variable (str) â choose which variable to load, either âw_bâ for basal melt rate, âw_b_interpâ,
for basal melt rate with interpolated values, and âw_b_uncertâ for uncertainty
Load a grid of basement topography.
Offshore and sub-Ross Ice Shelf basement topography.
from Tankersley et al.[2], Tankersley et al.[3] and
Lindeque et al.[4].
Elevations are referenced to WGS84 ellipsoid.
Parameters:
region (tuple[float, float, float, float], optional) â bounding region to clip the loaded grid to, by default doesnât clip
spacing (float, optional) â grid spacing to resample the loaded grid to, by default 5e3
registration (str, optional) â change registration with either âpâ for pixel or âgâ for gridline registration,
by default is None.
Referenced to the EIGEN-6C4 geoid. To convert to be ellipsoid-referenced, we add
the geoid grid. use reference=âellipsoidâ to include this conversion in the
fetch call.
Surface and ice thickness are in ice equivalents. Actual snow surface is from
REMA [6], and has had firn thickness added(?) to it to
get Bedmachine Surface.
To get snow surface: surface+firn
To get firn and ice thickness: thickness+firn
Here, icebase will return a grid of surface-thickness
This should be the same as snow-surface - (firn and ice thickness)
Parameters:
layer (str) â choose which layer to fetch:
âbedâ, âdataidâ, âerrbedâ, âfirnâ, âgeoidâ, âmappingâ, âmaskâ, âsourceâ,
âsurfaceâ, âthicknessâ; âicebaseâ will give results of surface-thickness
reference (str) â choose whether heights are referenced to âeigen-6c4â geoid or the
âellipsoidâ (WGS84), by default is eigen-6c4â
region (tuple[float, float, float, float], optional) â GMT-format region to clip the loaded grid to, by default doesnât clip
spacing (str or int, optional) â grid spacing to resample the loaded grid to, by default 500m
registration (str, optional) â change registration with either âpâ for pixel or âgâ for gridline registration,
by default is None.
kwargs (Any) â additional kwargs to pass to resample_grid
Returns:
Returns a loaded, and optional clip/resampled grid of Bedmachine.
All grids are by default referenced to the EIGEN-GL04C geoid. Use the
reference=âellipsoidâ to convert to the WGS-84 ellipsoid or reference=âeigen-6c4â to
convert to the EIGEN-6c4 geoid.
Unlike Bedmachine data, Bedmap2 surface and icethickness contain NaNâs over the
ocean, instead of 0âs. To fill these NaNâs with 0âs, set fill_nans=True.
Note, this only makes since if the reference is the geoid, therefore, if
reference=âellipsoid and fill_nans=True, the nanâs will be filled before
converting the results to the geoid (just for surface, since thickness isnât
relative to anything).
Parameters:
layer (str) â choose which layer to fetch:
âbedâ, âcoverageâ, âgrounded_bed_uncertaintyâ, âicemask_grounded_and_shelvesâ,
âlakemask_vostokâ, ârockmaskâ, âsurfaceâ, âthicknessâ,
âthickness_uncertainty_5kmâ, âgl04c_geiod_to_WGS84â, âicebaseâ,
âwater_thicknessâ
reference (str) â choose whether heights are referenced to the âeigen-6c4â geoid, the WGS84
ellipsoid, âellipsoidâ, or by default the âeigen-gl04câ geoid.
region (tuple[float, float, float, float], optional) â GMT-format region to clip the loaded grid to, by default doesnât clip
spacing (str or int, optional) â grid spacing to resample the loaded grid to, by default 10e3
registration (str, optional,) â choose between âgâ (gridline) or âpâ (pixel) registration types, by default is
the original type of the grid
fill_nans (bool, optional,) â choose whether to fill nans in âsurfaceâ and âthicknessâ with 0. If converting
to reference to the geoid, will fill nanâs before conversion, by default is
False
kwargs (Any) â additional kwargs to pass to resample_grid
Returns:
Returns a loaded, and optional clip/resampled grid of Bedmap2.
version=âan-2015â
Crustal thickness (distance from solid (ice and rock) top to Moho discontinuity)
from An et al.[11].
