Add min and max thresholds for plotting fields

Use these to mask sea-ice concentration (with a default min
threshold of 0.15) and sea-ice thickness (with a minimum of zero).

mpas_analysis/default.cfg

@@ -3662,6 +3662,9 @@ observationPrefixes = ['NASATeam', 'Bootstrap']
 # arrange subplots vertically?
 vertical = False
 
+# the minimum threshold below which concentration is masked out
+minConcentration = 0.15
+
 # observations files
 concentrationNASATeamNH_JFM = SSMI/NASATeam_NSIDC0051/SSMI_NASATeam_gridded_concentration_NH_jfm.interp0.5x0.5_20180710.nc
 concentrationNASATeamNH_JAS = SSMI/NASATeam_NSIDC0051/SSMI_NASATeam_gridded_concentration_NH_jas.interp0.5x0.5_20180710.nc
@@ -3705,6 +3708,9 @@ observationPrefixes = ['NASATeam', 'Bootstrap']
 # arrange subplots vertically?
 vertical = False
 
+# the minimum threshold below which concentration is masked out
+minConcentration = 0.15
+
 # observations files
 concentrationNASATeamSH_DJF = SSMI/NASATeam_NSIDC0051/SSMI_NASATeam_gridded_concentration_SH_djf.interp0.5x0.5_20180710.nc
 concentrationNASATeamSH_JJA = SSMI/NASATeam_NSIDC0051/SSMI_NASATeam_gridded_concentration_SH_jja.interp0.5x0.5_20180710.nc

mpas_analysis/sea_ice/climatology_map_sea_ice_conc.py

@@ -112,8 +112,7 @@ def __init__(self, config, mpasClimatologyTask, hemisphere,
         else:
             self._add_ref_tasks(seasons, comparisonGridNames, hemisphere,
                                 hemisphereLong, remapClimatologySubtask,
-                                controlConfig, mpasFieldName,
-                                fieldName, iselValues)
+                                controlConfig, mpasFieldName)
 
     def _add_obs_tasks(self, seasons, comparisonGridNames, hemisphere,
                        hemisphereLong, remapClimatologySubtask,
@@ -122,6 +121,8 @@ def _add_obs_tasks(self, seasons, comparisonGridNames, hemisphere,
         obsFieldName = 'seaIceConc'
         sectionName = self.taskName
 
+        minConcentration = config.getfloat(self.taskName, 'minConcentration')
+
         observationPrefixes = config.getexpression(sectionName,
                                                    'observationPrefixes')
         for prefix in observationPrefixes:
@@ -181,15 +182,17 @@ def _add_obs_tasks(self, seasons, comparisonGridNames, hemisphere,
                         groupSubtitle=None,
                         groupLink='{}_conc'.format(hemisphere.lower()),
                         galleryName='Observations: SSM/I {}'.format(
-                            prefix))
+                            prefix),
+                        maskMinThreshold=minConcentration)
 
                     self.add_subtask(subtask)
 
     def _add_ref_tasks(self, seasons, comparisonGridNames, hemisphere,
                        hemisphereLong, remapClimatologySubtask,
-                       controlConfig, mpasFieldName, fieldName,
-                       iselValues):
+                       controlConfig, mpasFieldName):
 
+        minConcentration = self.config.getfloat(self.taskName,
+                                                'minConcentration')
         controlRunName = controlConfig.get('runs', 'mainRunName')
         galleryName = None
         refTitleLabel = 'Control: {}'.format(controlRunName)
@@ -224,7 +227,8 @@ def _add_ref_tasks(self, seasons, comparisonGridNames, hemisphere,
                     galleryGroup=galleryGroup,
                     groupSubtitle=None,
                     groupLink='{}_conc'.format(hemisphere.lower()),
-                    galleryName=galleryName)
+                    galleryName=galleryName,
+                    maskMinThreshold=minConcentration)
 
                 self.add_subtask(subtask)
 

mpas_analysis/sea_ice/climatology_map_sea_ice_thick.py

@@ -164,7 +164,7 @@ def __init__(self, config, mpasClimatologyTask, hemisphere,
                     groupSubtitle=None,
                     groupLink=f'{hemisphere.lower()}_thick',
                     galleryName=galleryName,
-                    maskValue=0)
+                    maskMinThreshold=0)
 
                 self.add_subtask(subtask)
 

mpas_analysis/shared/plot/plot_climatology_map_subtask.py

@@ -97,8 +97,11 @@ class PlotClimatologyMapSubtask(AnalysisTask):
     configSectionName : str
         the name of the section where the color map and range is defined
 
