Add ISMIP6 Antarctic ocean regions

feature_creation_scripts/ismip6_antarctic_ocean_regions/README.md

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+# ISMIP6 Antarctic Ocean Regions
+
+Features used to compute regional and temporal mean temperature and salinity
+for comparison with the model selection process in 
+[Barthel et al. (2020)](https://doi.org/10.5194/tc-14-855-2020), which was
+ used to select CMIP5 models for 
+ [ISMIP6](http://www.climate-cryosphere.org/mips/ismip6).

feature_creation_scripts/ismip6_antarctic_ocean_regions/ismip6_antarctic_ocean_regions.py

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+#!/usr/bin/env python
+
+import shapely.geometry
+import shapely.ops
+import numpy
+import xarray
+import os
+import matplotlib.pyplot as plt
+import pyproj
+import zipfile
+import shutil
+
+from geometric_features import GeometricFeatures, FeatureCollection
+from geometric_features.feature_collection import _round_coords
+
+from geometric_features.download import download_files
+from geometric_features.utils import write_feature_names_and_tags
+
+
+def bedmap2_bin_to_netcdf(outFileName):
+
+    if os.path.exists(outFileName):
+        return
+
+    fields = ['bed', 'surface', 'thickness', 'coverage', 'rockmask',
+              'grounded_bed_uncertainty', 'icemask_grounded_and_shelves']
+
+    allExist = True
+    for field in fields:
+        fileName = 'bedmap2/bedmap2_bin/bedmap2_{}.flt'.format(field)
+        if not os.path.exists(fileName):
+            allExist = False
+            break
+
+    if not allExist:
+        # download
+        baseURL = 'https://secure.antarctica.ac.uk/data/bedmap2'
+        fileNames = ['bedmap2_bin.zip']
+
+        download_files(fileNames, baseURL, 'bedmap2')
+
+        print('Decompressing Bedmap2 data...')
+        # unzip
+        with zipfile.ZipFile('bedmap2/bedmap2_bin.zip', 'r') as f:
+            f.extractall('bedmap2/')
+        print('  Done.')
+
+    print('Converting Bedmap2 to NetCDF...')
+    ds = xarray.Dataset()
+    x = numpy.linspace(-3333000., 3333000., 6667)
+    y = x
+    ds['x'] = ('x', x)
+    ds.x.attrs['units'] = 'meters'
+    ds['y'] = ('y', y)
+    ds.y.attrs['units'] = 'meters'
+    ds.attrs['Grid'] = "Datum = WGS84, earth_radius = 6378137., " \
+                       "earth_eccentricity = 0.081819190842621, " \
+                       "falseeasting = -3333000., " \
+                       "falsenorthing = -3333000., " \
+                       "standard_parallel = -71., central_meridien = 0, " \
+                       "EPSG=3031"
+    ds.attrs['proj'] = "+proj=stere +lat_0=-90 +lat_ts=-71 +lon_0=0 +k=1 " \
+                       "+x_0=0 +y_0=0 +datum=WGS84 +units=m +no_defs"
+    ds.attrs['proj4'] = "+init=epsg:3031"
+
+    # Antarctic stereographic
+    inProj = pyproj.Proj(init='epsg:3031')
+    # lon/lat
+    outProj = pyproj.Proj(init='epsg:4326')
+    X, Y = numpy.meshgrid(x, y)
+    Lon, Lat = pyproj.transform(inProj, outProj, X, Y)
+
+    ds['lon'] = (('y', 'x'), Lon)
+    ds.lon.attrs['units'] = 'degrees east'
+    ds['lat'] = (('y', 'x'), Lat)
+    ds.lat.attrs['units'] = 'degrees north'
+
+    # add Bedmap2 data
+    for fieldName in fields:
+        fileName = 'bedmap2/bedmap2_bin/bedmap2_{}.flt'.format(fieldName)
+        with open(fileName, 'r') as f:
+            field = numpy.fromfile(f, dtype=numpy.float32).reshape(6667, 6667)
+            # flip the y axis
+            field = field[::-1, :]
+            # switch invalid values to be NaN (as expected by xarray)
+            field[field == -9999.] = numpy.nan
+        if fieldName == 'rockmask':
+            # rock mask is zero where rock and -9999 (now NaN) elsewhere
+            field = numpy.array(numpy.isfinite(field), numpy.float32)
+        if fieldName == 'icemask_grounded_and_shelves':
+            # split into separate grounded and floating masks
+            ds['icemask_grounded'] = \
+                (('y', 'x'), numpy.array(field == 0, numpy.float32))
+            ds['icemask_shelves'] = \
+                (('y', 'x'), numpy.array(field == 1, numpy.float32))
+            ds['open_ocean_mask'] = \
+                (('y', 'x'), numpy.array(numpy.isnan(field), numpy.float32))
+        else:
+            ds[fieldName] = (('y', 'x'), field)
+
+    ds.to_netcdf(outFileName)
+    print('  Done.')
