94-GHz Doppler Radar Observations of Mammatus in Tropical Anvils During Crystal- Face Experiment Ieng Jo Radar Meteorology Group Univ. of Miami Motivation Mammatus clouds are one of the most striking features of clouds associated with deep convective activity, often present at the cloud base resembling pendant bulges known as mamma. Despite copious photographic documentation of mammatus clouds, there is a limited number of observations using meteorological instruments. Turbulent activity in mammatus clouds can be hazardous to aircrafts and previous observations have provided contradictory evidence. Due to their small scale microphysical and dynamical structure mammatus clouds present an ideal testbed for cloud radar research. Crystal-Face Eastern Ground Radar Site NOAA, ETL K a -band radar Rayleigh scattering High sensitivity for cirrus clouds ARM/MMCR operational strategy (4 modes) Resolution: 8 sec, 45 m University of Miami, W-band radar Rayleigh and Mie scattering High sensitivity Single mode operations Resolution: 1.7 sec, 30 m Spatial vertical resolution ~ 30 m. Temporal resolution 1.7 seconds. Doppler velocity resolution ~ ms -1 Vertical pointing mode Sensitivity ~ -51 km 3-dB antenna beamwidth 0.24 deg 512 FFT-point Doppler spectra recording 94 GHz University of Miami Cloud Doppler Radar NOAA/ETL 35-GHzUM 94-GHz Mammatus 25 min 3 km Strong downdrafts within the mamma cores. Typical observed maximum downward velocities are 3 to 5 m/s. The highest downward Doppler velocities are highly correlated with high reflectivity values. Horizontal gradient of radar observables The Doppler spectrum width values are highly correlated with the spatial interfaces between upward and downward motions. The Doppler spectrum width seems to have contributions from both ice crystal size variations and small-scale turbulence unresolved by the radar. Time = 3.9 UTC Velocity dBZ 4 ms -1 Melting or dynamics? Vertical gradient of radar observables Radar observables at mammas side and interior Conclusions Unprecedented high resolution observations of mammatus were obtained during Crystal-Face experiment by the UMDCR The observations captured the fine reflectivity structure of mammatus clouds and significant Doppler velocity perturbations were recorded. These features were under sampled by other active sensors in the past The strong evidence of recirculating motions around individual mammatus illuminate a conceptual physical model of mamma clouds New Research Topic: Fair weather Cumuli Dynamical and microphysical structure Drizzle processes Future work Integrate remote sensors currently present at our campus such as, microwave radiometer, total sky imager, spectra radiometer and collect boundary layer cloud observation Collaborate and participate in field experiments such as Rain In Cumulus over the Ocean (RICO) Acknowledgement Dr. Bruce Albrecht Dr. Roger Lhermitte Dr. Pavlos Kollias Manuel Lonfat, and my classmates Scott,John, Ray,Melice Tom Snowdon