pyart.retrieve.create_cfad

pyart.retrieve.create_cfad(radar, field_bins, altitude_bins, field='reflectivity', field_mask=None, min_frac_thres=0.1)

This function returns a Contoured Frequency by Altitude Diagram (CFAD; Yuter et al. 1995), a 2-dimensional histogram that is normalized by the number of points at each altitude. Altitude bins are masked where the counts are less than a minimum fraction of the largest number of counts for any altitude row.

radarRadar

Radar object used. Can be Radar or Grid object.

field_binslist

List of bin edges for field values to use for CFAD creation.

altitude_binslist

List of bin edges for height values to use for CFAD creation.

fieldstr

Field name to use to look up reflectivity data. In the radar object. Default field name is ‘reflectivity’.

field_maskarray

An array the same size as the field array used to mask values.

min_frac_thresfloat, optional

Fraction of values to remove in CFAD normalization (default 0.1). If an altitude row has a total count that is less than min_frac_thres of the largest number of total counts for any altitude row, the bins in that altitude row are masked.

Returns:

• freq_norm (array) – Array of normalized frequency.

• height_edges (array) – Array of bin edges for height data.

• field_edges (array of x coordinates) – Array of bin edges for field data.

References

Yuter, S. E., and R. A. Houze, 1995: Three-Dimensional Kinematic and Microphysical Evolution of Florida Cumulonimbus. Part II: Frequency Distributions of Vertical Velocity, Reflectivity, and Differential Reflectivity. Mon. Wea. Rev. 123, 1941-1963. https://doi.org/10.1175/1520-0493(1995)123%3C1941:TDKAME%3E2.0.CO;2