Accessed from http://www.seismolab.org/model/antarctica/lithosphere/index.html#an1s
File is the AN1-CRUST model, paper states âMoho depths and crustal thicknesses
referred to below are the distance from the solid surface to the Moho. We note that
this definition of Moho depth is different from that in the compilation of AN-MOHOâ.
Unclear, but seems moho depth is just negative of crustal thickness. Not sure if its
to the ice surface or ice base.
Parameters:
version (str) â Either âshen-2018â,
will add later: âlamb-2020â, âan-2015â, âbaranovâ, âchaputâ, âcrust1â,
âszwillusâ, âllubesâ, âpappaâ, âstalâ
region (tuple[float, float, float, float], optional) â GMT-format region to clip the loaded grid to, by default doesnât clip
spacing (int, optional) â grid spacing to resample the loaded grid to, by default spacing is read from
downloaded files
registration (str, optional) â change registration with either âpâ for pixel or âgâ for gridline registration,
by default is None.
Returns:
Returns a loaded, and optional clip/resampled grid of crustal thickness.
Loads a grid of Antarctic topography from ETOPO1 from ETOPO1 1 Arc-Minute Global Relief Model: Procedures, Data Sources and Analysis[14].
Originally at 10 arc-min resolution, reference to mean sea-level.
Loads a grid of Antarctic geoid heights derived from the EIGEN-6C4 from
Förste et al.[15] spherical harmonic model of Earthâs gravity field.
Originally at 10 arc-min resolution.
Negative values indicate the geoid is below the ellipsoid surface and vice-versa.
To convert a topographic grid which is referenced to the ellipsoid to be referenced
to the geoid, add this grid.
To convert a topographic grid which is referenced to the geoid to be reference to
the ellipsoid, subtract this grid.
version=âburton-johnson-2020â
From Burton-Johnson et al.[22].
Accessed from supplementary material
Choose for either of grid, or the point measurements
version=âlosing-ebbing-2021â
From Lösing and Ebbing[23] and Lösing and Ebbing[24].
version=âaq1â
From StÄl et al.[25] and StÄl et al.[26].
Parameters:
version (str) â Either âburton-johnson-2020â, âlosing-ebbing-2021â, âaq1â,
region (tuple[float, float, float, float], optional) â GMT-format region to clip the loaded grid to, by default doesnât clip
spacing (int, optional) â grid spacing to resample the loaded grid to, by default spacing is read from
downloaded files
registration (str, optional) â change registration with either âpâ for pixel or âgâ for gridline registration,
by default is None.
kwargs (Any) â if version=âburton-johnson-2020â, then kwargs are passed to return point
measurements instead of the grid.
Returns:
Returns a loaded, and optional clip/resampled grid of GHF data.
version=âantgg-updateâ
Preliminary compilation of Antarctica gravity and gravity gradient data.
Updates on 2016 AntGG compilation.
Accessed from https://ftp.space.dtu.dk/pub/RF/4D-ANTARCTICA/
version (str) â choose which version of gravity data to fetch.
region (tuple[float, float, float, float], optional) â GMT-format region to clip the loaded grid to, by default doesnât clip
spacing (str or int, optional) â grid spacing to resample the loaded grid to, by default 10e3
registration (str, optional) â change registration with either âpâ for pixel or âgâ for gridline registration,
by default is None.
kwargs (Any) â additional kwargs to pass to resample_grid and set the anomaly_type.
Keyword Arguments:
anomaly_type (str) â either âFAâ or âBAâ, for free-air and bouguer anomalies, respectively. For
antgg-update can also be âDGâ for gravity disturbance, or âErrâ for error
estimates.
Returns:
Returns a loaded, and optional clip/resampled grid of either observed, free-air
or Bouguer gravity anomalies.
Ice-sheet height and thickness changes from ICESat to ICESat-2.
from Smith et al.[41].
Choose a version of the data to download with the format: âais_VERSION_TYPEâ where
VERSION is âdhdtâ for total thickness change or âdmdtâ for corrected for firn-air
content.
