1. Andrew Heymsfield and Aaron Bansemer, NCAR
OLYMPEX Airborne Data Applied to Development of Snowfall Rate-Reflectivity Relationships
Andrew Heymsfield and Aaron Bansemer, NCAR
Contributors: Mike Poellot, Simone Tanelli, Guosheng Liu, Chuntao Liu, Norm Wood

2. Objectives
Using Citation aircraft data from OLYMPEX, develop relationships between snowfall (rainfall) rate and radar reflectivity that apply to W, Ka and Ku bands
Relate APR3 W, Ka and Ku band reflectivities to snowfall (rainfall) rates derived from in-situ aircraft data for times when the ER-2 and Citation aircraft are within 2 km of each other
Compare these relationships to developed from retrieval products from CloudSat, GPM TRMM processed data sets.
Discuss preliminary results from the forward-modeling “challenge” project.

4. Evaluate Forward
Calculated Radar
Reflectivity for Rain
No assumption
about particle mass
Non-Rayleigh effects
relatively small
# 1-sec collocations:
4807

5. # 1-sec collocations=
13377

7. Rainfall Rates, derived
for P=1000 hPa

8. Snowfall rates
Derived for
P=1000 hPa

10. GCPEX Forward
Model Evaluation
APR2-Citation
Collocations
Sent Investigators
PSDs, they forward-
Modeled Ze

12. Summary and Conclusions
OLYMPEX airborne observations are a rich source of data for developing and evaluating spaceborne radar retrieval algorithms
Snowfall rates from retrievals are low relative to those developed here
Will now send out OLYMPEX data to investigators to do an evaluation of their forward models
I will discuss “representativeness” of OLYMPEX observations tomorrow