def _get_sitype_track(self, l2):
"""
Extract ice type and ice type uncertainty along the track
:param l2:
:return: sitype (array), sitype_uncertainty (array)
"""
# --- Extract sea ice type and its uncertainty along the trajectory ---
griddef = self.cfg.options[l2.hemisphere]
grid_lons, grid_lats = self._data.lon, self._data.lat
grid2track = GridTrackInterpol(l2.track.longitude, l2.track.latitude, grid_lons, grid_lats, griddef)
sitype = grid2track.get_from_grid_variable(self._data.ice_type[0, :, :], flipud=True)
uncertainty = grid2track.get_from_grid_variable(self._data.uncertainty[0, :, :], flipud=True)
# --- Translate the flags in the file into MYI-fractions ---
# The fill value of the sea ice type as changed for different product version
# To assure backwards compatibility the fill value defaults to -1 (sea ice type v1p0)
# an for newer versions it must be specified in the options
fill_value = self.cfg.options.get("fill_value", -1)
fillvalue_locations = np.where(sitype == fill_value)[0]
sitype[fillvalue_locations] = 5
sitype = np.array([*map(self.flag_translator, sitype)])
# --- Ensure uncertainty units are fractions and not percent ---
# In the sea-ice type cdr/icdr v1.0 the unit of uncertainty in percent
# while from v2.0 on the unit is fraction. Therefore a switch has been
# introduced for v2.0 that turn the unit conversion (default) off
uncertainty_unit_is_percent = self.cfg.options.get("uncertainty_unit_is_percent", True)
if uncertainty_unit_is_percent:
uncertainty = uncertainty / 100.
# All done, return values
return sitype, uncertainty
def _get_sitype_track(self, l2):
# Extract from grid
griddef = self.cfg.options[l2.hemisphere]
grid_lons, grid_lats = self._data.lon, self._data.lat
grid2track = GridTrackInterpol(l2.track.longitude, l2.track.latitude, grid_lons, grid_lats, griddef)
sitype = grid2track.get_from_grid_variable(self._data.ice_type[0, :, :], flipud=True)
# set fill values to flag 0 -> nan
fillvalues = np.where(sitype == -1)[0]
sitype[fillvalues] = 0
# --- Translate sea-ice type codes into myi fraction ---
# flag_meanings: -1: fill value, 1: open_water, 2: first_year_ice, 3: multi_year_ice, 4: ambiguous
translator = np.array([np.nan, np.nan, 0.0, 1.0, 0.5])
sitype = np.array([translator[value] for value in sitype])
# --- Get Uncertainty ---
# NOTE: There has been a change in OSI-403-d, when the `confidence_level`
# variable was replaced by uncertainty.
try:
# Translate confidence level into myi fraction uncertainty
# flag_meaning: 0: unprocessed, 1: erroneous, 2: unreliable, 3: acceptable, 4: good, 5: excellent
confidence_level = grid2track.get_from_grid_variable(self._data.confidence_level[0, :, :], flipud=True)
translator = np.array([np.nan, 1., 0.5, 0.2, 0.1, 0.0])
sitype_uncertainty = np.array([translator[value] for value in confidence_level])
except AttributeError:
sitype_uncertainty = grid2track.get_from_grid_variable(self._data.uncertainty[0, :, :], flipud=True)
return sitype, sitype_uncertainty
def _get_sic_track(self, l2):
""" Simple extraction along trajectory"""
# Extract from grid
griddef = self.cfg.options[l2.hemisphere]
grid_lons, grid_lats = self._data.lon, self._data.lat
grid2track = GridTrackInterpol(l2.track.longitude, l2.track.latitude, grid_lons, grid_lats, griddef)
sic = grid2track.get_from_grid_variable(self._data.ice_conc, flipud=True)
return sic
def get_l2_track_vars(self, l2):
# Extract from grid
griddef = self.cfg.options[l2.hemisphere]
grid_lons, grid_lats = self._data.longitude, self._data.latitude
grid2track = GridTrackInterpol(l2.track.longitude, l2.track.latitude,
grid_lons, grid_lats, griddef)
region_code = grid2track.get_from_grid_variable(self._data.region_id,
flipud=False)
# Register the variable
self.register_auxvar("reg_code", "region_code", region_code, None)
def _get_sic_track(self, l2: "Level2Data") -> np.ndarray:
"""
Simple extraction along trajectory
:param l2:
:return: sea ice concentration array
"""
# Extract from grid
griddef = self.cfg.options[l2.hemisphere]
grid_lons, grid_lats = self._data.lon, self._data.lat
grid2track = GridTrackInterpol(l2.track.longitude, l2.track.latitude, grid_lons, grid_lats, griddef)