TYPE is âfloatingâ or âgroundedâ
add â_filtâ to retrieve a filtered version of the data.
version (str,) â choose which file to retrieve from the following list:
âCoastlineâ, âBasins_Antarcticaâ, âBasins_IMBIEâ, âIceBoundariesâ, âIceShelfâ,
âMaskâ
Load the MODIS MoA imagery in either â750mâ or â125mâ resolutions from
MODIS Mosaic of Antarctica 2008-2009 (MOA2009) Image Map, Version 2[42] and Scambos et al.[43].
Load 1 of x âversionsâ of Antarctic Moho depth grids.
version=âshen-2018â
Depth to the Moho relative to the surface of solid earth (bottom of ice/ocean)
from Shen et al.[10].
Accessed from https://sites.google.com/view/weisen/research-products?authuser=0
Appears to be almost identical to crustal thickness from Shen et al. 2018
version=âan-2015â
This is fetch.crustal_thickness(version=âan-2015)* -1
Documentation is unclear whether the An crust model from
An et al.[11] is crustal thickness or moho depths, or whether it
makes a big enough difference to matter.
version=âpappa-2019â
from Pappa et al.[44].
Accessed from supplement material
Parameters:
version (str) â Either âshen-2018â, âan-2015â, âpappa-2019â,
will add later: âlamb-2020â, âbaranovâ, âchaputâ, âcrust1â,
âszwillusâ, âllubesâ,
region (tuple[float, float, float, float], optional) â GMT-format region to clip the loaded grid to, by default doesnât clip
spacing (int, optional) â grid spacing to resample the loaded grid to, by default spacing is read from
downloaded files
registration (str, optional,) â choose between âgâ (gridline) or âpâ (pixel) registration types, by default is
the original type of the grid
Returns:
Returns a loaded, and optional clip/resampled grid of crustal thickness.
Load the REMA surface elevation data from Howat et al.[6]. The data
are in EPSG3031 and reference to the WGS84 ellipsoid. To convert the data to be
geoid-referenced, subtract a geoid model, which you can get from fetch.geoid().
Choose between â1kmâ or â500mâ resolutions with parameter version.
Resample a grid to a new spacing, region, and/or registration. Method of resampling
depends on comparison with initial and supplied values for spacing, region, and
registration. If initial values not supplied, will try and extract them from the
grid.
Load either a shapefile of ROSETTA-ice flightlines, a dataframe of ROSETTA-Ice
airborne gravity data over the Ross Ice Shelf, or a dataframe of ROSETTA-Ice density
values from the density inversion.
from Tinto et al.[45].
Accessed from https://www.usap-dc.org/view/project/p0010035
This is only data from the first 2 of the 3 field seasons.
Columns:
Line Number: The ROSETTA-Ice survey line number, >1000 are tie lines
Latitude (degrees): Latitude decimal degrees WGS84
Longitude (degrees): Longitude decimal degrees WGS84
unixtime (seconds): The number of seconds that have elapsed since midnight
(00:00:00 UTC) on January 1st, 1970
Height (meters): Height above WGS84 ellipsoid
x (meters): Polar stereographic projected coordinates true to scale at 71° S
y (meters): Polar stereographic projected coordinates true to scale at 71° S
FAG_levelled (mGal): Levelled free air gravity
Load a dataframe of ROSETTA-Ice airborne magnetics data over the Ross Ice Shelf
from Tinto et al.[45].
Accessed from https://www.usap-dc.org/view/project/p0010035
Columns:
Line Number: The ROSETTA-Ice survey line number, >1000 are tie lines
Latitude (degrees): Latitude decimal degrees WGS84
Longitude (degrees): Longitude decimal degrees WGS84
unixtime (seconds): The number of seconds that have elapsed since midnight
(00:00:00 UTC) on January 1st, 1970
H_Ell (meters): Height above WGS84 ellipsoid
x (meters): Polar stereographic projected coordinates true to scale at 71° S
y (meters): Polar stereographic projected coordinates true to scale at 71° S
Mag_anomaly (nT): magnetic anomaly