def build_ocean_basins(gf, plot):
'''
Builds features defining the major ocean basins
Parameters
----------
gf : ``GeometricFeatures``
An object that knows how to download and read geometric featuers
plot : bool
Whether to plot each basin
Returns
-------
fc : ``FeatureCollection``
The new feature collection
'''
# Authors
# -------
# Xylar Asay-Davis
fc = FeatureCollection()
fc.set_group_name(groupName='OceanBasinRegionsGroup')
# build ocean basins from regions with the appropriate tags
for oceanName in [
'Atlantic', 'Pacific', 'Indian', 'Arctic', 'Southern_Ocean',
'Mediterranean'
]:
basinName = '{}_Basin'.format(oceanName)
print(oceanName)
print(' * merging features')
fcBasin = gf.read(componentName='ocean',
objectType='region',
tags=[basinName])
print(' * combining features')
fcBasin = fcBasin.combine(featureName=basinName)
fc.merge(fcBasin)
if plot:
fcBasin.plot(projection='cyl')
plt.title(oceanName)
# add the global ocean, global ocean between 65S and 65S, and
# equatorial region
fc.merge(
gf.read(componentName='ocean',
objectType='region',
featureNames=[
'Global Ocean', 'Global Ocean 65N to 65S',
'Global Ocean 15S to 15N'
]))
return fc
def build_MOC_basins(gf):
'''
Builds features defining the ocean basins used in computing the meridional
overturning circulation (MOC)
Parameters
----------
gf : ``GeometricFeatures``
An object that knows how to download and read geometric featuers
Returns
-------
fc : ``FeatureCollection``
The new feature collection
'''
# Authors
# -------
# Xylar Asay-Davis
MOCSubBasins = {
'Atlantic': ['Atlantic', 'Mediterranean'],
'IndoPacific': ['Pacific', 'Indian'],
'Pacific': ['Pacific'],
'Indian': ['Indian']
}
MOCSouthernBoundary = {
'Atlantic': '34S',
'IndoPacific': '34S',
'Pacific': '6S',
'Indian': '6S'
}
fc = FeatureCollection()
fc.set_group_name(groupName='MOCBasinRegionsGroup')
# build MOC basins from regions with the appropriate tags
for basinName in MOCSubBasins:
print('{} MOC'.format(basinName))
print(' * merging features')
tags = ['{}_Basin'.format(basin) for basin in MOCSubBasins[basinName]]
fcBasin = gf.read(componentName='ocean',
objectType='region',
tags=tags,
allTags=False)
print(' * combining features')
fcBasin = fcBasin.combine(featureName='{}_MOC'.format(basinName))
print(' * masking out features south of MOC region')
maskName = 'MOC mask {}'.format(MOCSouthernBoundary[basinName])
fcMask = gf.read(componentName='ocean',
objectType='region',
featureNames=[maskName])
# mask out the region covered by the mask
fcBasin = fcBasin.difference(fcMask)
# remove various small polygons that are not part of the main MOC
# basin shapes. Most are tiny but one below Australia is about 20
# deg^2, so make the threshold 100 deg^2 to be on the safe side.
fcBasin = remove_small_polygons(fcBasin, minArea=100.)
# add this basin to the full feature collection
fc.merge(fcBasin)
return fc