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

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

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)

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

CIP concept Lightning Deep Convection m

High-res (5 km) CIP

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

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?

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

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

More ideas?