+
+
+def get_longest_contour(contourValue, author):
+
+    def stereo_to_lon_lat(x, y):
+        return pyproj.transform(inProj, outProj, x, y)
+
+    ds = xarray.open_dataset('bedmap2.nc')
+
+    # plot contours
+    plt.figure()
+    cs = plt.contour(ds.x.values, ds.y.values, ds.bed, (contourValue,))
+    paths = cs.collections[0].get_paths()
+
+    pathLengths = [len(paths[i]) for i in range(len(paths))]
+    iLongest = numpy.argmax(pathLengths)
+
+    p = paths[iLongest]
+    v = p.vertices
+    x = v[:, 0]
+    y = v[:, 1]
+
+    # Antarctic stereographic
+    inProj = pyproj.Proj(init='epsg:3031')
+    # lon/lat
+    outProj = pyproj.Proj(init='epsg:4326')
+
+    poly = shapely.geometry.Polygon([(i[0], i[1]) for i in zip(x, y)])
+
+    epsilon = 1e-14
+    minY = numpy.amin(y)
+    wedge = shapely.geometry.Polygon([(epsilon, minY),
+                                      (epsilon**2, -epsilon),
+                                      (0, epsilon),
+                                      (-epsilon**2, -epsilon),
+                                      (-epsilon, minY),
+                                      (epsilon, minY)])
+
+    difference = poly.difference(wedge)
+
+    difference = shapely.ops.transform(stereo_to_lon_lat, difference)
+
+    fc = FeatureCollection()
+
+    geometry = shapely.geometry.mapping(difference)
+    # get rid of the wedge again by rounding the coordinates
+    geometry['coordinates'] = _round_coords(geometry['coordinates'])
+
+    fc.add_feature(
+        {"type": "Feature",
+         "properties": {"name": "Contour {}".format(contourValue),
+                        "author": author,
+                        "object": 'region',
+                        "component": 'ocean'},
+         "geometry": geometry})
+
+    return fc
+
+
+def make_polygon(lons, lats, name, author, tags):
+    fc = FeatureCollection()
+
+    coords = list()
+    for index in range(len(lons)):
+        coords.append([lons[index], lats[index]])
+    coords.append([lons[0], lats[0]])
+
+    fc.add_feature(
+        {"type": "Feature",
+         "properties": {"name": name,
+                        "author": author,
+                        "object": 'region',
+                        "component": 'ocean',
+                        "tags": tags,
+                        "zmin": -1500.,
+                        "zmax": -200.},
+         "geometry": {
+             "type": "Polygon",
+             "coordinates": [coords]}})
+    return fc
+
+
+def shelf_polygon(lons, lats, name, author, tags, fcContour):
+    fc = make_polygon(lons, lats, name, author, tags)
+
+    lons = [-180., -180., 180., 180.]
