.. _task_geojsonTransects:
geojsonTransects
================
An analysis task for interpolating MPAS fields to transects specified by files
in ``geojson`` format..
Component and Tags::
component: ocean
tags: climatology, transect, geojson
Configuration Options
---------------------
The following configuration options are available for this task::
[geojsonTransects]
## options related to plotting model transects at points determined by a
## geojson file. To generate your own geojson file, go to:
## http://geojson.io/
## and draw one or more polylines, then add a name to each:
##
## "properties": {
## "name": "My Favorite Name"
## },
## and save the file as GeoJSON (say transects.geojson). Finally, set the
## option:
## geojsonFiles = ['transects.geojson']
## (giving an absolute path if necessary) in your custom config file.
# a list of geojson files containing lat/lon points in LineStrings to be
# plotted. If relative paths are given, they are relative to the current
# working directory. The files must be listed in quotes, e.g.:
# geojsonFiles = ['file1.geojson', '/path/to/file2.geojson']
geojsonFiles = []
# a list of dictionaries for each field to plot. The dictionary includes
# prefix (used for file names, task names and sections) as well as the mpas
# name of the field, units for colorbars and a the name as it should appear
# in figure titles and captions.
fields =
[{'prefix': 'temperature',
'mpas': 'timeMonthly_avg_activeTracers_temperature',
'units': r'$\degree$C',
'titleName': 'Potential Temperature'},
{'prefix': 'salinity',
'mpas': 'timeMonthly_avg_activeTracers_salinity',
'units': r'PSU',
'titleName': 'Salinity'},
{'prefix': 'potentialDensity',
'mpas': 'timeMonthly_avg_potentialDensity',
'units': r'kg m$^{-3}$',
'titleName': 'Potential Density'},
{'prefix': 'zonalVelocity',
'mpas': 'timeMonthly_avg_velocityZonal',
'units': r'm s$^{-1}$',
'titleName': 'Zonal Velocity'},
{'prefix': 'meridionalVelocity',
'mpas': 'timeMonthly_avg_velocityMeridional',
'units': r'm s$^{-1}$',
'titleName': 'Meridional Velocity'}]
# Times for comparison times (Jan, Feb, Mar, Apr, May, Jun, Jul, Aug, Sep, Oct,
# Nov, Dec, JFM, AMJ, JAS, OND, ANN)
seasons = ['ANN']
# The approximate horizontal resolution (in km) of each transect. Latitude/
# longitude between observation points will be subsampled at this interval.
# Use 'obs' to indicate no subsampling.
horizontalResolution = 5
# The name of the vertical comparison grid. Valid values are 'mpas' for the
# MPAS vertical grid or any other name if the vertical grid is defined by
# 'verticalComparisonGrid'
#verticalComparisonGridName = mpas
verticalComparisonGridName = uniform_0_to_4000m_at_10m
# The vertical comparison grid if 'verticalComparisonGridName' is not 'mpas'.
# This should be numpy array of (typically negative) elevations (in m).
verticalComparisonGrid = numpy.linspace(0, -4000, 401)
