***PLEASE READ THE FOLLOWING REGARDING THE NATURE OF THIS ANALYSIS PRODUCT*** WCR L2 Up-Down Merged with Vertical Velocity Estimate Improved using Sounding Winds This directory contains 24 IOPs (23 Research Flights - IOP 18 had no flights) worth of data obtained from the Wyoming Cloud Radar (WCR) aboard the UWKA Research Aircraft. The data is considered an ANALYSIS PRODUCT rather than the standard WCR data offering due to an additional field (w_corrected) that has been appended to the standard Level 2 (L2) file. This analysis is only being offered with the L2 merged (up-down antennas) product. The w_corrected field employs a sounding correction to produce an estimate of the hydrometeor vertical velocity field from the WCR along level flight legs. The sounding name/time and w_corr field descriptors have been included as attributes to the .nc (netCDF) files. In general, the IPC Crouch Sounding from the SNOWIE project was employed to correct the w field. This is a single sounding closest to the center flight time for each RF in SNOWIE, at a location closest to the UWKA flight tracks in SNOWIE (Crouch). NOTES: CALCULATIONS - The relevant procedure (aka, "velcor.pro)" is as follows: w_corr_ij = (w_ij + h_uv_vector_i . beam_uv_vector_j)/abs(beam_w_vector_j); where w_corr_ij is the w_ij corrected Doppler velocity for horizontal wind contamination; i is the radar altitude gate, and i=1, ..., number of alt gates (increasing w/ first index); j is the radar profile (along flight dimension), and j=1, ..., number of profiles; w_ij is the WCR merged radial Doppler velocity* from the up-/down-pointing antennas corrected for the aircraft motion contamination and interpolated into the vertical plane; h_uv_vector_i is the horizontal wind (u and v components) from sounding (assumed to be uniform over all profiles); beam_uv_vector_j is the WCR beam-pointing unit vector (u and v components) in ground coordinates; veam_w_vector_j is the WCR beam-pointing unit vector (w component) in ground coordinates; and '.' designates a dot (scalar) product. * velocity is positive upward ASSUMPTIONS - Horizontal homogeneity of the wind profile along the flight track is assumed during the duration of the flight (steady state winds). Thus, the quality of this field is best in instances where there is not a lot of variation in u between the mountains and valleys and over the flight duration. Another approach would be to use the time-dependent Flight Level (FL) wind w_correction The sounding-based w_correction generally is superior to the FL-based w_correction, except if the wind shear is very small, yet the time-dependent variation large. SUBJECTIVE FEEDBACK - After a brief review of all 24 IOPs, it appears that using the Crouch sounding-correction generally improves the hydrometeor vertical velocity fields along level legs. This is particularly evident in the vicinity of large aircraft attitude roll variations (i.e., up-/down- draft shafts artifacts are removed during turns). One exception is IOP13 (FROPA w/ convection ahead) with four legs flown. The FL-based w_correction appears to be better than the sounding-based w_correction, which might suggest little vertical wind shear and/or a large variation in the mean wind from mountain to valley (heterogeneity in horizontal winds). REVISION DATE: May 26, 2017 by A. Tripp CONTACT/CORRESPONDENCE: For further information regarding this analysis product, please contact: Bart Geerts (Professor) or Adam Tripp (PhD Candidate) University of Wyoming Dept. Atmospheric Science geerts@uwyo.edu or atripp1@uwyo.edu