- pyart.retrieve.conv_strat_yuter(grid, dx=None, dy=None, level_m=None, always_core_thres=42, bkg_rad_km=11, use_cosine=True, max_diff=5, zero_diff_cos_val=55, scalar_diff=1.5, use_addition=True, calc_thres=0.75, weak_echo_thres=5.0, min_dBZ_used=5.0, dB_averaging=True, remove_small_objects=True, min_km2_size=10, val_for_max_conv_rad=30, max_conv_rad_km=5.0, cs_core=3, nosfcecho=0, weakecho=3, sf=1, conv=2, refl_field=None, estimate_flag=True, estimate_offset=5)[source]#
Partition reflectivity into convective-stratiform using the Yuter et al. (2005) and Yuter and Houze (1997) algorithm.
grid (Grid) – Grid containing reflectivity field to partition.
dx, dy (float, optional) – The x- and y-dimension resolutions in meters, respectively. If None the resolution is determined from the first two axes values parsed from grid object.
level_m (float, optional) – Desired height in meters to classify with convective stratiform algorithm.
always_core_thres (float, optional) – Threshold for points that are always convective. All values above the threshold are classifed as convective See Yuter et al. (2005) for more detail.
bkg_rad_km (float, optional) – Radius to compute background reflectivity in kilometers. Default is 11 km. Recommended to be at least 3 x grid spacing
use_cosine (bool, optional) – Boolean used to determine if a cosine scheme (see Yuter and Houze (1997)) should be used for identifying convective cores (True) or if a simpler scalar scheme (False) should be used.
max_diff (float, optional) – Maximum difference between background average and reflectivity in order to be classified as convective. “a” value in Eqn. B1 in Yuter and Houze (1997)
zero_diff_cos_val (float, optional) – Value where difference between background average and reflectivity is zero in the cosine function “b” value in Eqn. B1 in Yuter and Houze (1997)
scalar_diff (float, optional) – If using a scalar difference scheme, this value is the multiplier or addition to the background average
use_addition (bool, optional) – Determines if a multiplier (False) or addition (True) in the scalar difference scheme should be used
calc_thres (float, optional) – Minimum percentage of points needed to be considered in background average calculation
weak_echo_thres (float, optional) – Threshold for determining weak echo. All values below this threshold will be considered weak echo
min_dBZ_used (float, optional) – Minimum dBZ value used for classification. All values below this threshold will be considered no surface echo See Yuter and Houze (1997) and Yuter et al. (2005) for more detail.
dB_averaging (bool, optional) – True if using dBZ reflectivity values that need to be converted to linear Z before averaging. False for other non-dBZ values (i.e. snow rate)
remove_small_objects (bool, optional) – Determines if small objects should be removed from convective core array. Default is True.
min_km2_size (float, optional) – Minimum size of convective cores to be considered. Cores less than this size will be removed. Default is 10 km^2.
val_for_max_conv_rad (float, optional) – dBZ for maximum convective radius. Convective cores with values above this will have the maximum convective radius
max_conv_rad_km (float, optional) – Maximum radius around convective cores to classify as convective. Default is 5 km
cs_core (int, optional) – Value for points classified as convective cores
nosfcecho (int, optional) – Value for points classified as no surface echo, based on min_dBZ_used
weakecho (int, optional) – Value for points classified as weak echo, based on weak_echo_thres
sf (int, optional) – Value for points classified as stratiform
conv (int, optional) – Value for points classified as convective
refl_field (str, optional) – Field in grid to use as the reflectivity during partitioning. None will use the default reflectivity field name from the Py-ART configuration file.
estimate_flag (bool, optional) – Determines if over/underestimation should be applied. If true, the algorithm will also be run on the same field wih the estimate_offset added and the same field with the estimate_offset subtracted. Default is True (recommended)
estimate_offset (float, optional) – Value used to offset the reflectivity values by for the over/underestimation application. Default value is 5 dBZ.
convsf_dict (dict) – Convective-stratiform classification dictionary.
Yuter, S. E., and R. A. Houze, Jr., 1997: Measurements of raindrop size distributions over the Pacific warm pool and implications for Z-R relations. J. Appl. Meteor., 36, 847-867. https://doi.org/10.1175/1520-0450(1997)036%3C0847:MORSDO%3E2.0.CO;2
Yuter, S. E., R. A. Houze, Jr., E. A. Smith, T. T. Wilheit, and E. Zipser, 2005: Physical characterization of tropical oceanic convection observed in KWAJEX. J. Appl. Meteor., 44, 385-415. https://doi.org/10.1175/JAM2206.1