+    lats = [-90., 90., 90., -90.]
+    fc_world = make_polygon(lons, lats, name, author, tags)
+
+    fcContour = fc_world.difference(fcContour)
+
+    fcShelf = fc.difference(fcContour)
+
+    props = fcShelf.features[0]['properties']
+    props['name'] = props['name'] + ' Shelf'
+    props['tags'] = props['tags'] + ';Shelf'
+    props['zmin'] = -1500.
+    props['zmax'] = -200.
+
+    return fcShelf
+
+
+def main():
+    author = 'Xylar Asay-Davis, Alice Barthel, Nicolas Jourdain'
+    tags = 'Antarctic;ISMIP6'
+
+    # make a geometric features object that knows about the geometric data
+    # cache up a couple of directories
+    gf = GeometricFeatures('../../geometric_data')
+
+    bedmap2_bin_to_netcdf('bedmap2.nc')
+
+    fcContour1500 = get_longest_contour(contourValue=-1500., author=author)
+
+    fc = FeatureCollection()
+
+    lons = [-65., -25., -25., -65.]
+    lats = [-80., -80., -77., -71.]
+    fc.merge(shelf_polygon(
+        lons, lats,  name='ISMIP6 Weddell Sea', author=author, tags=tags,
+        fcContour=fcContour1500))
+
+    lons = [-128., -128., -90., -90.]
+    lats = [-76., -69., -69., -76.]
+    fc.merge(shelf_polygon(
+        lons, lats, name='ISMIP6 Amundsen Sea', author=author, tags=tags,
+        fcContour=fcContour1500))
+
+    lons = [45., 45., 90., 90.]
+    lats = [-70., -60., -60., -70.]
+    fc.merge(shelf_polygon(
+        lons, lats, name='ISMIP6 Amery Sector', author=author, tags=tags,
+        fcContour=fcContour1500))
+
+    lons = [-22.5, -22.5, 22.5, 22.5]
+    lats = [-75., -65., -65., -75.]
+    fc.merge(shelf_polygon(
+        lons, lats, name='ISMIP6 Dronning Maud Land', author=author, tags=tags,
+        fcContour=fcContour1500))
+
+    lons = [110., 110., 130., 130.]
+    lats = [-70., -60., -60., -70.]
+    fc.merge(shelf_polygon(
+        lons, lats, name='ISMIP6 Totten Region', author=author, tags=tags,
+        fcContour=fcContour1500))
+
+    lons = [165., 165., 180., 180.]
+    lats = [-80., -71., -73., -80.]
+    fc_ross = shelf_polygon(
+        lons, lats, name='ISMIP6 Western Ross Sea', author=author, tags=tags,
+        fcContour=fcContour1500)
+
+    lons = [-180., -180., -150., -150.]
+    lats = [-80., -73., -77., -80.]
+    fc_ross.merge(shelf_polygon(
+        lons, lats, name='ISMIP6 Eastern Ross Sea', author=author, tags=tags,
+        fcContour=fcContour1500))
+
+    old_props = fc_ross.features[0]['properties']
+    fc_ross = fc_ross.combine('ISMIP6 Ross Sea')
+    props = fc_ross.features[0]['properties']
+    for prop in ['tags', 'zmin', 'zmax']:
+        props[prop] = old_props[prop]
+
+    fc.merge(fc_ross)
+
+    fc.plot(projection='southpole')
+    fc.to_geojson('ismip6_antarctic_ocean_regions.geojson')
+
+    # "split" these features into individual files in the geometric data cache
+    gf.split(fc)
+
+    # update the database of feature names and tags
+    write_feature_names_and_tags(gf.cacheLocation)
+    # move the resulting file into place
+    shutil.copyfile('features_and_tags.json',
+                    '../../geometric_features/features_and_tags.json')
+
+    plt.show()
+
+
+if __name__ == '__main__':
+    main()