sic = grid2track.get_from_grid_variable(self._data.ice_conc, flipud=True)
return sic
def get_l2_track_vars(self, l2):
"""
API method to map gridded region id on the trajectory
:param l2:
:return:
"""
# Extract from grid
griddef = self.cfg.options[l2.hemisphere]
grid_lons, grid_lats = self.nc.longitude.values, self.nc.latitude.values
grid2track = GridTrackInterpol(l2.track.longitude, l2.track.latitude,
grid_lons, grid_lats, griddef)
region_code = grid2track.get_from_grid_variable(
self.nc.region_id.values, flipud=False)
# Register the variable
self.register_auxvar("reg_code", "region_code", region_code, None)
def _get_snow_track(self, l2):
"""
Extract the snow depth and density track along the l2 track
:param l2:
:return:
"""
# Extract track data from grid
griddef = self.cfg.options[l2.hemisphere]
grid_lons, grid_lats = self._data.get_lonlat()
grid2track = GridTrackInterpol(l2.track.longitude, l2.track.latitude,
grid_lons, grid_lats, griddef)
# Extract data (Map the extracted tracks directly on the snow parameter container)
var_map = self.cfg.options.variable_map
snow = SnowParameterContainer()
for var_name in var_map.keys():
source_name = var_map[var_name]
sdgrid = self._data.get_var(source_name, self._requested_date)
setattr(snow, var_name, grid2track.get_from_grid_variable(sdgrid))
# Extract the W99 weight
w99_weight = grid2track.get_from_grid_variable(self._data.w99_weight)
# Apply the same modification as the Warren climatology
# Apply ice_type (myi_fraction correction) but this time modified by the regional weight
# of the Warren climatology. The weight ranges from 0 to 1 and make sure no fyi scaling is
# applied over the AMSR2 region data
scale_factor = (1.0 - l2.sitype
) * self.cfg.options.fyi_correction_factor * w99_weight
# The scaling factor affects the snow depth ...
snow.depth = snow.depth - scale_factor * snow.depth
# ... and the uncertainty. Here it is assumed that the uncertainty
# is similar affected by the scaling factor.
snow.depth_uncertainty = snow.depth_uncertainty - scale_factor * snow.depth_uncertainty
# the uncertainty of the myi fraction is acknowledged by adding
# an additional term that depends on snow depth, the magnitude of
# scaling and the sea ice type uncertainty
scaling_uncertainty = snow.depth * scale_factor * l2.sitype.uncertainty * w99_weight
snow.depth_uncertainty = snow.depth_uncertainty + scaling_uncertainty
return snow
def _get_sitype_track(self, l2):
""" Extract ice type and ice type uncertainty along the track """
# Extract from grid
griddef = self.cfg.options[l2.hemisphere]
grid_lons, grid_lats = self._data.lon, self._data.lat
grid2track = GridTrackInterpol(l2.track.longitude, l2.track.latitude, grid_lons, grid_lats, griddef)
sitype = grid2track.get_from_grid_variable(self._data.ice_type[0, :, :], flipud=True)
uncertainty = grid2track.get_from_grid_variable(self._data.uncertainty[0, :, :], flipud=True)
# Convert flags to myi fraction
translator = np.array([np.nan, np.nan, 0.0, 1.0, 0.5, np.nan])
fillvalues = np.where(sitype == -1)[0]
sitype[fillvalues] = 5
sitype = np.array([translator[value] for value in sitype])
# Uncertainty in product is in %
sitype_uncertainty = uncertainty / 100.
return sitype, sitype_uncertainty
def _get_snow_track(self, l2):
""" Extract snow depth from grid """
# Extract from grid
griddef = self.cfg.options[l2.hemisphere]
grid_lons, grid_lats = self._data.lon, self._data.lat
grid2track = GridTrackInterpol(l2.track.longitude, l2.track.latitude, grid_lons, grid_lats, griddef)
# Extract snow depth along track data from grid
sd_parameter_name = self.cfg.options.snow_depth_nc_variable
sdgrid = getattr(self._data, sd_parameter_name)[0, :, :]
snow_depth = grid2track.get_from_grid_variable(sdgrid, flipud=True)
snow_depth[snow_depth < 0.0] = np.nan
# Extract snow depth uncertainty
unc_parameter_name = self.cfg.options.snow_depth_uncertainty_nc_variable
uncgrid = getattr(self._data, unc_parameter_name)[0, :, :]
snow_depth_uncertainty = grid2track.get_from_grid_variable(uncgrid, flipud=True)
snow_depth_uncertainty[snow_depth_uncertainty < 0.0] = np.nan
return snow_depth, snow_depth_uncertainty