# The minimum weight of a destination cell after remapping. Any cell with
# weights lower than this threshold will therefore be masked out.
renormalizationThreshold = 0.01
[geojsonTemperatureTransects]
## options related to plotting geojson transects of potential temperature
# colormap for model/observations
colormapNameResult = RdYlBu_r
# the type of norm used in the colormap
normTypeResult = linear
# A dictionary with keywords for the SemiLogNorm
normArgsResult = {'vmin': -2., 'vmax': 30.}
# place the ticks automatically by default
# colorbarTicksResult = numpy.linspace(-2., 2., 9)
# colormap for differences
colormapNameDifference = balance
# the type of norm used in the colormap
normTypeDifference = linear
# A dictionary with keywords for the SemiLogNorm
normArgsDifference = {'vmin': -2., 'vmax': 2.}
# place the ticks automatically by default
# colorbarTicksDifference = numpy.linspace(-2., 2., 9)
[geojsonSalinityTransects]
## options related to plotting geojson transects of salinity
# colormap for model/observations
colormapNameResult = haline
# the type of norm used in the colormap
normTypeResult = linear
# A dictionary with keywords for the SemiLogNorm
normArgsResult = {'vmin': 30, 'vmax': 39.0}
# place the ticks automatically by default
# colorbarTicksResult = numpy.linspace(34.2, 35.2, 9)
# colormap for differences
colormapNameDifference = balance
# the type of norm used in the colormap
normTypeDifference = linear
# A dictionary with keywords for the SemiLogNorm
normArgsDifference = {'vmin': -0.5, 'vmax': 0.5}
# place the ticks automatically by default
# colorbarTicksDifference = numpy.linspace(-0.5, 0.5, 9)
[geojsonPotentialDensityTransects]
## options related to plotting geojson transects of potential density
# colormap for model/observations
colormapNameResult = Spectral_r
# the type of norm used in the colormap
normTypeResult = linear
# A dictionary with keywords for the norm
normArgsResult = {'vmin': 1026.5, 'vmax': 1028.}
# place the ticks automatically by default
# colorbarTicksResult = numpy.linspace(1026., 1028., 9)
# colormap for differences
colormapNameDifference = balance
# the type of norm used in the colormap
normTypeDifference = linear
# A dictionary with keywords for the norm
normArgsDifference = {'vmin': -0.3, 'vmax': 0.3}
# place the ticks automatically by default
# colorbarTicksDifference = numpy.linspace(-0.3, 0.3, 9)
[geojsonZonalVelocityTransects]
## options related to plotting geojson transects of zonal velocity
# colormap for model/observations
colormapNameResult = delta
# color indices into colormapName for filled contours
# the type of norm used in the colormap
normTypeResult = linear
# A dictionary with keywords for the norm
normArgsResult = {'vmin': -0.2, 'vmax': 0.2}
# determine the ticks automatically by default, uncomment to specify
# colorbarTicksResult = numpy.linspace(-0.2, 0.2, 9)
# colormap for differences
colormapNameDifference = balance
# the type of norm used in the colormap
normTypeDifference = linear
# A dictionary with keywords for the norm
normArgsDifference = {'vmin': -0.2, 'vmax': 0.2}
# determine the ticks automatically by default, uncomment to specify
# colorbarTicksDifference = numpy.linspace(-0.2, 0.2, 9)
[geojsonMeridionalVelocityTransects]
## options related to plotting geojson transects of meridional velocity
# colormap for model/observations
colormapNameResult = delta
# color indices into colormapName for filled contours
# the type of norm used in the colormap
normTypeResult = linear
# A dictionary with keywords for the norm
normArgsResult = {'vmin': -0.2, 'vmax': 0.2}
# determine the ticks automatically by default, uncomment to specify
# colorbarTicksResult = numpy.linspace(-0.2, 0.2, 9)
# colormap for differences
colormapNameDifference = balance
# the type of norm used in the colormap
normTypeDifference = linear
# A dictionary with keywords for the norm
normArgsDifference = {'vmin': -0.2, 'vmax': 0.2}
# determine the ticks automatically by default, uncomment to specify
# colorbarTicksDifference = numpy.linspace(-0.2, 0.2, 9)
Geojson Files
-------------
This task takes a list of geojson file names (supplied as a python list of
``str``::
geojsonFiles = ['file1.geojson', '/path/to/file2.geojson']
Transects are specified by ``LineString`` objects in the files. Some examples
are provided in the `MPAS geometric features repository`_. You can also
generate your own very easily at To generate your own geojson file, go to
`geojson.io`_ and draw one or more polylines, then add a name to each::
...
"properties": {
"name": "My Favorite Name"
},
...
and save the file as GeoJSON (say transects.geojson). Finally, set the
option::
geojsonFiles = ['transects.geojson']
(giving an absolute path if necessary) in your custom config file.
Fields
------
Since there are no observations associated with geojson transects, you are
free to choose which MPAS fields you would like to plot. These fields are
provided as a python dictionary. The keys are names for the fields (anything
you would like use as a prefix on files and subtask names, best if it does
not contain spaces). The values are python dictionaries. The values
associate with the ``mpas`` key are the names of the 3D fields where transects
are desired. The ``units`` entry indicates the units to display on the
colorbar. The ``titleName`` entry specifies the name of the field to include
in plot titles and captions.
Each field must have a corresponding section in the config file defining its
color maps. For example, ``temperature`` has an associated
``[geojsonTemperatureTransect]`` section.
Other Options
-------------
For details on the remaining configuration options, see:
* :ref:`config_transects`
* :ref:`config_remapping`
* :ref:`config_colormaps`
* :ref:`config_seasons`
Example Result
--------------
.. image:: examples/geojson_transect.png
:width: 500 px
:align: center
.. _`MPAS geometric features repository`: https://github.com/MPAS-Dev/geometric_features
.. _`geojson.io`: http://geojson.io/