Tips for choosing profile locations

To help you pick the locations of your profiles, here are a few resources.

EPSG:3031 Polar Stereographic map

Read x/y coordinates off this map to choose approximate start/end profile points.

import pygmt

fig = pygmt.Figure()
region = (-2700000, 2700000, -2700000, 2700000)
e, w, n, s = region
fig_height = 90  # in mm
fig_width = fig_height * (w - e) / (s - n)
fig_ratio = (s - n) / (fig_height / 1000)
fig_proj = "x1:" + str(fig_ratio)
fig_proj_ll = "s0/-90/-71/1:" + str(fig_ratio)

fig.coast(
    region=region, projection=fig_proj_ll, shorelines="0.5p,black", land="skyblue"
)
fig.coast(
    projection=fig_proj_ll, area_thresh="+ag", shorelines="0.5p,black", land="gray"
)

with pygmt.config(
    MAP_GRID_PEN_PRIMARY=".4p,dimgray", MAP_GRID_PEN_SECONDARY=".75p,black"
):
    fig.basemap(
        projection=fig_proj,
        frame=[
            "sxa500000g500000+a30+leasting (m)",
            "pxg250000",
            "sya500000g500000+lnorthing (m)",
            "pyg250000",
        ],
    )
fig.show()

coast [WARNING]: For a UTM or TM projection, your region -2700000/2700000/-2700000/2700000 is too large to be in degrees and thus assumed to be in meters
coast [WARNING]: For a UTM or TM projection, your region -2700000/2700000/-2700000/2700000 is too large to be in degrees and thus assumed to be in meters

Make custom shapefile in QGIS

QGIS, especially with the Quantarctica package, is an easy way to make a custom shapefile. This can then be used with antarctic_plots to sample data along the file.

To make the shapefile:

• Layer -> Create Layer -> New Shapefile Layer

• For Geometry Type, select Polygon

• Select EPSG:3031 for the coordinate reference system

• save to the same directory as your python file you want to work with.