-    maskValue : float or None
-        a value to mask out in plots
+    maskMinThreshold : float or None
+        a value below which the field is mask out in plots
+
+    maskMaxThreshold : float or None
+        a value above which the field is mask out in plots
     """
 
     def __init__(self, parentTask, season, comparisonGridName,
@@ -209,13 +212,15 @@ def __init__(self, parentTask, season, comparisonGridName,
         self.startDate = None
         self.endDate = None
         self.filePrefix = None
-        self.maskValue = None
+        self.maskMinThreshold = None
+        self.maskMaxThreshold = None
 
     def set_plot_info(self, outFileLabel, fieldNameInTitle, mpasFieldName,
                       refFieldName, refTitleLabel, unitsLabel,
                       imageCaption, galleryGroup, groupSubtitle, groupLink,
                       galleryName, diffTitleLabel='Model - Observations',
-                      configSectionName=None, maskValue=None):
+                      configSectionName=None, maskMinThreshold=None,
+                      maskMaxThreshold=None):
         """
         Store attributes related to plots, plot file names and HTML output.
 
@@ -264,8 +269,11 @@ def set_plot_info(self, outFileLabel, fieldNameInTitle, mpasFieldName,
             the name of the section where the color map and range is defined,
             default is the name of the task
 
-        maskValue : float or None, optional
-            a value to mask out in plots
+        maskMinThreshold : float or None, optional
+            a value below which the field is mask out in plots
+
+        maskMaxThreshold : float or None, optional
+            a value above which the field is mask out in plots
         """
 
         self.outFileLabel = outFileLabel
@@ -282,7 +290,8 @@ def set_plot_info(self, outFileLabel, fieldNameInTitle, mpasFieldName,
         self.groupSubtitle = groupSubtitle
         self.groupLink = groupLink
         self.galleryName = galleryName
-        self.maskValue = maskValue
+        self.maskMinThreshold = maskMinThreshold
+        self.maskMaxThreshold = maskMaxThreshold
 
         if configSectionName is None:
             self.configSectionName = self.taskName
@@ -486,18 +495,10 @@ def _plot_latlon(self, remappedModelClimatology, remappedRefClimatology,
 
             bias = modelOutput - refOutput
 
-            # mask with maskValue only after taking the diff
-            if self.maskValue is not None:
-                mask = np.logical_or(refOutput.mask,
-                                     refOutput == self.maskValue)
-                refOutput = np.ma.masked_array(refOutput, mask)
-                bias = np.ma.masked_array(bias, mask)
-
-        # mask with maskValue only after taking the diff
-        if self.maskValue is not None:
-            mask = np.logical_or(modelOutput.mask,
-                                 modelOutput == self.maskValue)
-            modelOutput = np.ma.masked_array(modelOutput, mask)
+            # mask with thresholds only after taking the diff
+            refOutput = self._mask_with_thresholds(refOutput)
+
+        modelOutput = self._mask_with_thresholds(modelOutput)
 
         if config.has_option(configSectionName, 'titleFontSize'):
             titleFontSize = config.getint(configSectionName, 'titleFontSize')
@@ -574,17 +575,9 @@ def _plot_projection(self, remappedModelClimatology,
             bias = modelOutput - refOutput
 
             # mask with maskValue only after taking the diff
-            if self.maskValue is not None:
-                mask = np.logical_or(refOutput.mask,
-                                     refOutput == self.maskValue)
-                refOutput = np.ma.masked_array(refOutput, mask)
-                bias = np.ma.masked_array(bias, mask)
-
-        # mask with maskValue only after taking the diff
-        if self.maskValue is not None:
-            mask = np.logical_or(modelOutput.mask,
-                                 modelOutput == self.maskValue)
-            modelOutput = np.ma.masked_array(modelOutput, mask)
+            refOutput = self._mask_with_thresholds(refOutput)
+
+        modelOutput = self._mask_with_thresholds(modelOutput)
 
         comparisonDescriptor = get_comparison_descriptor(
             config, comparisonGridName)
@@ -655,6 +648,18 @@ def _plot_projection(self, remappedModelClimatology,
             imageDescription=caption,
             imageCaption=caption)
 
+    def _mask_with_thresholds(self, field):
+        if self.maskMinThreshold is not None or \
+                self.maskMaxThreshold is not None:
+            mask = field.mask
+            if self.maskMinThreshold is not None:
+                mask = np.logical_or(mask, field <= self.maskMinThreshold)
+            if self.maskMaxThreshold is not None:
+                mask = np.logical_or(mask, field >= self.maskMaxThreshold)
+            field = np.ma.masked_array(field, mask)
+
+        return field
+
 
 def _nans_to_numpy_mask(field):
     """