PI Product : Merged MMCR-WSR88D Reflectivities at SGP
2000.03.16 — 2004.08.09
There are substantial attenuations of MMCR signals for very large LWP and during precipitation events. We have used the nearest precipitation radar (WSR-88D) to merge two measurements to better represent such selected cases. In the near future, we are going to provide all the cumulus cases from Jan. 1997 to present whenever the two datasets are available.
The original 2 data sets:
(1) MMCR data (Mace PI products: sgp.Integrate_Column_5min-Mace.cdf ReflectivityBestEstimate(time, height); time resolution 5 minutes, and height resolution 90 meters.
(2) WSR_88D: The WSR-88D radar used located at Vance Air Force Base, OK (KVNX), approximately 59.3 km west of the SGP MMCR. WSR-88D level 2 data were used to reconstruct reflectivity profile for the vertical column above the SGP MMCR. The portion of each WSR-88D volume scan that intersects the column being sampled by the MMCR has been extracted and saved. The vertical resolution of the reconstructed WSR-88D reflectivity over the SGP site is determined by the VCPs used for each case.
The merged data set: reflectivity (Feng et al. 2008), linear interpolation is performed on the WSR-88D data to fill the 167 vertical levels, where the missing data is -9999. Merge criteria:
(1) For rain rate > 7 mm/hr, WSR-88D reflectivity replaces MMCR reflectivity;
(2) For rain rate <= 7 mm/hr, and LWP and temperature are available, attenuation corrections are applied to the MMCR reflectivity.
Xiquan Dong (701) 777-6991