TWP-ICE/ACTIVE MONSOON CASE STUDY

Disdrometer measurements (white symbols show all data, blue symbols show binned means) versus exponential size distributions and Z-R relations (colored lines):







Comments:

• Red solid lines show the size distribution parameters used in simulations here (fixed intercept of 10⁷ m^-4) or proposed in literature (fixed slope, Zhang et al. (2008). Red dashed lines show subjective changes that improve Z-R relationships, but these lead to underestimates of R at high LWC. The red dash-dotted line shows the results of using the third and sixth moments to fit exponential parameters (Zhang et al., 2008; input values limited to reflectivities > 30 dBZ in order to improve Z-R agreement).
• Green solid lines indicate the Steiner et al. (1995) fit to rain gauge and C-pol data. Green dashed lines indicate a Z-R relationship based on the fit to this disdrometer data shown in the bottom panel.
• Bottom panels show fits used for Zhang et al. (2008) and the conventional Z-R relationship.
• Disdrometer data are supplied by Christopher Williams and are here averaged over 1 minute. The Joss-Waldvogen disdrometer records data continuously over an area of 0.005 m², and data are originally reported at 1-min resolution.
• All measurement data have been downloaded from the DOE ARM data archive (www.arm.gov) and use in publications is subject to the policies described there. Any errors in plotting or representation shown here should be blamed on Ann Fridlind.

Preliminary summary:

• All exponential formulations overestimate reflectivity. To avoid biasing the convective/stratiform identification algorithm, the Z-R fit based on disdrometer data can be used.

Source data in time series: