of Greenland tidewater
                0007  glaciers in response to ocean warming and enhanced subglacial discharge.
                0008  Annals of Glaciology, 2012. http://ecco2.org/manuscripts/2012/Xu2012.pdf)
5da8ce63fa Dimi*0009
ee2b5232f9 Yun *0010 It includes
5da8ce63fa Dimi*0011
ee2b5232f9 Yun *0012 1) a routine (icefront_init_fixed.F), which loads two 2-D variables:
                0013   a) R_icefront: depth of the submerged vertical ice wall in or at the edge of
                0014      each wet grid of points
                0015   b) icefrontlength: ratio of the horizontal length of vertical ice front to
                0016      horizontal grid area for points in a)
5da8ce63fa Dimi*0017
ee2b5232f9 Yun *0018 2) a routine (icefront_thermodynamics.F) similar to shelfice_thermodynamics
                0019    which applies the ice shelf melt/freeze equations to horizontal locations
                0020    with vertical ice wall, i.e., containing non-zero values for 1a) and 1b).
                0021
                0022 3) a routine (icefront_tendency_apply.F) which applies the forcing computed
                0023    in 2) to grids of ice wall.
5da8ce63fa Dimi*0024
                0025 The package can be used in conjunction with pkg/shelfice, if both the
                0026 horizontal and vertical termini of glaciers need to be represented, or it can
                0027 be used on its own, if the glaciers terminate and calve near the grounding
                0028 line, i.e., if they have no significant ice shelf cavity beneath them.
                0029
                0030 Pkg/icefront is separated from pkg/shelfice because
                0031
                0032 (i) rather than search 2D space for ice shelf cavities, the icefront package
                0033 needs to search a 3D space for the ice fronts,
                0034
ee2b5232f9 Yun *0035 (ii) each grid box can have up to three separate contributions from ice
                0036 fronts while ice shelf cavities only have one contribution from the top, and
5da8ce63fa Dimi*0037
ee2b5232f9 Yun *0038 (iii) eventually the physics of the two packages may diverge to include
5da8ce63fa Dimi*0039 different processes, for example, a fancier boundary layer scheme for shelfice
ee2b5232f9 Yun *0040 and a calving scheme for icefront.
5da8ce63fa Dimi*0041
ee2b5232f9 Yun *0042 Pkg/icefront is mostly designed to represent Greenland or Alaska tidewater
                0043 glaciers in model configurations that can resolve the fjords and glacier outlets,
5da8ce63fa Dimi*0044 i.e., that have horizontal grid spacing of O(1km) or less.
ee2b5232f9 Yun *0045
                0046 Verification experiment for pkg/icefront is verification/isomip/input.icefront/