1. NCAR Activities Using TAMDAR Icing Data
Marcia K. Politovich, Jamie Braid
Scott Landolt and Cory Wolff
NCAR Research Applications Laboratory

2. Projects Impacts on Current Icing Potential product
What: Determine the impact of TAMDAR icing reports (positive and negative) on icing diagnoses
Why: Do results support FAA/NWS funding of TAMDAR data stream?
Funded by: AIRDAT
Description of icing data set
What: Compile “climo” of TAMDAR icing data using RUC and CIP outputs
Why: Will help QC efforts – what are these reports, are they consistent with expected icing conditions, are we seeing inconsistencies?
Funded by: FAA

3. Laser senses 0.020” ice accreted here
Yes: activates heating cycle to melt and start over again
No: no ice detected
Uncertain:
Ttot >0C,
Tstat <0C
(ice won’t freeze onto probe)

4. CIP impact: progress
Converted TAMDAR data sets to pseudo PIREP NetCDF data
Determined HRCIP run times for study
Completed baseline verification using voice PIREPs and standard QAPDT methods

5. CIP concept
Lightning
Deep Convection m

6. High-res (5 km) CIP

7. PIREPs in CIP
Used as a boosting factor for icing potential (along with RUC SLW and VV)
Currently, only positive icing PIREPs are used:
icepotfinal = icepotini(0.35*PIREPmap + .4*SLWmap + .25*VVmap)
severity = 1-8 scale (T=1, H=8, etc.),
PIREPmap = severity/8
and weigh by proximity in space and time
Need to determine how to use negative TAMDAR icing data – decrease potential

8. CIP Comparison Three-way comparison
Baseline: no TAMDAR
Add TAMDAR positive icing reports
Add TAMDAR negative icing reports
Compare PODy, PODn, area and volume covered
What is the effect on the statistics? On the look and feel?

9. TAMDAR Icing “Climo”
Use ASCII files for location of positive icing reports
Form climatology – time of day, location, by month, etc. Where is icing being reported?
Use matching hourly 20-km RUC forecasts to pull info on temperatures, RH, condensate
Can use positive TAMDAR icing data to “verify” RUC condensate fields
Use matching CIP icing potential to check our expectations on icing – positive and negative

10. Ice Accretion? New icing severity definitions are accretion-rate based
Updated CIP severity
Accretion rate depends on object shape, airspeed, etc…
We’re interested in working with AIRDAT on this

11. More ideas?