tinput-data.rst - pism - [fork] customized build of PISM, the parallel ice sheet model (tillflux branch)
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tinput-data.rst (1779B)
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1 .. include:: ../../global.txt
2
3 Input data
4 ----------
5
6 The NetCDF data used to initialize SeaRISE runs is `freely-available online
7 <searise-greenland_>`_.
8
9 To download the specific file we want, namely ``Greenland_5km_v1.1.nc``, and preprocess it
10 for PISM, do:
11
12 .. code-block:: none
13
14 cd examples/std-greenland
15 ./preprocess.sh
16
17 The script ``preprocess.sh`` requires ``wget`` and also the `NetCDF Operators <NCO_>`_. It
18 downloads the version 1.1 of the SeaRISE "master" present-day data set, which contains ice
19 thickness and bedrock topography from BEDMAP :cite:`BamberLayberryGogenini`, and modeled
20 precipitation and surface mass balance rates from RACMO :cite:`Ettemaetal2009`, among
21 other fields.
22
23 In particular, it creates three new NetCDF files which can be read by PISM. The
24 spatially-varying fields, with adjusted metadata, go in ``pism_Greenland_5km_v1.1.nc``.
25 The other two new files contain famous time-dependent paleo-climate records from ice and
26 seabed cores: ``pism_dT.nc`` has the GRIP temperature record :cite:`JohnsenetalGRIP` and
27 ``pism_dSL.nc`` has the SPECMAP sea level record :cite:`Imbrieetal1984`.
28
29 Any of these NetCDF files can be viewed with ``ncview`` or other NetCDF visualization
30 tools; see :numref:`tab-NetCDFview`. An application of IDV to the master data set produced
31 :numref:`fig-sr-input`, for example. Use ``ncdump -h`` to see the metadata and history of
32 the files.
33
34 .. figure:: figures/sr-greenland-input.png
35 :name: fig-sr-input
36
37 The input file contains present-day ice thickness (left; m), bedrock elevation (center;
38 m), and present-day precipitation (right; `m / year` ice equivalent) for
39 SeaRISE-Greenland. These are fields :var:`thk`, :var:`topg`, and :var:`precipitation`,
40 respectively, in ``pism_Greenland_5km_v1.1.nc``.